NEXT GENERATION NETWORKS
(NGN)
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Content Development Team:
The contents of this course are developed by thefollowing Instructors:
Mr. Syed Irfan Sohail Dr. Mustafa ShakirMr. Muhammad SiddiqueMr. Sajjid-ur-RehmanMr. Qasim Mansoor JilaliMr. Farrukh S. BabarMr. Irfan KhalidMr. Muhammad HussainMr. Shahab Ahmad NiaziMr. M. Asharf JavedMr. Kashif JamilMr. Salahuddin
Course Objectives:
At the end of this course the participants are expected to:
•Identify differences in legacy networks & Next Generation Networks•Describe NGN Architecture and NGN Services•Describe NGN Signaling protocols and their workings •Identify media gateways and their connectivity•Describe current and future NGN trends regarding Multimedia Services
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Traditional Networks and their Services
• Voice Services:– Basic telephony– ISDN (Digital services)– Mobile Telephony
• Video Services:– Video telephony– Cable TV– Video On Demand
• Data Services:– Site-to Site Connectivity– Internet Access
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Traditional networks Services
Traditional circuit switches:
-Meant for voice services
-Connectivity & switching
-Short Holding time
Circuit switches for Data Calls:
-Internet calls
-Longer Holding time
-Less bandwidth and less revenue
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Legacy/Traditional Networks
Focus shifted from basic telephony and supplementary to Multimedia Services for users from any place and at any time
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Services
Transport & Access
Advantage: Beneficial as a standalone systems and solutions
Disadvantage:High operational costSlow to deployDifferent devices are required for different services
Traditional networks Services
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Access n/wAccess n/w
Switches
PSTN designed for POTS, basic copper wire line voice service
Traditional PSTN Voice networks
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Traditional Data networks
Frame RelayATM
IPVirtual Connections
Branch Office
Branch Office
Branch Office
Head Office
Public Data Networks: Providing data/LAN Connectivity
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HLR
VLR
MSC
GMSCBSC
OMC
Fixed Network
BTSs
Traditional Mobile networks
Public Land Mobile Network:Providing voice services to mobile and Fixed networks
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Traditional Internet network
Internet: Data services exclusively, packet switched network with some other services
Servers
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Complicated Legacy Traditional Network
More complicated networking and construction
High CAPEXSlower deployment of new service
High OPEX
Too many sites!
MSC2
MSC1
MSC5
MSC7 MSC8
MSC3
MSC4
MSC6MSC..
Need more investment on sites and accessories
Need more staff for O&M
Need more transmissions for inter-connecting
Need more time for service deployment and O&M
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Telecom Service Requirements and Future Trends
Voice95%
SMS5%
Voice
SMS
MMS
Info Services + surf
Location Services
Transactions
Business Data
Machine to Machine
Multi Media
Voice58%
( 2002-2007 )
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Future Trends
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Future Trends
1990 1995 2000 2005 2010
Multi-service Multi-protocol
Simple Integration
All in IP evolutionCircuit switching- 〉 packet switching- 〉 All in IP 3GPP R5-R6, 3GPP2 Phase0-Phase3
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NGN Evolution & its Overview
Desire for a new platform:
User requirements increased—more bandwidth
Technology growth—intelligent nodes, switches
Fast & reliable exchange of information—high transmission speed
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New services evolution
Arrival of new Telecom services, fast packet switching and enhanced VVD laid the foundation of a New Generation of Networks or NGN for new generation of services
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What is NGN?
• NGN is Voice Over IP, bypassing the regular switches to save the investment on Switches and Trunks.
• NGN is network convergent technology, combining wireline (PSTN), wireless (GSM, CDMA and 3G) and packet data network together, for integrated voice, data and multimedia services.
• NGN is a flat telephone network over Packet Data Network, instead of traditional Hierarchy structured telephone network with reduced investment.
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Why NGN• Increased demand for bandwidth is not possible through
existing PSTN.
• Requirement for new services.
• Telecom operators wants to reduce the OPEX and CAPEX (Need one common network for all services).
• Future proof network to handle Voice, Data and Multimedia.
• Optimising and simplifying transmission links.
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NGN - Drivers
Next Generation Networks
Next Generation Networks
Operation Costcompetition
QoS configurability& verification
Meet capacityOn-demand
request
Rapid introduction of new technology Voice/Data and wire/wireless integrated managementInteroperability: Multi-vendor equipment
Rapid introduction of new technology Voice/Data and wire/wireless integrated managementInteroperability: Multi-vendor equipment
Demands for new services
Diversity in Technologies
Cope withIP & mobileenvironment
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IP/MPLS Multi-Service Bearer
NGN Core Network
VIDEOVOICE DATA
Copper Optical Wireless
PSTNPSTN
GSM/CDMAGSM/CDMA
Public Data networkPublic Data network
CATVCATV
SE
RV
ICE
SE
RV
ICE
SE
RV
ICE
AC
CE
SS
AC
CE
SS
AC
CE
SS
VOICE
data
data
VIDEO
VOICE
Legacy Networks & NGNLegacy Networks & NGN
Legacy Networks were dedicated and isolated networks with service specific signaling and routing for service connection
Limited Broadband and Multimedia services High OPEX High Service cost Long Service provision time Inefficient O&M Too many sites, too many types of nodes Outdated and aged Exchanges
NGN has a common IP core and provide nomadically accessible IP applications regardless of a specific access link or user device
Provide integrated services instead of limited service Centralized management and simple network structure,
reduce OPEX OPEX Saving from reduction of transmission, room
space, O&M center, etc. Realize the fast and cost effective new service
deployment. • Pave the way to all-IP network
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Voice and Data Networks
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Distributed Model
MG
IP
SoftSwitch
IP
H.248/MGCP H.323/SIP
TDM
TDM
Packet Network
Application Servers
O&M
Charging
IP Phone
Centralized Model
Call Control
Line Card
Trunk Card
Time Slot Switching
TDM
O&MCharging
POTS
Phone
Centralized vs Distributed ArchitectureCentralized vs Distributed Architecture
Basic & Supplementary Telephony services
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Harmonization thru Standardization
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Packet-based transfer Separation of control functions among bearer
capabilities, call/session, and application/ service
Decoupling of service provision from network, and provision of open interfaces
Support for a wide range of services and applications
Broadband capabilities with end-to-end QoS
Characteristics of NGNCharacteristics of NGN
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Interworking with legacy networks via open interfaces
Generalized mobility Unrestricted access by users to different
service providers Converged services between Fixed/Mobile Compliant with all Regulatory requirements,
for example concerning emergency communications and security/privacy, etc
Characteristics of NGNCharacteristics of NGN
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NGN Solution Benefits
Structured network architecture, smooth evolution, variety of services available
Rapid Service provisioning Cost-effective multi-service access One IP based multi-service bearer network Retain/expand customer base and increase ARPU
(Average Revenue Per User) FMC-Fixed Mobile Convergence Synergy IMS Ready
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• OPEX SavingsReduction in number of Switching nodes and
transmission linksReplacement of obsolescent equipment with new
generation IP SolutionsLower OPEX for new NGN nodes: easier network re-
engineering, less power consumption, less space needed
• CAPEX SavingsPay as you grow for Network expansion
NGN Solution Benefits
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SignalingModule
Trunk Module UserAccess Module
Service ServerSoftSwitch
TrunkGateway
TrunkGateway
TrunkGateway
SS7SignalingGateway
Contrast between PSTN and NGN
User AccessGateway
CPU
Switching Array
Intelligent Service Server
IP Core
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Evolution from PSTN to NGNEvolution from PSTN to NGN
Trunk gateway
Core switch
Call controlPacket core
network
LE
Soft switch
Tandem /toll exchange
LE
IN NMS App Server Policy Service
ISUP SG
PSTN
switch
STPTMG
PLMN
WMG (Wireless Media Gateway)
SIPPhone
H.323Phone
PCPhone
IADAMG
Packet core network
Soft switchSoft switch
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AN or Remote Unit
LS
PSTN NGN
MSTransitOffice 1
GatewayToll
OfficeOperation System SCP
MSTransit Office 2
Tandem Office to be-Reconstructed
MSAN
IP Network
NMSBilling & Customer Care APP server
Softswitch iHLR
OLT
ONU
ONU
ONUOptical Transmission
OLT
ONU
ONU
ONUOptical Transmission AN
LS
Transit Office to be-Reconstructed
Media GatewayMedia gateay
LS LS LS
FE/GEFE/GE
FE/GE
V5.2
Remote Module
Twisted-pair Cable E1E1
E1/SDH/SONET
PSTN Transit Office Optimization & Reconstruction Solution
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PSTN End-Office Optimization and Reconstruction Solution
PSTN NGN
ISDN Subscriber
DSL Subscriber
ISDN Subscriber
DSL Subscriber
Data Network
SS
Tandem Office
Gateway Toll
Office OS SCP
End Office to be-Reconstructed
LE LE
Media Gateway
E1/SDH/SONET
V5.2
FE/GE
Remote Module
Billing & Customer Care
NMS APP
iHLR
Subscriber
MSG7200 TGMSG 9000
SG7200 SG
AN orRemote Unit
Reconstructed End Office
FE/GE
FE/GE
DSLSubscriber
OLT
ONU
ONU
ONU AN
OLT
ONU
ONU
ONU MSAN
V5.2
E1/SDH/SONET
Twisted-pair Cable Twisted-pair Cable Twisted-pair Cable
Twisted-pair Cable
E1/MSTP/Build-in PDH/Build-in SDH
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NGN Architecture/Layer description and NGN Trends
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NGN Architecture
• Characteristics of Next Generation Network:• NGN is designed with an open network
framework.• NGN adopts the hierarchical architecture,
which is divided into media access layer, transport layer, control layer and service/application layer.
• NGN is based on standard protocols and packet switching network.
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NGN Hierarchical Architecture
Edge Access
Core Switch
Network Control
Service Management
Service/Application Layer
Control Layer
Transport Layer
Media Access Layer
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Access Layer
•Interworks between Core Packet Transport layer and various existing communication networks.
•Provides access of various communication terminals such as analog phone, SIP Phone, PC Phone visual terminal and intelligent terminals to the Core Packet Transport layer via various access gateways
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Core Transport Layer
The packet switching network composed of backbone transmission equipments such as IP router or broadband ATM switch as the bearer basis of the softswitch system.
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NGN Control Layer
• The control Layer combines the equipment
that manages signaling and call control
progress.
