cs2000PDISN07.07.03

International Succession Networks

CS2000 International Product DescriptionCommunication Server Capabilities for International Markets

Issue ISN07_v3 (approved), 17 August 2004

PrefaceThe ISN07 Product This document is a CS2000 Product Description for ISN07. The name ISN07 denotes a set of ISN (International Succession Networks) software loads installed on Communication Server 2000 hardware platforms. CS2000 belongs to the Nortel Networks portfolio of Succession Networks products. It provides call handling capabilities for use with packet-based IP (Internet Protocol) and ATM (Asynchronous Transfer Mode) media networks. These capabilities include a wide range of internationally proven call processing agents, translations, routing, billing and services software. Specific applications currently supported over packet bearer networks are VoIP (Voice over IP) and VoATM (Voice over ATM). ISN07 support for these applications is made available to customers via Nortel-defined network solutions: VoIP The PToIP (Packet Trunking over IP), IAW (Integrated Access Wireline) and IAC (Integrated Access Cable) solutions are based on an IP backbone network. Note: The IP backbone network can be implemented in a number of different ways, depending on the requirements and preferences of the network operator. These include VoIP with MPLS at Layer 2 and VoIP over ATM using AAL5. See the separate document IP Networks for Succession for further information. The VToATM (Voice Trunking over ATM) solution is based on an ATM backbone network with AAL2 (ATM Adaptation Layer 2) bearer connections.

VoATM

ISN software can also be installed on the DMS-100 hardware platform to provide circuit-based switching and service support capabilities, in which case it is referred to as ISN (TDM). ISN software can even be installed in a hybrid configuration that comprises CS2000-specific and DMS-specific hardware as well as hardware that is common to both. Such a hybrid configuration can support circuit-based and packet-based capabilities simultaneously, using looparound trunks to support call interworking between the circuit and packet environments. Development of a software load that can support both packet-based and circuit-based capabilities is central to Nortels Succession Networks strategy. This strategy is based on maximum re-use of proven telephony software combined with maximum exploitation of leading-edge hardware and network architecture. It means that the same range of proven call-processing agents, translations and routing capabilities and value-added services isIssue ISN07_v3 (approved) 17 August 2004 PROPRIETARY Page

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CS2000 International Product Description

potentially available to any network operator regardless of backbone network type, and that there is an easy migration path to a packet-based next-generation network architecture. The aim is to realise the Nortel Networks vision of Unified Networks that can convey voice, data and multimedia traffic with equal ease. Document Purpose and Structure The aim of this Product Description is to provide a high-level functional view of the complete portfolio of ISN07 capabilities. It describes the superset of all capabilities that are formally supported and available for deployment, not the subset of capabilities deployed by any one network operator. The document serves as a single source of high-level product information about the ISN07 capabilities available for deployment in international markets. It is intended for internal use and for controlled external distribution to Nortel Networks customers. Within Nortel, it can be used as a baseline for product planning, as a checklist for integration and testing, and as a reliable summary of capabilities for the use of business units. Externally, it provides a basis for discussions between Nortel and its customers about how they can best take advantage of the capabilities described. The document comprises the following parts, each of which is further divided into chapters that provide more detailed information: ! ! ! ! ! ! ! ! Part A: Part B: Part C: Part D: Part E: Part F: Part G: Part H: Introduction Hardware Software Packet Telephony Protocols TDM Telephony Interfaces Features and Services Network Fit OAM&P

See the ISN07 Release Contents appendix on page 843 for information about the delta between ISN07 and the previous ISN05 release. Relationship with Other Documents As explained on the previous page, ISN software can support both packet-based and circuit-based capabilities, and (in a hybrid configuration) can even support them simultaneously. This Product Description provides detailed descriptions only of CS2000 components and of DMS hardware components that are common to DMS and CS2000 and may be included in a non-hybrid CS2000 configuration. For a systematic description of all DMS hardware, including components for which hybrid configuration interworking is supported, refer to the separate ISN07 (TDM) Product Description. This Product Description is intended to complement the FCAPS documents that provide detailed reference information about service configuration and datafill, not to replace them. Specifically, its functional view of ISN07 capabilities is intended to provide a context within which implementation details are easier to understand.