• The control handles the call setup and
controls the media gateways.
• Major components at this layer are the soft-
switches.
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Application Layer
Layer with various applications and services such as client oriented integrated intelligent services and service customization.
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NGN Network Architecture
Service Management
Network Control
Core Switching
Edge Access
IAD AMGBroadBand
Access
UMG
PLMN/3G
SG TMG
PSTN
UMG
Packet Core Network
Soft Switch Soft Switch
iOSSPolicyServer
ApplicationServer
SCPLocationServer
RADIUSServer
MRS
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Huawei U-SYS Network Architecture
Service Layer
Control Layer
Core Switch Layer
Access Layer
SoftX3000SoftX3000
3G AccessAMG5000IADBroadband
AccessPSTNPSTN UMG8900SG7000
PLMNPLMN
SoftX3000SoftX3000
IP Core Video GW
UMG8900
UMG8900
SIP/H.323 Phone
U-Path
ENIPPolicy Server
MRS6100IN
OSSiManagerN2000
LocationServer
PSTN
switchSTP
Open Eye2G
Terminal3G
Terminal
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ZTE NGN Architecture
SG MSAGNAS H323GW IAD WAGAccess IP PBX
ZXSS10 IAD Series
Broadband Access
PSTN/ISDN WirelessSS7 Network
IP Router/ATM switch
Core Packet NetworkCore Transport
Softswitch SoftswitchControl
ZXSS10 SS1 ZXSS10 SS1
Router ServerSCP AAA ServerApplication
ServerPolicy ServerService
ZXUP10 APP
AG
ZXSS10 A200
TG
ZXSS10 M100
ZXSS10 S100
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PSTN Access
TGSG
PSTN
IP Core
Softswitch APP NMS
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Control Stream
Media Stream
IP Connection
TDM Bearer Network
TG
IP Bearer Network
SGTG
CityA PSTN CityB PSTN
LS
MS LSTP
TS
LS
TS
MSLSTPHSTP
SG
SIP-T
TDM Connection
Softswitch Control Device
Signaling gatewayFE/GE FE/GE
Signalling Gateway
FE/GE
PSTN-IP Toll Traffic Splitting Solution
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Next Generation Network -Future
Metro Optical Backhaul
Resource Manager
POTS
Multi Service Edge Route
LAN
APIAD
SoftphoneSoftphone
POTSFMC
MSAN
InternetSIP Phone
XDSL/LAN/POTS
Residential Enterprise Mobile Scenario
PSTN
Media GW
SS7/TDM
SS7/V5.2/TDM
NMSENIP
Softswitch
APP Server 3rd Party
Resource ManagerSignaling GW
Multi Service Edge Route
User Profile Center
IP Core Network
IPTV SipPhone
AP
Convergence
Intelligence
Broadband
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Metro Optical Backhaul
POTS
LAN
APIAD
SoftphoneSoftphonePOTS
FMC
MSAN
InternetSIP Phone
XDSL/LAN/POTS
Enterprise
NMSENIP
Softswitch User Profile Center
IPTV SipPhone
AP
IP Core NetworkConvergence
Centralized user profile center and application layer
for service convergence and fast service deployment
Shared converged IP network for voice, data and mobile
Unified multi-service access node for diversified services, decreasing the number of access node,
Residential
Convergence-oriented
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Broadband-oriented
Metro Optical Backhaul
POTS
LAN
APIAD
SoftphoneSoftphone POTS FMC
MSAN
Internet
SIP Phone
XDSL/LAN/POTS
Softswitch User Profile Center
IPTV SipPhone
AP
Broadband
IP Core Network
Constructing high QoS network with large bandwidth
Introduce various broadband access methods to support broadband service deployment
Broadband
NMSENIP
Residential Enterprise
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Intelligence-oriented
Metro Optical Backhaul
POTS
LAN
APIAD
SoftphoneSoftphone POTS
MSAN
Internet
SIP Phone
XDSL/LAN/POTS
Softswitch
User Profile Center
IPTV SipPhone
AP
Broadband
Intelligence
Centralized user profile center, session control and application layer
•Bring intelligence to whole network
•Support fast unified service deployment
NMSENIP APP Server 3rd Party
IP Core Network
Residential Enterprise
Next Generation NetworksSignaling Protocols
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SIGNALING PROTOCOLSIN
NEXT GENERATION NETWORKS
H.323, SIP, MGCP, SIG-TRAN ETC
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• A services oriented network– Focus is on services
• Separation of services from Call Control – Switching & connectivity headaches are no
more in switches• Services are independent of the Network
– All services are independent of network control
• Open and Integrated – Multivendor environment designed by IUT &
IETF
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NGN What it actually is…..
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Distributed Intelligence of NGN
Centralized Intelligence
Distributed & Effective Intelligence
Intelligence Driven by CPE
Telephony world Internet world
NGN Services
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NGN Values
• Distributed and Open architecture
• Hierarchical architecture: four Layers
• It has an independent Network control Layer
• Easy Interfacing: for multiple vendor Gateways
• Based on Packet Switching and Standard Protocols
• It is a brand-new network integrating Voice, data and video services
Network operators should:
• Build on Core Competencies related to traditional transport services
• Eliminate inefficient current service-specific, proprietary solutions
• Enable carriers to deploy advanced services(all IP multimedia)
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Quantifying the NGN
• Signaling: used for establishing, controlling and monitoring the connections among networks and the end devices
• Provides the means (paths, ways or directions) to exchange Connection-related information
• Was simple in case of only voice • Became complex with Value Added &
Supplementary services
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Signaling in Telecommunications
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Signaling in NGN
• NGN signaling protocols: H.323, H.248, SIP, MGCP, Sig Tran, etc
User to User• Media Gateway Controller to MGWC• User to MGWC and MGWC to user• User to Soft switch and vice-versa
MGWC Protocol: H.248/MEGACO• Control of Media Gateways & media (voice, video) coding
Session Description Protocol: SDPCharacteristics of Audio/Video
Signaling Transport Protocol: (Sigtran)PSTN to NGN Internetworking
• Version 1—June 1996Multimedia conferencing on LAN,
Defined network elements & Call model
• Version 2—February 1998More efficient procedures
Authentication, encryption and security H.235
• Version 3– September 1999Expanded supplementary services H.450
• Version 5– June 2003Improved robustness, recovery from signaling errors
Use of DNS, URLs within H.323
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H.323 Signaling in NGN
• System and component Descriptions H.323• Call Model Description H.323• System Control
Packetization, message formats, H.225(Q.931)
channel negotiations H.245
• Audio Coding, Compression G.711, G.722, code standards, G.723, G.729
• Video Coding, compression H.261, H.263ISDN(video phones)
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H.323 Functions and standard references
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H.323 Components
• H.323 defines four major components for packet based communications:
Packet based N/W
Terminal
Terminal, Gateway, Gatekeeper, Multipoint Control Unit
MCUGateway
Terminal
Terminal
Gatekeeper
Terminals: Client endpoints in network say IP phones, PCs. Must support audio, G.711(64kbps) G.723.1, G.729, GSM & others
Gateways: Supports inter-operatability, translation between H.323 & PSTN, Transmission formats, Audio/Video trans-coding, optional elements
Gatekeeper: Admission control, Bandwidth control, address translation, communicates using RAS, manages all terminals, gateways, MCUs
MCUs: Supports multi-conferencing between 3 or more endpoints
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H.323 Components
• Client end points on the network• IP phones, PCs having own OS• Terminals running an H.323 protocols and the
multimedia applications.• Must support audio G.711 (64 kb/s). Several
compression coders G.723.1, g.729, GSM & others
• Should also have support for Video, data• Support for RTP used for packet media flow
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H.323 Terminals
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H.323 Terminals
Terminal Call Manager
RTCPH225
Call SigH225RAS
H245Call Cont
RTP
Audioappls
videoappls
G.771G.729G.723.1
H261H263 T120
Data
Transport Protocols & Network Interface
• Gateway provides connectivity between an H.323 network and a non-H.323 network
• By translating protocols for call setup and release
• Converting media formats between different networks
• Transferring information between the networks connected by the gateway.
• A gateway is not required, however, for comn. b/w two terminals on an H.323 network
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H.323 Gateways
• On the H.323 side, a gateway runs H.245 control signaling for exchanging capabilities
• H.245 call signaling for call setup and release• H.225 registration, admissions, and status
(RAS) for registration with the gatekeeper • On the SCN side, a gateway runs SCN-specific
protocols (e.g., ISDN and SS7 protocols)• Translation between audio, video, and data
formats may also be performed by the gateway
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H.323 Gateways
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H.323 Gateways
Interworking Call Control
Gateway Call Manager PSTN/ISDNSignaling
Call control
PSTN/ISDNSignaling
Link Control
Physical Interface
H245Control
SignRTP RTCP
H225RAS
H225Call Sign
Transport Protocol & Network Interface
• Considered brain of H.323 network• It is the focal point for all calls within the H.323
network• Provide services such as addressing, authorization
and authentication of terminals and gateways• bandwidth management and call-control services for
H.323 endpoints• An optional feature--Call-signaling routing. Endpoints
send call-signaling messages to Gatekeeper which are routed to destination endpoints
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H.323 Gatekeepers
• Gatekeeper provides bandwidth control by using messages, bandwidth request (BRQ), confirm (BCF), and reject (BRJ)
• For instance: A threshold for simultaneous connections in H.323 network is specified
• Gatekeeper can refuse for any more connections once the threshold is reached.
• The result is to limit the total allocated bandwidth to some fraction of the total available, leaving the remaining bandwidth for data applications.
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H.323 Gatekeepers
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H.323 Gatekeepers
Gatekeeper Manager
H225RAS
H245Control
Sign
H225CallSign
Billing Services
Directory Services
Security Services
Policy/CallMgt. Services
Transport Protocols & Network Interface
• MCUs provide support for conferences of three or more H.323 terminals
• All terminals participating in the conference establish a connection with the MCU
• MCU manages conference resources, negotiates between terminals in determining (CODEC) to use
• Handle the media stream• Gatekeepers, Gateways, and MCUs are logically
separate components of the H.323 standard but can be implemented as a single physical device
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H.323 Multi-point Control Units
• MCU has two Logical entities:Multipoint Controller
Multipoint Processor
• Multipoint Controller: Controls conference call for a Multicast(many users) or Unicast(to single user)
• Multipoint Processor: provides advanced functions in H323 like video mixing, audio mixing or video switching
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H.323 Multi-point Control Units
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H.323 Call Example…….