Issue ISN07_v3 (approved) 17 August 2004

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Table of Contents

Part A OverviewChapter A1 Chapter A2 Market Overview Network Overview A2.1 MEGACO Network Architecture A2.2 CS2000 Implementation of MEGACO Architecture A2.3 CS2000 Support for Network Architecture A2.3.1 Hardware Support A2.3.2 Software Support A2.4 The Backbone Packet Network A2.4.1 Network Characteristics A2.4.2 PSTN Equivalence for Packet Networks Product Overview A3.1 Configurations Available A3.2 Capacity A3.3 Telephony Interfaces Supported A3.4 Interworkings between Telephony Interfaces 2 3 3 5 7 7 13 19 19 19 21 21 22 22 25

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Part B HardwareChapter B1 CS2000 Hardware B1.1 Overview B1.2 Processor Complex (Core) B1.2.1 XA-Core B1.2.2 Processor Complex for CS2000-Compact B1.3 Internal Communication (CS LAN and MS) B1.4 Gateway Controllers (GWCs) B1.5 Session Server B1.6 CCS7 Signalling Terminations B1.6.1 USP (Universal Signalling Point) B1.6.2 FLPP Signalling Peripheral B1.7 OAM&P Hardware B1.8 CS2000 Interworking with Legacy Peripherals B1.8.1 Hybrid Configurations using Looparound Trunks B1.8.2 Hybrid Configurations using the IW-SPM B1.9 Hardware Packaging B1.9.1 CS2000 Cabinets B1.9.2 Typical Cabinet Lineups CS2000 Support for Media Gateways B2.1 Introduction B2.2 Categorising Media Gateway Capabilities B2.3 PVG (Packet Voice Gateway) Trunk Gateways B2.4 PVG as a V5.2 Gateway B2.5 H.323 Gateways B2.6 Mediant 2000 Trunk Gateway B2.7 Westell DPNSS Gateway B2.8 Carrier-Located Line Media Gateways B2.9 Line Media Gateways on Customer LANs B2.10 Line Media Gateways on Cable Access Networks B2.11 CVX1800 Media Gateway for RAS CS2000 Support for Media Servers B3.1 Introduction B3.2 AudioCodes MS2000 Series (MS2010 / MS2020) B3.3 Universal Audio Server (UAS) CentrexIP Remote Clients and the CentrexIP Client Manager B4.1 Network Configuration for CentrexIP Client Access B4.2 CentrexIP Clients and their Capabilities B4.3 CentrexIP Client Manager (CICM) 29 30 34 34 38 42 53 71 72 73 78 81 89 89 90 93 93 94 96 96 98 99 111 115 116 118 119 123 126 130 133 133 135 138 144 144 146 149

Chapter B2

Chapter B3

Chapter B4


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Chapter B5

Media Proxies B5.1 Media Proxy Functions B5.1.1 Network Address Translation (NAT) B5.1.2 NAT Traversal B5.2 RTP Media Portal Multimedia Communication Server (MCS52000) B6.1 Network Role of MCS5200 B6.2 MCS5200 Components B6.3 MCS5200 Connectivity B6.4 CS2000 / MCS5200 Combined Configuration