H.323 Gatekeeper
phonephonePSTN PSTNIP network
H.323 GatewayH.323 Gateway
H.225 describes how audio, video, data and control information be managedIn IP network in equipment having H.323H.245 are control signaling which includes receiving & transmitting capabilitiesLogical channel signaling etc
• Call Setup step-1:Discovery and Registration
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H.323 Call Example…….
H.323 Gateway
H.323 GatekeeperGatekeeper Request
Gatekeeper Confirm/Reject
Who is my Gatekeeper
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H.323 Gateway
H.323 GatekeeperRegistration Request
Registration Confirm/Reject
Associate 212 NXX XXXXWith IP Address 12.10.2.2
Okay!
H.323 Call Example…….
• Call Setup step-2:Discovery and Registration
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• Call Setup step-3:
H.323 Gateway
H.323 GatekeeperLocation Confirmation
Admission Request
Find where is 212 NXX XXXXCan I call that IP address 12.10.2.2
Yes, IP is identifiedThis much XX bps is may be used
H.323 Call Example…….
Location Request
Admission confirm/reject
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H.323 Gateway
H.323 Gate
keeper
H.323 Gateway
Q.931 for basic callsetup protocol
ACFSetup
H.225 using Q.931
ACF
ARQ
Connect with OLC H.245Connect with OLC H.245
H.323 Call Example…….
Logical channels for Media Streams
SetupH.225 using Q.931
• Call Setup step-4:
H.245 manages OLC like:Type of media, UDPPort # etc
ARQ
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H.323 Few Messages……..
Gatekeeper Discovery Location Request
Gatekeeper Discovery Request (GRQ) Location Request (LRQ)
Gatekeeper Confirmation (GCF) Location Confirmation (LCF)
Gatekeeper Rejection (GRJ) Location Rejection (LRJ)
Bandwidth Change Status Queries
Bandwidth Change Request (BRQ) Info Request (IRQ)
Bandwidth Change Confirmation (BCF) Info Request Response (IRR)
Bandwidth Change Rejection (BRJ) Info Request Nak ((INAK)
Terminal/Gateway Registration Call Admission
Registration Request (RRQ) Admission Request (ARQ)
Registration Confirmation (RCF) Admission Confirmation (ACF)
Registration Rejection (RRJ) Admission Rejection (ARJ)
• H.225: – RAS channel is used to carry messages used
in the GateKeeper discovery – Endpoint terminal registration
– Associates end-terminal address with its call signaling transport address
• H.225:
-- Also describes how audio, video and control information be managed in IP based n/w
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H.323 (H.225 Call Signaling)
• H.245:– Receiving & transmitting capabilities– Defines procedures for managing logical
channels– Specifies as Open Logical Channel
structure like:– Type of media and format (audio, video codexs)– Transport address Port numbers– Direction of flow which port will receive info– May identify combinations of channels audio,
video
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H.323 (H.245 Control Signaling)
• Discovery & Registration: Identify/Who am I– RAS
• Call Setup: Who I want to call– RAS/H.225/Q.931
• Call Negotiation: Our capabilities– H.245
• Media Channel Setup: Let’s open an audio channel– H.245
• Media Transport: Send the audio– RTP/RTCP
• Call Termination: We are done– H.245/H.225/Q.931/RAS
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H.323 Call Stages
• Call Setup is faster: few messages• Future protocol: SIP based phones• Has more capacity to handle more calls• It’s a newer version may discard backward
compatibility• Uses SDP like H.323 uses H.245 for messages• Establish sessions over purely IP networks for VVD• End-to-End oriented signaling protocol and similar
to HTTP
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Session Initiation Protocol SIP
• An end-to-end oriented signaling protocol which means, that all the logic is stored in end devices (except routing of SIP messages)
• Establishes sessions for features: audio/videoconferencing, interactive gaming, and call forwarding
• Enables service providers to integrate basic IP telephony services with Web, e-mail, and chat services
• signaling functions are based on H.225 recommendation• specifies the use and support of Q.931/Q932 signaling
messages
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Session Initiation Protocol SIP
• UAC make requests and the UAS return answers to client requests
• SIP defines the communication through two types of messages, The requests (methods) and the answers (state codes)
• “SIP Methods”– contains URI User Request Identifier called Request-Line
• “SIP Answers” (State Codes)– The answers or Responses of the above SIP Methods
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SIP Messages, Call & Control
• To establish sessions SIP has following components to perform the session functions:
1. User Agent: UAC (sends/receives SIP requests)
UAS (sends answers to SIP requests)
2. Servers: Proxy (establishes calls between users)
Redirect (generates redirection answers)
Register (accepts register requests, gives location and address of user)
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SIP Components
SIP relies on SDP(Session Description Protocol) to exchange session contents like H323 uses H245 for actual media exchange
(can all be in same machine)
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SIP Call Setup Example
[email protected] [email protected]
From: [email protected]
Location Server
SIP Server
[email protected]: [email protected]
OK OK
ACK ACK
Media Stream
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SIP Call Setup Example
[email protected] [email protected]
From: [email protected]
Redirect Server
SIP Server
MovedContact 135.79.24.68
ACK
ACK
Media Stream
[email protected] From: [email protected]
OK
xyz? 135.79.24.68
• SIP entities identify a user by its SIP URI (Uniform Resource Identifiers)
• Examples of SIP URI: user@domain, where domain is a full domain name user@machine, where machine is the name of the machineuser@ip_address, where address is the IP address of the machinetelephone_number@gateway, where the gateway allow to access through the PSTN to the called number
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SIP Entities and Address
* SIP identification solution, can be also based on the DNS
• SIP Messages: – INVITE --- Initiate Call– ACK ---- Confirm final response– BYE ---- Release Call– CANCEL --- Cancel request– REGISTER --- Register with LS
• SIP Response:
Client Error 404 --- Not found
Server error 500 --- Internal Server error
Client error 484 --- Address incomplete
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SIP Messages & Responses
SDP describes: Type of media (V/V/D), format (CODECS G.729, G.731 etc), transport protocol (RTP/UDP/IP) and transport address (UDP port numbers)
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SIP Requests & Responses few……
Requests (Methods) Respones (Answers)
INVITE Initiate Call 1xx Informational
ACK Confirm final response
2xx Success
BYE Release Call 3xx Redirection
CANCEL Cancel Pending request
4xx Failure of Request
OPTIONS
Features Supported 5xx Server Failure
REGISTER
Register with Location Server
6xx Global failure
• Used between SoftSwitch and IAD/AG/TMG/UMG
• The Softswitch (MGC) Controls Media Gateways by means of MGCP
• is a signaling and call control protocol used within Voice over IP (VoIP) systems that typically interoperates with the public switched telephone network (PSTN)
• In essence MGCP is a Master (softswitch) and Slave(Media Gateways) Protocol
• MGCP uses SDP for media transporting
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Media Gateway Control Protocols-MGCP
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MGCP Call Flow Scenario
SG
SS
RTP/UDP/IP
phone phone
LE LE
TMG/UMG 1 TMG/UMG 2
SG: To establish call b/w PSTN & SS
IAM
IAMACM
MDCXCRCX
ACM
CRCX
RESP
LEGENDS: IAM- Initial Address MessageACM- Address Completion MessageCRCX- Create ConnectionMDCX – Modify connection (add video)RESP – Response to connection
Media Stream
91
MGCP Messages…….
Command Direction of Flow and Command itself
Endpoint Configuration
MGC to MG EPCX
Create Connection MGC to MG CRCX
Modify Connection MGC to MG MDCX
Delete Connection MGC to MG DLCX
Notification Request MGC to MG RQNT
Notify MG to MGC NTFY
Audit Endpoint MGC to MG AUEP
Audit connection MGC to MG AUCX
Restart In Progress MG to MGC RSIP
92
MGCP Call Flow Scenario
OFF Hook
ACM
ANM
IP NEWTORKRESP
RESP
MDCX
OFF hook
Ringing
IAM
MGCP
CRCX
MGCP
IAM
ACM
ANM
CRCX
RESP
Phone
MG2LEX1 MGC MG1
Phone
LEX2MGC
• MEGACO was designed after some limitations in MGCP like MGCP could handle low density
• ITU-T developed MDCP whereas IETF had developed MGCP
• A compromise between the two originated in the form of MEGACO-Protocol or MEGACOP
• ITU-T (SG-16) also developed H.248 in parallel to MEGACO
• Finally ITU-T & IETF agreed upon that both MEGACO & H.248 shall be identical
93
MEGACO/H.248, point of origin…
• MEGACO defines the rules/protocols for the Sofswitch to control MGWs
• Typically MEGACO/H.248 provides support for media streams
• It provides support for VoIP & multimedia support for PSTN or VoIP within the IP network
• MEGACO provides base architecture for controlling MGWs –how MGWs can be controlled by SS (MGC)
• MEGACO/H.248 works for a distributed architecture
94
MEGACO/H.248, functions
• MEGACO provides:• Total control over Media Gateways MGs• Call admission and billing• Signaling interface to PSTN• Translation for H.323 or SIP protocols
The Softswitch (MGController) instructs MGWs like:• To sense off-hook condition• To apply dial-tone & collect dialed digits• To ADD any call connection and its context (coders
required)• To add UDP port numbers etc
95
MEGACO/H.248, workings..
• Two terminologies are used:– Termination and Context
• Termination:– A termination is a logical entity that transmit/receive
media stream or control streams– For example: Endpoint is a termination
• Context:-- It is the association between two Terminations
(Endpoints)
For example: between two Endpoints (Local Call)
between two RTP ports (Transit Call)
96
MGCP and MEGACO base model
• MEGACO Terminations and Context
97
MGCP and MEGACO base model
Termination Termination
Termination
Termination
Termination
Termination
X
X
SimpleContextVoice Call
MultimediaContext(Conference Call)
NullContextNo Connection
Context
Context
• MGCP terms basic constructs as Endpoints & Connections
Endpoints: source/sink of data
Connections: an association between two Endpoints
• MGACO terms basic constructs as Terminations & ContextsTermination: an entity within a MGW that source/sinks
data
Context: an association between two Terminations
Possible Contexts: Origin & Dest in same MGW (local call)
Between two diff MGW (transit call)98
MGCP and MEGACO base model
• Sofswitch MGC creates new Context inside MG by ADD
• MGC adds, subtracts Terminations to a Context
• MGW NOTIFIES MGC of events (off-hook, on-hook) inside MG
• MGC audits (checks) Context & Termination between MGWs
• MGC uses Service Change command (adding video/data) during a call to inform MGW
99
MEGACO and SoftSwitch!
• MEGACO/H.248 define aspects of signaling as Packages:– Commonly defined functions like:
• Connectivity, Transfer and Hold etc• Examples of Packages are:
• Transactions = Number• Contexts = Number, $ • Termination = Identity or $• Package Data = off-hook, on-hook, port #• Events, Signals, statistics = ring back tones, tone
itself, time to ring
100
MEGACO Packages….
Messages Description of Messages
Add Addition of a Termination to a context. First Add message creates new context
Modify Modification of features of termination, dial tone
Subtract Removal of a termination fro a context (disconnection)
Move Removal of a termination from context and addition of this termination to another context (Conference Call)
Audit Value Requests Information about features, events, signalsWhen SS learns features like PRI/BRI or any other
Audit Capabilities
Requests Information about all possible features, events, signals allowed for this termination
Notify Notification on Events (off-hook, on-hook)
Service Change Notification of changes of termination like dead, bad
101
MEGACO Messages
• SIGTRAN:• SIGnaling TRANsport to carry SS7 signals over the
Internet• PSNT’s signals are being carried over IP network after
converting from SS7 to IP signals• Underlying transport vehicle is SCTP (Signaling Control
transmission Protocol) to carry SS7 over IP• PSTN signals SS7 are transmitted to SG (Signaling
Gateway) which in turns converts SS7 into SIGTRAN signals
• SIGTRAN signals are sent to a SoftSwitch or to next Signaling Gateway SG
102
SIGTRAN Protocols….
• Basic function of SIGTRAN:• To transport PSTN (SS7) signals over IP keeping
the functions & requirements of PSTN• Idea is to transport ISDN(Q.931, ISUP, SCCP
etc) messages between IP nodes (SG, MGC, MGW) or to an IP-based database
• To provide signaling capability for Call Management and to provide media paths for IP real-time traffic
• Real-time traffic can be Voice, Music, video which needs instant transportation
103
SIGTRAN Protocols……
104
SIGTRAN Protocols Model
Adaptation Protocols
Common Signaling Transport SCTP
Standard IP protocols
Adaptation protocols-to make TCP/IP look like an upper layer protocols MTP3 (which are MTP1, MPT2, MTP3 all SS7 signals)
Redefines newTransport service
Carries SS7 signalsover IP runway
The Real IP Standard Transport means
Upper Layer protocols
105
Integration of SS7 & IP protocolsSS7ISUP
SCCP users,RANAP, TCAP etc
Q931SCCP
M2UA SUAM2PA M3UA IUA
MTP3
MTP2
2904 3565 2905 9900 1401
SCTP
IP
• Ease of deployment: No need to distrupt SS7, future enhancements are transparent
• Better Efficiency: Using IP over SDH and IP over fiber can achieve much higher throughput
• Flexible architecture: IP signaling is flexible than TDM-based legacy networks
• Enhanced Services: Implementation of a core IP network facilitates a variety of solutions and value added services (VAS)
106
SIGTRAN benefits…..
107
All Signaling Protocol scenario….
SGSG
H.248
PSTN
AGW
SIGTRAN
H323 /SIP
SIP-T/BICC
SS7
GSM MSC
TMG/UMG
SS7
SIGTRAN
SS SS
SIP Phone
MAPPhone BPhone A
PSTN
phones
H248
TMG/UMG
E1E1
* SIP-T: SIP for Telephone
• ISUP—ISDN User Part• SCTP– Stream Control transmission Protocol• RANAP– Radio Network Access part• TCAP– Transaction Capability part• MTP1, 2 3 – Message Transfer Part 1, 2 ,3• M2UA, M3UA – Message 2 User Adaptation,
Adaptation 3• IUA– ISDN User Adaptation• SUA– SCCP User Adaptation• SCCP– Signaling Connection Control Point
108
Protocol abbreviation used….
109
NGN Components/Elements and their Description
110
Multi Service Core Network
Multi Service Core Network
Media Gateway
SG
Softswitch
Operation Support System Gateway (OSS-
Gateway)
NGN Elements
• Softswitch (SS or MGC)
• Media Gateway (MG)
• Signaling Gateway (SG)
• Core Network
• Management and Support
Systems
• Application and Feature Server
• NGN Protocols
111
Access Identities
• SG: Signaling Gateway
• TMG: Trunk Media Gateway
• AMG: Access Media Gateway
• UMG: Universal Media Gateway
• IAD: Integrated Access Device
• MSG: Multi Service Gateway
• BGW: Broadband GateWay
112
Introduction To Gateways
113
Media Gateways The function of a media gateway is to
adapt user data to the backbone network based on a packet switching technology (IP ).
Terminates voice calls from the TDM, compress and packetize the voice data, and delivers the compressed voice packets to the packet network.
Receives the voice packets from the packet network, unpacketize and uncompress them, and deliver them to the TDM.
Controlled by the Softswitch
114
Media Gateways as Access Gateways (AG)
V.24V.35E1
POTSISDNVOIP
ADSLADSL2HDSL
SHDSL
LAN
The AGW equipment is installed in the Access Network. The Access Gateway (AG) provides narrowband and broadband service access. The AG transfers subscriber line data such as voice, modem and fax across the core network of NGN through media stream conversion.
IP/MPLS
115
Media Gateways as Trunking Gateways (TG)
LocalExchange
LocalExchange
MGW MGW
TrunkExchange
Speech circuits (TDM)
TrunkExchange
IP packets
Trunk Media Gateway (TMG) is resident between the circuit switched networkand the IP packet switched network. It provides functions of format conversionbetween pulse code modulation (PCM) signal streams and IP media streams .
IP/MPLS
116
Residential Media Gateway (RG)
RMG adopts the Voice over IP (VoIP) technology to encapsulate analog voice signals into data packets that can be transmitted over packet-switched network, in order to provide telephone service over global IP network at a very low cost.
IP/MPLS
Customer
Premises
117
IAD: Full Series Products
1-port 2-port 4-port 8-port 16-port 32-port
IAD208 Series
IAD101A
IAD101E IAD102E IAD104E IAD108 Series
IAD132E(T)
IAD116E-A
EPhone
video terminal
Terminal
Capacity ranges from 1 port to 32 Optional FE/ADSL/VDSL uplink Support Fax/Modem
118
Huawei Universal Media Gateway: UMG8900
Large Capacity: 7168 E1, 112*STM-1 (Trunk side) POTS users: up to 1,000,000 V5 users: up to 1,000,000 PRA users: 7,168 (30B+D or 23B+D) BRI users: up to 500,000
Carrier-class reliability design Interfaces: E1/T1/STM-1.FE/GE,ATM STM-
1/E3 and POS STM-1/STM-4 Protocol supported:H.248, PRA,R2,
SIGTRAN(M2UA,IUA,V5UA) and V5 Local TDM switching function (128K*128K)
119
Connectivity Of Access Gateway in Network
120
Connectivity Of Universal Media Gateway
121
Connectivity Of Trunk + Signaling Gateway
122
Connectivity Of Trunk + Access Gateway
123
Connectivity Of Residential Media Gateway
124
Communication B/W Softswitch & UMG
125
Signalling Gateways
126
Signaling Gateway: SG7000
Process capacity: 5120 64kbps links or 640 *2Mbps links Interfaces: E1/T1 and FE Protocols supported: SIGTRAN (M3UA/M2PA/SCTP) and SS7 Built-in STP Embedded signaling trace analyzer
The Signaling Gateway (SG) converts PSTN signaling between TDM bearer mode and IP packets mode.
127
Signaling Gateways Function (SG-F)
• It encapsulates and transports PSTN signaling protocols
(eg. SS7) using SIGTRAN to the MGC-F or another SG-F.• For mobile networks, encapsulates and transports
PSTN/PLMN signaling protocols (eg. SS7) using SIGTRAN
to the MGC-F or another SG-F
• The interface from the SG-F to the other entities is a
protocol interface when the SG-F and MGC-F or other SG-F
are not co-located (eg. SIGTRAN).
• One SG-F can serve multiple MGC-Fs
• Application protocols include SIGTRAN, TUA, SUA and
M3UA over SCTP
128
Introduction To Softswitch…
• The control Layer combines the equipment that
manages signaling and call control progress.
• The control handles the call setup and controls
the media gateways.
• Major components at this layer are the soft-
switches.
129
• As a SoftSwitch product, SoftX3000 is located at the core control
layer of NGN scheme.
• SoftX3000 acts as a generic Call Controller in the packet-switched
network, supports the interworking between PSTN, H.323, SIP,
and MGCP domains.
• SoftX3000 provides H.248 and MGCP based bearer control.
• In the NGN solution of Huawei, SoftX3000 acts as the core of
NGN, interworking with other NGN components through the open
network adopting distributed standard protocols.
Softswitch…
130
Location of SoftX3000
• SoftX3000 is applicable to the network control layer of NGN and implements call control and connection management of voice, data and multimedia services based on the IP network.
131
Control Function Of S.Switch
SoftSwitchSoftSwitch SoftSwitchSoftSwitch
3G AccessAMGIADBroadband
Access
PSTNPSTNTMG
SG
PLMNPLMN
IP Core Network
UMG
UMG
Call control path
Talking Path
132
Next Generation Voice Switching the “Softswitch” concept
Soft switches are software-based multi-function network gateways (running under Unix or Windows)
that act as interfaces between circuit switched and packet-switched networks
133
Role of a Softswitch
Provides the call control and the Media Gateway control for the NGN
The name softswitch is used because many switching functions handled by large monolithic systems in the circuit switched world are instead emulated by software systems.
The term Softswitch refers to a Call agent or a Media Gateway Control (MGC)
134
MGW MGW
IP/RTP Media Packets
Call Signaling over IP
Media Gateway Control
Signaling
IP Core
Softswitch
Role of a Softswitch
135
Key components of softswitch architecture are:• Call agent / Call controller: it performs call control
functions
• Application Server (AS) provides enhanced features which is not available in Softswitch host.
• Operating Support System (OSS) as network management, billing support, etc.