153 153 153 154 156 165 165 166 169 170

Chapter B6

Part C SoftwareChapter C1 Software Loads C1.1 CS2000 Core Load C1.2 Loads for Other CS2000 Components C1.3 Loads for Media Gateways and Servers C1.4 OAM&P Software Trunk and Line Datafill C2.1 The Purpose of Datafill C2.2 Trunk Group Provisioning C2.3 Signalling Link Provisioning C2.4 Provisioning GWC Units C2.5 Provisioning Gateways, Carriers and Trunk Endpoints C2.6 Provisioning Inter-CS Trunks C2.7 Provisioning Lines C2.8 Provisioning Gateways and Line Endpoints C2.9 Provisioning Tones and Announcements Translations and Routing C3.1 Overview C3.2 NCOS Screening C3.3 IBN Translations C3.4 Indirect Access to Universal Translations C3.5 Universal Translations C3.6 Codec Selection via Translations C3.7 Routing C3.7.1 Line Routing and Selection C3.7.2 Trunk Routing and Selection C3.7.3 Routing to Treatment C3.8 Support for CCD (Clear Channel Data) Calls C3.9 Order Codes for Translations and Routing Software 172 173 176 178 179 182 182 183 185 189 190 191 196 200 203 204 205 206 207 209 210 216 218 218 219 227 229 229

Chapter C2

Chapter C3

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Part D Packet Telephony ProtocolsChapter D1 Overview of Packet Telephony Protocols 231 D1.1 Packet Network Protocol Stacks 233 D1.2 Transport Protocols 234 D1.2.1 UDP (User Datagram Protocol) 234 D1.2.2 TCP (Transaction Control Protocol) 234 D1.2.3 SCTP (Stream Control Transmission Protocol) 235 D1.2.4 RUDP (Reliable UDP) 238 D1.3 Session Descriptions (SDP) 239 SIP and SIP-T H.248 ASPEN H.323 UniStim NCS MGCP MPCP IUA V5UA MTP Adaptation Protocols (M3UA and M2PA) DSM-CC OAM&P Protocols D14.1 SNMP (Simple Network Management Protocol) D14.2 Configuration Protocols (BOOTP, DHCP, TFTP) 243 256 280 288 300 308 319 325 329 332 338 342 347 348 352

Chapter D2 Chapter D3 Chapter D4 Chapter D5 Chapter D6 Chapter D7 Chapter D8 Chapter D9 Chapter D10 Chapter D11 Chapter D12 Chapter D13 Chapter D14


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Part E Telephony InterfacesChapter E1 Overview of Support for Telephony Interfaces E1.1 CCS7 Trunk Interfaces E1.2 Intelligent Network Interfaces E1.3 Access Interfaces E1.4 VPN Interfaces E1.5 Basic Analogue Subscriber Line Interfaces E1.6 CentrexIP Lines E1.7 Interworking in a Packet Network Environment CCS7 Interfaces E2.1 Introduction E2.2 TDM and Packet Network Implementations of CCS7 E2.3 ISDN User Part (ISUP) Support E2.3.1 Overview E2.3.2 ISUP Standards and Variants E2.3.3 CS2000 Support for ETSI / ITU ISUP E2.3.4 CS2000 Support for ANSI ISUP Variants E2.3.5 UK ISUP Support E2.3.6 SPIROU (French ISUP) Support E2.3.7 Interworking Support for ISUP Variants E2.3.8 Software Order Codes for ISUP E2.4 Telephony User Part (TUP) Support E2.4.1 IUP / BTUP Support E2.4.2 SSUTR2 / FTUP Support E2.4.3 CTUP Support E2.4.4 Software Order Codes for TUP E2.5 MTP, SCCP and TCAP Support INAP E3.1 357 358 360 361 362 363 363 364 368 368 371 381 381 382 386 395 398 400 401 405 406 406 410 413 415 416 422 422 422 423 424 426 430 430 438 441 442 444 444 445 445 450 455 460

Chapter E2

Chapter E3

E3.2

E3.3 E3.4 E3.5 Chapter E4

Functional Description E3.1.1 IN Functional Elements E3.1.2 INAP Specifications E3.1.3 Peer-to-Peer Communication using INAP E3.1.4 Interaction between Call Processing and IN CS2000 Implementation E3.2.1 INAP Operation Support E3.2.2 Detection Point Support E3.2.3 Support for Application Context Negotiation INAP Signalling Interworkings Overview of Feature Set Support Order Codes for INAP

PRI Access Interface E4.1 Functional Description E4.2 CS2000 Implementation E4.3 Capabilities Supported E4.4 Limitations

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E4.5 E4.6 Chapter E5

Overview of Feature Set Support Order Codes for PRI

460 460 461 461 474 482 482 482 483 483 485 489 490 490 491 491 493 497 499 507 507 507 508 508 509 512

QSIG VPN Interface E5.1 Functional Description E5.2 CS2000 Implementation E5.3 Limitations E5.4 Overview of Feature Set Support E5.5 Order Codes for QSIG DPNSS Interface E6.1 Functional Description E6.2 CS2000 Implementation E6.3 Order Codes for DPNSS IBN Lines E7.1 Functional Description E7.2 CS2000 Implementation E7.2.1 Lines off Large Carrier-Located Gateways E7.2.2 Cable Lines off MTA Gateways E7.2.3 Customer LAN Lines E7.2.4 V5.2 PSTN Lines E7.3 Line Provisioning E7.4 Overview of Feature Set Support E7.5 Order Codes for Analogue Lines CentrexIP Lines E8.1 Functional Description E8.2 CentrexIP Clients and their Capabilities E8.3 Network Configuration for CentrexIP Client Access

Chapter E6

Chapter E7

Chapter E8

Part F Features and ServicesChapter F1 Feature Support Overview F1.1 Feature Sets Currently Supported F1.2 Feature Support in a Packet Network Environment Analogue Subscriber Line Services F2.1 Introduction F2.1.1 Assigning Services to Lines F2.1.2 Service Packaging F2.2 Service Categories and Services Available F2.2.1 Call Barring and Restrictions F2.2.2 Speed Calling Services F2.2.3 Call Forward Services F2.2.4 Call Handling F2.2.5 Hunt GroupsPROPRIETARY

515 515 518 530 530 530 531 532 532 533 533 535 536Page

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F2.3 F2.4 F2.5 F2.6 Chapter F3

F2.2.6 Uniform Call Distribution (UCD) F2.2.7 Automatic Call Distribution (ACD) F2.2.8 Voice Mail F2.2.9 Party Information Services F2.2.10 Data Download F2.2.11 Screening Services F2.2.12 Call Completion / Call Return F2.2.13 Regulatory Services F2.2.14 Miscellaneous Services CEPT Services and the CEPT Line Option Service Availability with Different Line Types Service Support on Interworking Order Codes for Analogue Line Services

536 537 542 543 545 546 547 548 549 550 552 556 556 558 558 559 560 565 565 566 567 574 575 576 577 577 578 578 578 579 582 582 582 583 584 585 585

Feature Support for CentrexIP Clients F3.1 Feature Categories Supported F3.2 Feature Assignment and Activation for CentrexIP Clients F3.3 Features and Options Supported ISDN Supplementary Services F4.1 Introduction F4.2 MoU1 Service Support F4.3 MoU2 Service Support F4.4 Non-ETSI ISDN Services F4.5 Networked Support for Supplementary Services F4.6 Order Codes for ISDN Supplementary Services QSIG Services F5.1 Overview F5.2 Features Supported as Part of QSIG Basic Call F5.3 QSIG Additional Network Features F5.3.1 Transit Counter F5.4 VPN Support via QSIG Feature Transparency (QFT) F5.5 ISDN Supplementary Services F5.5.1 Connected Party Number (COLP/COLR) F5.5.2 Advice of Charge (AOC) F5.5.3 Call Completion (CCBS / CCNR) F5.6 German Network Features F5.7 Service Support on Interworking F5.8 Order Codes for QSIG Services