• Signaling Gateway (SG) as interface to CCS-7 (STP)
• Trunk Gateway (TG) as interface to TE or LE of PSTN
• Access Gateway (AG) as interface to CPE
Softswitch System Architecture
136
Softswitch Functions
The main functions are:• Call control
• Media gateway access control
• Protocol processing
• Routing
• Authentication
• Charging
• Application Programming Interfaces (API) for 3rd party Servers
137
Softswitch Services• Softswitch can be used as an end office (C5 office),
tandem office (C4 office), toll office, International gateway office and IN SSP
• Voice services
– Basic voice services
– Supplementary Services
• IP fax services
• IP CENTREX services
• Multimedia services
• IN services
138
Softswitch Service Provisioning
• Basic and Supplementary Services– Abbreviated Dialing, Automatic call back, Alarm ring service,
Call waiting, Three-way call and Centrex, etc.
• Traditional IN services– 300, 800, Account card service, etc.
• New Revenue generating services– Web 800, Click to dial, Web Service Customization,
Synchronization browsing, One Number, Voice Mail, Unified Message (UMS), Short Message.
• Video and Multi-media services– Video phone, multi-media TV conference.
139
Huawei Softx3000 Softswitch
Legacy Switch
SoftX3000
High Capacity & Integration 2,000,000 POTS 2,000,000 V5 Subscribers 2,000,000 SIP Terminals 1,000,000 H.323 Terminals
High Performance 16M BHCA
Perfect Scalability 150,000 subs / frame and
smoothly expansion Fewer power Consumption
Power consumption < 4.5KWBig Saving of 40% OPEX !
Nodes, Space, Power, Staffs……
140
Softswitch Networking Solutions
• Long Distance VoIP Solution with Softswitch + Trunk Gateway configuration for long distance VoIP service.
• Local VoIP Solutions with Softswitch + Media Gateway, Softswitch+IAD、 Softswitch+AccessGateway, Softswitch+Intelligent Terminals for local VoIP and Data services.
• Flexible access solution for group subscribers such as school, enterprise, government institute depending on network condition and accessing scale.
141
SoftX3000
UMG8900
iManager
SoftX3000
UMG8900(Main control
frame)
IN
IP corenetwork
LMT
PSTN
EnterpriseUser
UMG8900(Userframe)PBX V5 AN
CDMA 450
SoftSwitch as a Class 5 Solution
142
Soft Switch as a Class 4
SoftX3000
UMG8900
H.248/SIGTRAN
AppServer Route/PolicyService
SNMPPARLAY/SIPINAP
Switch
H.248/SIGTRAN
NMS
SoftX3000
UMG8900
SIP-T/BICC
IN
LDAP/TRIP
Packet/TDMbearer netwrk
Switch
SS7/PRI/R2 SS7/PRI/R2
PSTN PSTN
143
Interface and Protocol
• An interface is the connection point between two
adjacent network entities, and a protocol specifies the
principles to be followed for information interchanging
over such connection points (interfaces)
• Different protocols are usually used on different
interfaces and maybe on the same interface as well.
144
Soft Switch Interfaces and Protocols
MRS
IADAMG
TMG
SG
SIP
SIGTRAN
H.248
MGCP
MGCP/SIP/H.323
MG
CP
/ H
.248
EPhone
SIP
SIP
H.323
MML/SNMP
NMS
FTP/FTAM
BC
Soft SwitchSoftSwitch
SS7
H.323
PSTN
SCP
INA
P
PA
RL
AY
APP Server
SIP
/INA
P
MG
CP
/ H
.248
145
SoftX3000 Signaling Classification
• Signaling transport protocol – Signaling transport layer protocol provides SoftX3000 with signaling transport services. These are MTP (PSTN), INAP (IN), M2UA,M3UA (User adaption layer protocols for MTP2 & MTP3),SCTP etc.
• Bearer control protocol - is a kind of master/slave protocol used for Media Gateway Controller (MGC) to control Media Gateways (MGs) from external call elements like a Call Agent (SoftX3000). Example is MGCP and H248(MEGACO).
• Call control protocol – A protocol used to control call setup, connection and termination. The call control protocols used in SoftX3000 are ISUP of SS7 & for switched circuit network, SIP and H.323 for call control in packet switched networks.
NGN Gateways & Application Servers
146
NGN Gateway Systems Access/Residential Gateway
• Network Access Gateway (including Firewall, NAPT, DHCP etc.)• Residential Border Gateway
• Media Gateway• Access/Trunk Media Gateway
• Radio Gateway• BRAS (Broadband Remote Access Server)
Softswitch• Call Server, Session Controller• Signalling Gateway including Media Gateway Controller
PSTN Gateway• PSTN Emulation and Simulation
Trunk and Border Gateway• Interconnection Border Gateway
Application Server Gateway• Parlay/OSA Gateway• OperAPI Gateway
147
NGN Control and Management System -1
Transport Resource/Policy Control System• Transport Policy Management System including PDF/PEF• Multimedia Resource Controller or Resource Manager• Bandwidth Broker and Bandwidth Manager
Mobility Support System• HLR/VLR, HA/FA etc.• Location Service Control System
• Location Control Server Packet Gateway Control System
• Various Gateway Controller including Media Gateway Controller
Network Access Control System• Admission Control and gate control system• DHCP Server, NAPT, Firewall etc
148
NGN Control and Management System - 2 IMS-based Session Control System
• P-/I-/S-CSPF• Session Control Proxy System (i.e., P-CSCF, Proxy VoIP
Gateway, etc)• IMS-MGW (Media Gateway) and IMS-MGC (Media Gateway
Controller)• IMS-Resource Controller
User Profile Database System• Including Transport/Service/Terminal/User Authentication and
Authorisation System• AAA Server, HSS etc.• User (and Terminal) registration system• Subscription Location
149
NGN Control and Management System - 3
Charging and Billing System• Charging Trigger and Charging Collection System• Online Charging System including Rating system• Account Management System
Traffic Management Server• Traffic Management System
Application Control Server• Broadcast Control Server• Home Gateway Control Server• RFID Control Server• Multimedia Application Control Server
150
NGN Application Systems Home Gateway
• Including intelligent Home server• STB Management Server
Media Resource Processing Server• Media Resource and Processing Gateway• Multimedia Resource Function Processor
Application Server• Interactive Application Server or SIP-based Application
Server • Messaging Server, Presence Sever, Conference Server• VoD Streaming Server, IP-TV or DMB Server• OSA Application Server• RFID Server, Telematics Server• Web Hosting Server
151
Gateway Controller
• The Gateway Controller is one of the key functional units of the Softswitch.
• The Gateway Controller holds the call processing rules, but uses the Media Gateway and Signaling Gateway to perform the job. It is the responsibility of the Signaling Gateway to perform call set-up and teardown.
• In addition, it interfaces to the OSS and BSS systems. Often this unit is referred as Call Agent or Media Gateway Controller interchangeably.
• Sometimes the Call Agent by itself is referred as a Softswitch.
• This component communicates within other parts of the Softswitch and also the external networks using different protocols.
152
Gateway Controller
• The Gateway Controller is responsible for bridging networks with different characteristics, including the PSTN, SS7, and IP networks.
• This bridging function involves validation and initiation before establishing phone connections.
• It is responsible for managing voice and data traffic throughout the various networks.
• It is often referred to as a “Call Agent” (because of its Call control messaging functions).
• Also is referred to as a “Media Gateway Controller” (because of its Media Gateway Control functions).
153
Functional RequirementsGateway Controller
• Call control engine• Voice call establishment protocols: H.323, SIP• Media control protocols: MGCP, Megaco
H.248• Class of service and quality of service control• SS7 control protocol: SIGTRAN (SS7 over IP)• SS7 processing (when using SigTran)• QoS related protocol message handling such
as RTCP
154
• Routing, including:– Routing component: local dial plan (E164 to port mapping)– Digit analysis overlap and/or inblock signaling– Digit translation support for IP, FR, ATM and other networks
• Call Detail Records (CDR) for billing• Bandwidth management control• Provisioning for Media Gateways:
– Assignment and real time configuration of DSP resources– DS0 channel assignments– Voice transmission (coding, compression, and packetization)
• Provisioning for Signaling Gateways:– SS7 variants– Process Timers– Linkset configuration– Point code or routing configuration
• Gatekeeper registration
155
Functional RequirementsGateway Controller
System Characteristics Gateway Controller
• It is CPU intensive. A multi-processor system is most preferred
• A large in-memory database required• A large memory capacity will also enable multiple
processes to live in memory without excessive paging activity.
• It deals mostly with IP traffic • A sufficient amount of high-speed connectivity may be
required• A dual-redundancy approach for network connectivity
is normally required• It requires support for a variety protocols• Disk storage is primarily used for logging
156
Signaling Gateway
• A Signaling Gateway creates a bridge between the SS7 network and an IP network, under the control of the Gateway Controller.
• A Signaling Gateway causes a Softswitch to appear like an ordinary SS7 point code (SS7 node) in an SS7 network.
• The Signaling Gateway only handles SS7 signaling; a Media Gateway handles the voice circuits established by the SS7 signaling mechanism.
• SIGTRAN defines a suite of protocols and user adaptation layers for transporting signaling information over IP-based networks.
• If SigTran is used as the protocol between the Gateway Controller and the Signaling Gateway, then only MTP1, MTP2, and SigTran reside on the Signaling Gateway
157
A Signaling Gateway usually supports the following layers: SCTP, which is responsible for reliable signaling
transport, streaming, congestion avoidance and control
M3UA, which supports the transport of ISUP, SCCP, and TUP messages over IP
M2UA, which supports congestion control and the transport of MTP3 messages
IUA, which supports the Q.931/Q.921 interface M2Peer, which supports the MTP3-to-MTP2
interface
158
Signaling Gateway….
Functional Requirements Signaling Gateway
• A Signaling Gateway must support the following functions:• It must provide physical connectivity to the SS7 network
via a TI/El or Tl/V.35 physical connection• It must be able to transport SS7 information between
Gateway Controller and Signaling Gateway via an IP network
• It must provide a transmission path for voice, video, and optionally data. (Data transmission may be supported within the Media Gateway.)
• Provide Highly Available SS7 operation for telecommunication services
159
System Characteristics Signaling Gateway
A Signaling Gateway has the following system characteristics: It is I/O intensive, but not very CPU intensive. A maximum amount of memory should be
available to hold state information, configuration information, the point code map, alternate routes, etc.
A disk storage is primarily used for logging; a small capacity may be adequate.
The Ethernet interface (to the IP network) may require dual redundancy.