Chapter F4

Chapter F5

Chapter F6

DPNSS Features 586 F6.1 Functional Description 586 F6.2 DPNSS Feature Support Mechanisms 594 F6.2.1 Direct Support 594 F6.2.2 Support via DPNSS Feature Transparency (DFT)594 F6.3 DPNSS / Centrex Feature Interactions 596 F6.4 Order Codes for DPNSS Services 597

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Chapter F7

APM Feature Transparency F7.1 Overview F7.2 Application Contexts Supported by CS2000 F7.2.1 Services Supported via APM AC 1 (PSS1) F7.2.2 Services Supported via APM AC 3 (AOC) F7.2.3 Services Supported via APM AC 124 (Nortel) VPN F8.1 F8.2

598 598 600 600 602 603 605 605 605 606 607 607 608 609 611 612 612 615 621 622 623 624 624 626 626 626 627 628 628 629 630 630 631 631 632 635 636 640 643 644 649 650 651

Chapter F8

F8.3

F8.4 F8.5 Chapter F9

Introduction F8.1.1 VPN Infrastructure Options and Benefits F8.1.2 VPN Access Options and Benefits VPN Telephony Overview F8.2.1 VPN Functional Elements F8.2.2 VPN Call Types F8.2.3 VPN Services F8.2.4 Flexible Translations and Routing Protocols Used for VPN F8.3.1 Access Signalling Support F8.3.2 Network Signalling Support F8.3.3 Trunk and Access Signalling Options Interaction with MCS5200 to Support VPN Order Codes for VPN

Voice Mail F9.1 Overview F9.2 Voice Mail Interfaces F9.2.1 Message Desk Interface F9.2.2 Subscriber Interface F9.4 Order Codes for Voice Mail Conferencing F10.1 Overview F10.2 Network Configuration for Conferencing F10.3 Using Conferencing Capabilities F10.4 Order Codes for Conference Services Indirect Access F11.1 The Purpose of Indirect Access F11.2 Call Completion Scenarios F11.3 Different Types of Indirect Access F11.3.1 CLI Checking via Table DNSCRN F11.3.2 Authcode Checking via Table AUTHCDE F11.4 Supporting Interfaces and Call Flows F11.4.1 Call Flows for CLI-Based Indirect Access F11.4.2 Call Flow for Authcode Access F11.5 Indirect Access Billing F11.6 Order Codes for Indirect Access

Chapter F10

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Chapter F12

IN Services F12.1 Introduction F12.2 Service Support Capabilities F12.3 Creating and Deploying Services F12.4 Interaction between IN and Non-IN Features F12.5 Order Codes for IN Services

652 652 653 656 657 659

Chapter F13

Providing Call Party Information (CLI and Related Services) 660 F13.1 Terminology and Basic Concepts 661 F13.2 Party Information Services 664 F13.3 Functional Overviews 666 F13.4 Parameters for Conveying Party Information 670 F13.5 Delivery of Party Information for Display 680 F13.6 CS2000 Provisioning 682 F13.7 Per-Interface Summary of Capabilities 686 Regulatory Services F14.1 Special Call Types F14.1.1 Emergency Calls F14.1.2 Priority Calls F14.2 Call Tracking and Supervision Features F14.2.1 Malicious Call Identification (MCID) F14.2.2 Lawful Interception (LI) F14.3 Charging and Billing Features F14.3.1 Network Advice of Charge (NAOC) F14.3.2 Payment Ceiling for Analogue Lines (PCA) F14.3.3 Notification of Time and Charge (NTC) F14.4 Network Interconnect Features F14.4.1 Basic Interconnect F14.4.2 Indirect Access F14.4.3 Carrier Selection F14.4.4 Carrier Name Notification (CNN) F14.4.5 Account Code (ACCT) F14.4.6 Number Portability F14.5 Miscellaneous Features F14.5.1 Call Forward Restrictions for Hong Kong F14.6 Order Codes for Regulatory Services Multimedia Services for Blended Users F15.1 Introduction F15.2 CS2000 Blended User Configuration F15.3 Call Setup Sequences F15.4 Specific Services Supported ADSL Data Sessions RAS (Remote Access Service) F17.1 Overview F17.2 Virtual Points of Presence (VPOPs) 693 694 694 696 697 697 699 703 703 704 705 706 706 706 706 706 706 707 711 711 711 712 712 713 715 718 719 720 720 722