160
Signaling Gateway Characteristics
It may interface with the SS7 network by using a T1/E1/E1, with a minimum 2 D-channels, and a maximum 16 D-channels.
Performance and flexibility can be increased using a H.110 or H.100 bus.
High Availability is a requirement, multiple Signaling Gateways or signaling links are available. Redundancy is built into SS7 networks by design
161
Convergence of SS7 and IP networks
162
Call Control Functionality
163
164
SEGway X401 Signaling Gateway
• Ability to scale upto 1408 SS7 links with HSL, 1000SIGTRAN M2PA/M3UA/SUA associations.
• 14 slots available for I/O and application server blades thus unprecedented flexibility to interface with traditional SS7 and IP-SIGTRAN networks
165
SEGway X301 Signaling Gateway
• Ability to scale upto 128 SS7 links
• Six payload slots available for low TDM and high speed (IP-SIGTRAN) this solution can be used to manage SS7 networks and connect with multiple interconnectivity partners.
Application Server
• Application Server generates application documents (VoiceXMLpages) in response to requests from the Media Gateway via the internal Ethernet network.
• The application server leverages a web application infrastructure to interface with data stores (messages stores, user profile databases, content servers) to generate documents (e.g., VoiceXML pages).
• AS provide interoperability between applications like WAP, HTML, and voice allowing the end user to simultaneously input voice command and receive presentation via WAP or HTML.
166
Application Server vs. Media Server
Application Server
IP Network
Media(RTP)
Signaling (SIP)
Media Server
Functions of a Media ServerAudio Tones &
AnnouncementsAudio Tones &
AnnouncementsDTMF Detection
& GenerationDTMF Detection
& GenerationAudio Bridging
& MixingAudio Bridging
& MixingAudio Recording
& PlaybackAudio Recording
& Playback
SpeechRecognition
SpeechRecognition Text to SpeechText to Speech
VideoAnnouncements
VideoAnnouncements
Video Bridging& mixing
Video Bridging& mixing
Video Recording & Playback
Video Recording & Playback
Fax Detection& Processing
Fax Detection& Processing
Hot WordSpotting
Hot WordSpotting
Video SwitchingVideo Switching
Video Transcoding
Video Transcoding
AudioTranscoding
AudioTranscoding
Media Server Control (SIP with
VoiceXML,MSML)
Com
man
d Resp
on
se
Functions of an Application ServerService Specific Logic
(ACD, IVR, Conf, Speech)Service Specific Logic
(ACD, IVR, Conf, Speech)
Service Mgmtand ProvisioningService Mgmt
and Provisioning
Call SignalingCall Signaling
Service Databases(ie. for screen-pops)Service Databases
(ie. for screen-pops)
Billing InterfaceBilling
Interface
Service CreationService Creation
RTP = Real Time ProtocolSIP = Session Initiation Protocol
167
Aims of Application Servers
• For building integrated, enterprise-class applications that share information, deliver services, and automate collaboration among networked companies at Internet volume and speed• separate of presentation, business logic, and data• provide the underlying core functionality necessary for
the development and deployment of business-driven application
• connect legacy systems, and Web Services
168
The Reason to Adopt A.S
• applications with complex business logic• potentially servicing tens of thousands of
concurrent users in real-time• require a scalability and reliability• Distributed system
– Stock trading system– Banking application
169
What we need
• RMI• Load balancing• Transparent fail over• Back-end integration• Transaction• Clustering• Dynamic redeployment• Clean shutdown
• Logging and auditing• System management• Threading• Message-oriented
middleware• Object life cycle• Resource polling• Security• Caching
170
What do they provide?• Speeds application development and relieves developers of the
effort and expense of creating these crucial services on their owno Load balancingo Fault toleranceo Web Serviceso Legacy integrationo Transaction managemento Securityo Messagingo Multi-threadingo Persistenceo Database connectivityo Resource poolingo Development, testing, and packaging facilities
171
Single Server/Clustered Servers
172
J2EE based…
• BEA WebLogic Java Application Server • IBM WebSphere Java Application Server• Oracle 9i Java Application Server • Sun ONE Java Application Server (iPlanet)• HP Application Server (HP-AS) (Bluestone)• JBoss Application Server • Enhydra Application Server
173
J2EE Components used..• Java Servlets & Java Server Pages (JSP)• Enterprise Java Beans (EJB)• Java Transaction API (JTA)• Java Transaction Service (JTS)• Java API for XML Parsing (JAXP)• Java Messaging Service (JMS)• Message Driven Beans (MDB)• Remote Method Invocation (RMI)• Java Database Connection 2 (JDBC2)• Java Connector Architecture (JCA)• Java Naming and Directory Interface (JNDI)• JavaBeans Activation Framework (JAF)
174
Three layered architectureof A.S
• The presentation layer – managing the user interfaces of applications,
including desktop applications, Web browsers, and pervasive devices
• The business layer– contains the business logic
• The back-end layer– provides connectivity with enterprise systems
and databases
175
Hosting Organization
Presentation
Persistence
LogicLogic
Subscriber 1
Subscriber 2
Subscriber 3
176
Three layered architectureof A.S
Presentation Layer
• Thin clients– such as Web browsers that send HTTP requests
and receive HTTP responses for static HTML or dynamic Web pages built by Java Servlets and Java Server Pages (JSPs)
• Thick clients– such as Java applets and applications, ActiveX
controls, or Visual Basic clients that run on a desktop and communicate with BEA WebLogic Server through CORBA, Java RMI,IIOP, or COM+
177
Presentation Layer
• Pervasive devices– including wireless phones, PDAs, smart appliances,
and other emerging remote clients that communicate with the server via specific and usually very compact • can generate WML pages from Servlets and
JSPs.• Web Services
– that connect to the system using Web Services technologies, such as SOAP,UDDI, and WSDL
178
Presentation Layer
• Provides a Web Server• Servlet and JSP results caching and JSP tags
caching• provides high-reliability, scalability, monitoring,
and other features required by enterprise applications
• plug-ins for Apache, iPlanet, and Microsoft IIS Web servers
179
Additional Features• Virtual hosting
– www.company1.com and www.company2.com• Clustering
– scalability and high-availability– insulates clients from hardware or power failures by
eliminating single points of failure• Load balancing
– Incoming requests can be distributed across multiple instances of AS
180
Additional Features
• High availability with transparent fail-over • The data contained in Web components can
be replicated across multiple machines• In the event of a failure, current client session
information is maintained• disk-based persistence• in- memory replication of a client ’s session state
181
Business Layer
• contains the application’s business logic independent of the user interface, including distributed components, running in the application server environment
• Enterprise Java Beans
182
Examples of transactions involving mail application server
• Establishing connection between mail APIs (application program interfaces) and mail server
• Updating mails by inserting, adding, replacing, or deleting
• Querying for the mails• Terminating the connection between the API and the
mail server
183
Responses to Requests by An AS
The server Gets from the collaborating or
independent mobile devices of an
enterprise From a distributed mobile computing
system The server processes these requests Generates responses
184
Examples of web database and enterprise application servers
IBM DB2 database server IBM DB2 is an RDBMS (Relational Database
Management System) data server from IBM
DB2 EveryPlace version run on handheld devices
Enterprises application logic processing at the server
185
Examples of web database and enterprise application servers
• Oracle 9i database Server RDBMS Oracle9i server has a large number of features and it supports XML documents and has an option for cluster database
186
Some Application Servers
Web Generic application servers for Java-based web applications (Microsoft, Sun, and Netscape) with additional support for wireless network and mobile devices
IBM WebSphere Application Server with specialized mobile Web computing application server (it supports J2EE Web applications and XML databases)
IBM Domino Application Server for workgroups, email applications, and support for handheld and Windows CE devices
187
Some Application Servers
Microsoft Mobile Information Server (e.g., for messenger and email)
Oracle 9i Application Server for database services with mobile support
Puma and Synchrologic iMobile Suite for data-synchronization services
Nokia WAP (Wireless Application Protocol) Server for wireless Internet WAP applications
BlackBerry Enterprise Server (BES)
188
189
Java Naming and Directory Interface (JNDI)
• Client API provides naming & directory services for Java Apps
• Does not replace DNS, CORBA, RMI etc
• Allows multiple directory services co-exist
• Provides a federated name server
Databases
• JDBC (Java Database Connectivity)– Thin clients – servlet,JavaServer Pages (JSP)– Thick clients – RMI to remote databases– most recommended way is to use entity
beans and benefit from the underlying services
– Connection pooling
190
Integration• Integrating new applications with any legacy
Enterprise Information System (EIS)• J2EE Connector Architecture (J2CA)• CORBA
– integration with legacy systems that implement the CORBA specifications
• COM/DCOM (COM+)– bi-directional interoperability with Microsoft ’s COM+
• can access data in Microsoft applications, communicate with Visual Basic clients
191
J2EE Connector Architecture (JCA)
• A standard architecture for connecting the J2EE platform to heterogeneous EIS systems– ERP, mainframe transaction processing,
database systems, and legacy applications not written in the Java programming language
– enables the integration of EISs with application servers and enterprise applications • By defining a set of scalable, secure, and
transactional mechanisms
192
• Enables an EIS vendor to provide a standard resource adapter for its EIS
• The resource adapter plugs into an application server, providing connectivity between the EIS, the application server, and the enterprise application
• An EIS vendor needs to provide just one standard resource adapter which has the capability to plug in to any application server that supports the J2EE Connector architecture
193
J2EE Connector Architecture (JCA)
• Multiple resource adapters are pluggable into an application server
• enables application components deployed on the application server to access the underlying EIS systems
194
J2EE Connector Architecture (JCA)
J2EE Connector Architecture
195
Resource Adapter in A.S
• To achieve a standard system-level pluggability between application servers and EISs, the J2EE Connector architecture defines a standard set of system-level contracts between an application server and EIS
• The resource adapter implements the EIS-side of these system-level contracts
196
• System-level software driver used by an application server or an application client to connect to an EIS
• By plugging into an application server, the resource adapter collaborates with the server to provide the underlying mechanisms, the transactions, security, and connection pooling mechanisms
• A resource adapter is used within the address space of the application server
197
Resource Adapter in A.S
Application Contract• An application server and an EIS collaborate to
keep all system-level mechanisms, such as transactions, security, and connection management, transparent from the application components
• A Connection Management contract • A Transaction Management contract • Security contract • A Message Inflow contract • A Lifecycle Management contract • A Work Management contract
198
Web Service Support• Automatically wraps the business components in to
Web services• Support for WSDL and UDDI
– Publish, search, host• Support for Web Services Security standard• Reliable SOAP implementation
– based on a sequence of asynchronous SOAP communications, receipts, and notifications
– guaranteed delivery, “exactly-once ” delivery, ordered conversation
• A set of convenient graphical tools for development, search, and composing of the Web Services– BEA WebLogic Workshop
199
Messaging
• Asynchronous method invocations • Why?
– Performance– Reliability– Support for multiple senders and receivers
Application ApplicationMessage Oriented
Middleware
200
Message Oriented Middleware MOM
• Provides– Guaranteed message delivery– Fault tolerance– Load balancing of destinations– Subscription mech.
• Proprietary solutions– Tibco Rendezvous– IBM MQSeries– BEA Tuxedo/Q – Microsoft MSMQ
201
Java Message Service
• API– Write code to send and receive msg
• Service Provider Interface (SPI)– Plug in JMS drivers
• to allow existing companies to JMS-enable their applications without impacting client-side development
• Supports– Publish/subscribe– Point-to-point
202
203
JMS Connection Factory
JMS Connection
JMS Session
JMS Producer
Or
JMS Consumer
Serialized Message Connection
NamingService
Client
JNDI
4:Lookuo JMS Destination
1:RetrieveJMS Driver Connection Factory
2:Create Connection
3:Create Session
6:Send or Receive Message
5:Create Producer or Consumer
JMS Driver Client Runtime
Java Message Service
Security in A.Servers
• Java Authentication and Authorization Server (JAAS)
• Encryption• Auditing• HTTPS, • basic HTTP authentication with Base64 encoding
for services protected by firewalls• Role based security
– User and group definition– Built-in security data store retains the role,
profile, and entitlement data, and is built on a highly optimized LDAP directory
• Single Sign-On• WS-Security
204
Next Generation Networks NGN
Services Capabilities
205
206
Service Capability Of NGN
207
Service Capability Of NGN
PSTN
App ServerMCU
MRS
SCP iOSS
TG
SoftswitchSoftswitch
Unified Communication
POTS FAXWeb800
OpenEye Video Phone Video Conference
UPT&CRBT
208
PSTN Service
Modem PBX
100 % inherits all PSTN services 100 % inherits all PSTN services
NP
Video conference
Simultaneous Ringing
VAS
Wide Area Centrex
Value added servicesValue added services
Open service system
Flexible & quick service deploymentFlexible & quick service deployment
IP Centrex
Solution for enterprise userSolution for enterprise user
Telephone Fax
INAP CS2 Parlay API
SIP
Service Capability Of NGN
209
Service Capability Of NGN• Inheriting Current Services
– Basic Voice Services– Supplementary Services– Intelligent Network Services
• NGN Value Added Services for Business Users – Basic Services of Centrex– Supplementary Services of Centrex
• Multimedia Application Services
• Value-added Services Integrating Internet
210
• Basic Voice Services– Voice Calls
• between local network users.• Automatic domestic and international direct long distance dialing• Calls from PBX extensions and to PBX console,
– Special services • including different kinds of queries and complaints
– Calls of mobile users in public networks
– Maintenance calls • for operators and maintainers
– Domestic and international fax
Service Capability Of NGN Inheriting Current Services
211
Service Capability Of NGN
Inheriting Current Services − Supplementary Services
Abbreviated dialing Hotline Outgoing call barring Interception service Call forwarding Call back on busy Call waiting Conference calling Quota restricted calling
212
• Intelligent network Services
– Account card calling (ACC)– Free phone (FPH)– Virtual Private Network (VPN) – Televoting (VOT)– Universal personal telecommunications (UPT)– Premium Rate (PRM)– Credit card calling (CCC)– Universal Access Number (UAN)
Service Capability Of NGN Inheriting Current Services
213
Service Capability Of NGN
• Inheriting Current Services – Basic Voice Services– Supplementary Services– Intelligent Network Services
• NGN Value Added Services for Business Users – Basic Services of Centrex– Supplementary Services of Centrex
• Multimedia Application Services
• Value-added Services Integrating Internet
214
• Developed for group users.
• Growing IP customer base
• Provides IP Centrex service for Centrex groups from one Softswitch domain.
• All basic services and supplementary services and a number of new services specialized
Service Capability Of NGN Value added Services for Business Users
215
• Basic Services of Centrex – Intra-group calling out
– Out-group calling out
– Intra-group calling in
– Out-group calling in
– Originating call screening
– Emergency call
– Distinctive ringing
Service Capability Of NGN Value added Services for Business Users
216
• Supplementary Services of Centrex
– Designated pickup
– co-group pickup
– remotely set call forwarding unconditional
– remotely set call forwarding busy and remotely set call forwarding no reply
Service Capability Of NGN Value added Services for Business Users
217
Service Capability Of NGN
• Inheriting Current Services – Basic Voice Services– Supplementary Services– Intelligent Network Services
• NGN Value Added Services for Business Users – Basic Services of Centrex– Supplementary Services of Centrex
• Multimedia Application Services
• Value-added Services Integrating Internet
218
• Electronic whiteboard • Both parties can write and draw on the same
picture, • Remote teaching and technical exchange
• Content release • The contents of advertisements and media streams
can be released through a multimedia terminal • Instant messaging
• Allows real-time communication by means of text between one terminal user and another who has already logged in
Service Capability Of NGN Multimedia Application Services
219
• Video conferencing – Enterprises user may reserve or send a request for a
conference through Web, operator, or conference terminal.
– The Soft Switch or the operator directs MCU for video conferencing
• Video/Streaming/Web – to call or attend a conference at home or office. – The images, voice, slides, text talk, and file can be
sent to each participant synchronously.
Service Capability Of NGN Multimedia Application Services
220
Service Capability Of NGN
• Inheriting Current Services – Basic Voice Services– Supplementary Services– Intelligent Network Services
• NGN Value Added Services for Business Users – Basic Services of Centrex– Supplementary Services of Centrex
• Multimedia Application Services
• Value-added Services Integrating Internet
221
• Click to Dial (CTD)– User sets up a voice or multimedia call through
the VoIP network by clicking a link / number on a Web page.
• Click to Fax (CTF)– User sends a fax to the called subscriber
through the VoIP network by clicking a link/ number on a Web page
Service Capability Of NGN Value Added Services-Integrating Internet
222
• Web 800– User calls the service / subscriber on the IP
network in which bill be paid by the called party. – Subscriber can click the 800 number in a Web page
or dial the 800 number to make a phone call.• UM service
– Combines a variety of media such as Email, Voice Mail, Voice, Video, SM, and Fax
– User receives Email , SM, Fax, Voice Mail and view dynamic images anywhere.
Service Capability Of NGN Value Added Services-Integrating Internet
223
• IM service– Enables the mobile user, online user, and fixed user
to chat through multimedia through mobile, Internet, and fixed messages
– Collaboration allows business users to communicate via voice or text, thus implementing real-time services
• Colouring Ring-Back Tone (CRBT)– System will play back a pre-selected song or record
for the voice caller upon arrival of an incoming call to the callee
Service Capability Of NGN Value Added Services-Integrating Internet
224
Soft PhoneIP Phone
MeetingServer MRS
PSTN/PLMN
PSTN Phone
SIP
Meeting Access No.: +852-28780999
Mobile Phone
Soft switch
Hong Kong
Singapore
UMG
PSTN PhoneIP Phone
UMGPSTN/PLMN
Meeting Access No.: +65-28780999
A meeting can be booked by phone or WEB Instant meeting and scheduled meeting are
provided Meeting service can be sold to group users
Packet network
Powerful tool for conference in NGN era
Service Capability Of NGN Value Added Services-Integrating Internet
225
GUI or Web-based
client
• Intelligent call routing
• Unified message
• Voice mail
• Self-provisioning
Features
• Click to dial
• Click to conference
• Presence
• Address book
Service Capability Of NGN Value Added Services-Integrating Internet
226
H323/SIP video terminal, OPENEYE softphone
Point to point, multi-point video conference which support instant call-
up and booking.
Support interconnect with H323 video network
Business meeting
Parents in hometown
Couples in different
sites
Remote education
OPENEYE SoftwarePC Softphone
Service Capability Of NGN Value Added Services-Integrating Internet
227
INAP
3rd Party APP Server
Parlay API
SG
Soft switch
U-NICAAPP Server
U-NICAParlay Gateway
TELLIN SCP
SIP/INAPSIP/INAP
MRS
SIP
Service Openness Parlay API
Enable to introduce 3rd party service easily and quickly
INAP CS2
Standard IN service interface
Session Initial Protocol (SIP)
Access Application Server by SIP protocol
Open service system– flexible service creating
mode– quick service
deployment– open service interface
Service Capability Of NGN Value Added Services-Integrating Internet
228
Softswitch
App ServerBilling center
iOSS
IP CoreIP Core
Corporate IP bar Resident
UMG
Voice services
Supplementary services
Fax
Internet
PPS
Voice mail
Triple Play
Services by PARLAY
Gateway services etc.
All the services
resident can enjoy.
Immediate
charging
Multi-media call
High speed
internet
Multi-media
configuration
Etc.
IP centrex
IP console
Video Comm.
LAN interconnection
High speed internet
Multi-media conf
One-line-multi-numbers
Service Capability Of NGN Value Added Services
Next Generation Networks
Call Setup
229
Legacy Telephone Service
Basic Service: Call setupPhone number resolution
Call routing
Callee status detection
Resource reservation
Advanced Service: IN features and servicesAuthentication, admission and billing
Call rerouting, redirection, call-back and waiting
In-call application: IVR, call center, voice mail, centrix, and telephone vote
Advanced service provisioning and management based on user’s profile
230
Legacy Network Service Architecture
• Basic service is provided by distributed telephone switches– Call setup is executed in distributed telephone switches– A signaling network (SS7) interconnects the telephone
switches– Call procedures in the switches are interlinked by signaling
(TUP/ISUP)• Advanced service is offered by centralized Intelligent
Network– An advanced service formed by a service logic (SL) and a
serious of service independent blocks (SIB)– A management platform (SMP) supports service creation
and maintenance
231
Legacy Service Architecture
• Separate UNI services and network services• Make services independent of any call processing• Distributed call control and centralized services• One service control point for one service class• One service control point for one service instance• Decompose functions into small pieces and assembly
them together • Authentication, billing and routing are basis of any
services
232
2G MobilePSTN
• The PSTN/ISDN is based on 64 kbit/s digital connections, with a separate “common channel” signalling system• Access may be analogue (telephony), 64 kbit/s
digital (ISDN) or low speed digital (mobiles)• The network establishes an end-to-end digital
connection for the duration of each call• The PSTN/ISDN is designed for high reliability,
specified at the national level and connecting to form a global network
233
Legacy Service Architecture
Legacy Telecom Networks:Layer, Separate, Centralize and Sharing
PhysicalInterface
LogicalInterface
ServiceAccessPoint
Physical NetworkPhysical Network
Transmission NetworkTransmission Network
CPECPE CPECPE
Physical NetworkPhysical Network Physical NetworkPhysical Network
Transmission NetworkTransmission Network
Switching
Network
Switching
Network
Application
Layer
Service
Layer
Transmission
Layer
Physical
Layer
UNI UNI
NNI NNI
NNI
NNI NNI
Switching
Network
Switching
NetworkSwitching
Network
Switching
Network
Service
Network
Service
Network
234
Packet based Communication
• Best effort and service-independent packet-switching
network
• User-driven application/content-independent client-server
mode
• Smart terminal, servers and network
• Transparent active application access
• Open network, open application and open access
• Open and active services on the Internet
235
ISP“The Internet” (best-
endeavours network)
ISP
• The (public) Internet is based on the set of protocols defined by the Internet Engineering Task Force (IETF)• The primary protocol is the Internet Protocol (IP) which
describes a simple connectionless packet protocol able to operate over a range of media
• Other protocols work in association with the IP, for example, TCP to assist reliable end-to-end operation
• The Internet is defined by the Internet protocols rather than by a standardised architecture
• The Internet provides open interfaces, supporting rapid innovation
Packet based - Internet
236
Internet Service Architecture
Transmission
Network
Transmission
Network
Packet
Switching Network
Packet
Switching Network
ISP
Applications
ISP
Applications
CPECPE CPECPE
Transmission
Network
Transmission
NetworkTransmission
Network
Transmission
Network
Packet
Switching Network
Packet
Switching Network
ISP
Applications
ISP
ApplicationsISP
Applications
ISP
Applications
Application
Layer
Network
Layer
Transmission
Layer
PhysicalInterface
LogicalInterface
IP IPIP
NNI NNI
ServiceAccessPoint
APPAPP APPAPPServer Server Server
ServerClient
237
H.323 Architecture
H.323 Zone
H.323Terminal
H.323 Gatekeeper
H.323Gateway
PSTN
H.323Multipoint Control Unit
• Telco-centric multimedia,multiparty conferencing (initially for LANs)• Gatekeeper for network control, heavy-weight protocols• Widely deployed in first wave of VoIP standardization
3 stages of signaling:• RAS to Gatekeeper• H.225 call signaling• H.245 media stream control(can be simplified for VoIP)
238
SIP Based Services
• Internet-centric alternative, initially for large multicast conferences – SIP for call signaling, SDP (Session Description
Protocol) for media • Network servers for additional capabilities:
– Registrar for terminal registration, aliases– Redirect returns contact address directly to end user– Proxy forwards signaling (requests, responses)
• Evolution towards greater use of proxy/registrar for locating users, vertical services, call tracking, network control
239
SIP Call Setup
Shahab Irfan
Ptcl.net.pk ptcl.com
ProxyProxy
DNSLocation
server
Media Streams
INVITE
INVITE
Ringing
Ringing
200 OK
INVITE SDP proposes media type(s), IP & ports to send to
200 OK
200 OK SDP accepts/rejects media, gives IP & ports to send to
ACK
240
Where Do Services Live?
• Some implemented at the endpoints
– Last-number redial, call hold...
• Others may be better supported from the network
– Avoid need for PC or IP phone to be turned on (call forwarding)
– More complex services, such as conferencing
– Integration with web-based services (unified messaging)
• Example: SIP Proxy runs a script for each incoming call
– Parallel forking: forward INVITE to multiple endpoints simultaneously
– Sequential forking: try his office PC first, then lab, then cell phone, …
241
SIMPLE (SIP for IM and Presence)
PeterLinda
ptcl.net.pk ptcl.com
ProxyProxy
Presence server
Linda subscribes to notifications of changes in Peter’s status:Off-line, on-line, busy, away, available, ...
SUBSCRIBE
Update Presence
NOTIFY
NOTIFY
242
• Carrier networks consist of multiple domains
• each domain may have its own policies• each domain may have its own commercial goals• and possibly its own protocols & transport
Carrier Networks are not homogeneous
Domain 3
Domain 2Domain 1
ClientClient
Transport Network Transport Network
Service networkService network
ServiceDomain
ServiceDomain
Relevant interfaces
243
NGN: Service layer on IP, Current Status
• Support of multiple access networks (broadband and narrowband)
• Support of multiple access protocols (H.323, MGCP/MEGACO)
• Support session mobility control (MAP, Mobile IP, HLR/VLR)
• PSTN/IN interworking (ISUP, INAP, CAP, PINT, SPIRIT, SIP-T)
244
Current Approaches of NGN Service Architecture
• Mobile telephone network (GSM, GPRS)– Separation of Home network and serving network– Connection mobility and roaming control
• 3G-UMTS – Service portal and service capability feature (SCF)– Open Service Access (OSA)
• SIP– Distributed service control – Open access to services and applications
• Web Service (SOAP/WSFL/WSDL/UDDI)– Service access portal (SOAP)– Service description, discovery, and integration (UDDI)
245
ATerminal
ATerminal
B Terminal
B Terminal
APortal
BPortal
TransmissionTransmissionAccessAccess AccessAccess
Session ServiceSession Service
Control ServiceControl Service
A Home ServiceA Home Service B Home ServiceB Home ServiceA User Service Management
A User Service Management
B User ServiceManagement
B User ServiceManagement
TransmissionTransmissionAccess ServiceAccess Service Access ServiceAccess Service
TerminalTerminal TerminalTerminalTelecom basic service/call controlTelecom basic service/call control
Off-line customer managementOff-line customer management
Extended call control and IN chargingExtended call control and IN charging
Linear Service Architecture in Legacy Network: Static Services
Two-Dimension Service Architecture in NGN: Active Services
Changes of Telecom Service Architecture
246
NGN Soft switch: Services
• Legacy telephone service is static and close• Current soft switch experiences legacy
service architecture• Soft switch session is going to be distributed• Telecom service is becoming with 2-D
dynamic• Home service portal is to support open
service access• Service broker provides a platform for open
services
247
NGN Services Characteristics
• Multiple numbering systems • IP, Phone, Universal Numbers
• Distributed Intelligence• Databases in central servers, Provider database,
Customer PC, Phones• Central global database does inter-provider
translation
• Central Database is ‘shared’ by providers• Transaction volume
• At central db, number of inter-provider calls• At services databases (800, call-blocking lists, …)
number of subscribed services• At Provider and endpoints
248
NGN Services Characteristics cont’d
• Network Repositories • User data (profiles, lists) in multiple devices and
databases• Central Server provides reliability• Updates to devices synchronized on re-connect • Synchronization on demand or periodically:• User mobility
• Where should translation take place• Should cache migrate• Real-time constraints
• Transaction volume across devices, endpoints...
249
NGN Services Characteristics
• Object based services– Calls abstracted as object– Call models implemented within objects– Object mobility used to implement services
• Call forwarding• Third party call set-up
• Objects for service creation– Tool-kit for third party service creation– Base Objects/components upon which to build
• Device Independence– Migrate calls across device– Compose services across devices
250
End-to-End Connectivity?
There is no shortage of possible approaches – and they are all in use!
The problem– How to guarantee end-to-end service with the required QoS
across multiple networks using incompatible implementations[the subject of current international work]
251
Expected NGN Scope and Service Scope
252
Today’s Network Architectures
• Multiple, interworked, interdependent networks• Diversity of control and management architectures• Capacity and performance bottlenecks• Each network has its own control plane and management plane
• Multiple, interworked, interdependent networks• Diversity of control and management architectures• Capacity and performance bottlenecks• Each network has its own control plane and management plane
IP/MPLSNetworks
PSTN/ISDN
Radio Access
Networks
EthernetNetworks
Wireless Access
Frame Relay
Networks
IWF
IWF
IWF
IWF
IWF
IWF
IWF
ATM Networks
IWF
IWF
253
Near Term Evolution
ATM Networks
IWF
PSTN/ISDN Rec. Q.2931, PNNI
Frame Relay
Networks
IP-based Networks
PSTN/ISDN OSF & NM, M series Rec.
Rec. Y.1310
IETF RFCs
Q & X series Rec.
IWF
IWF
Rec. I.555Rec. I.580
Rec. Q.931
ATM OSF & NM, M series Rec.
SNMP based
FR OSF & NM
OSF = Operating Support Function
For• Convergence on ATM core networking enables initial stage
of unified management and control• Enhanced performance and QoS capabilities for multi-
services over common platform
For• Convergence on ATM core networking enables initial stage
of unified management and control• Enhanced performance and QoS capabilities for multi-
services over common platform
PSTN/ISDN
IWF
SS7 Network
Rec. I.580Rec. Q.700 series
Against• Lack of service transparency between IP
based services and ATM/PSTN services
Against• Lack of service transparency between IP
based services and ATM/PSTN services
Wireless access
IWF
254
Full-term - Convergence on IP/MPLS Core
• Requires well defined interworking mechanism for all services• Transfer plane functions• Control plane functions• Management plane functions
• Requires well defined interworking mechanism for all services• Transfer plane functions• Control plane functions• Management plane functions
IP/MPLS NETWORK
ATMNetworks
Frame Relay
Networks
Frame Relay
Networks
IWF EthernetNetworks
EthernetNetworks
ATM Networks
Label Switching Router (LSR) Label Switched Path (LSP)
IWF IWF
IWF
IWFIWF
255
Recommended practical/lab work on NGN
256
• To connect different Media Gateways like IAD, AGW, MGW, UMG etc with subscriber end
• To configure different MGWs mentioned above with IP core network by using basic commands
• To test the Network connectivity and to identify the fault points on the Network by using commands like ping, tracert etc
• To learn creation of a terminal user and querying the existing user and displaying other terminals
• Learning the addition and removal of particular board/frame of media gateways by using basic commands of Board Management/Frame Management etc
• Adding and removing the IP address of a particular interface on a particular board
257
Recommended practical/lab work on NGN