Chapter F14

Chapter F15

Chapter F16 Chapter F17

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Part G Network FitChapter G1 Numbering Plan G1.1 Public Numbering Plan G1.1.1 Support for Geographic Numbers G1.1.2 Non-Geographic Numbers and Services G1.1.3 International Calls G1.1.4 CS2000 Inpulsing/Outpulsing Capacity G1.1.5 Number Portability G1.1.6 ODP and Services G1.1.7 Order Codes for Open Dial Plan Support G1.2 Private Numbering Plans CS2000 Support for Tones G2.1 Overview G2.2 Classifying and Identifying Tones G2.3 CS2000 Implementation G2.3.1 Identifying Tones G2.3.2 Requesting the Playing of a Tone G2.4 Media Gateway Support for Tones CS2000 Support for Announcements G3.1 Announcement Characteristics G3.2 The Role of the MS2000/UAS Media Server G3.3 GWC - Media Server Communication via H.248 G3.4 Announcement Capacity G3.5 Announcement Datafill G3.6 The Audio Provisioning Server (APS) 724 724 724 726 726 727 727 728 730 731 733 734 735 738 738 738 739 742 743 744 745 746 746 747

Chapter G2

Chapter G3

Chapter G4

Network Integration Issues 748 G4.1 CS2000 Solutions 748 G4.2 International Deployment Considerations 749 G4.2.1 International Gateway Functionality 749 G4.2.2 Support for Multiple Timezones 750 G4.2.3 MCCS (Multi-Country Call Server) Capability 750 G4.3 Bearer Capability Mapping 751 G4.3.1 End-to-End Codec Negotiation 751 G4.3.2 Codec Negotiation via Translations 752 G4.3.3 RFC2833, T.38 and Comfort Noise (CN) 753 G4.4 Packet / Circuit Interworking 754 G4.4.1 Echo Cancellation 754 G4.4.2 Continuity Testing 755 IP Addressing and Internet Transparency G5.1 Public and Private IP Addresses G5.2 Communication between Address Domains G5.3 Network Address and Port Translation G5.4 NAT Traversal 756 756 757 759 760

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G5.5 Chapter G6

IP Addressing Example for CS2000 Solutions

762 764 764 765 765 767 767

CAC (Call Admission Control) G6.1 The Need for Call Admission Control G6.2 CS2000 Support for Virtual Call Admission Control G6.2.1 Logical Network Model G6.2.2 GWC Support for LBL Traversal and VCAC G6.3 Order Codes for VCAC

Part H OAM&PChapter H1 Overview of OAM&P for CS2000 Solutions H1.1 Logical OAM&P Architecture H1.1.1 The TMN Hierarchy H1.1.2 EMs and Management Applications Supported H1.2 Physical OAM&P Architecture H1.2.1 Trusted Access to NEs via the OAM&P VLAN H1.2.2 External cccess to the OAM&P VLAN H1.2.3 Software Packaging for EMs and Applications H1.3 Access to EMs and Management Applications H1.3.1 IEMS H1.3.2 User Access to IEMS, EMs and Applications Fault Management H2.1 Summary of Fault Management Capabilities H2.2 Alarm Reporting H2.3 Fault Reporting via Logs H2.4 Other Fault Reporting Mechanisms H2.5 Fault Isolation and Correction (Maintenance) Configuration H3.1 Summary of Configuration Capabilities H3.1.1 Commissioning H3.1.2 Service Activation H3.2 Hardware Commissioning H3.3 Trunk Provisioning H3.4 Line Provisioning H3.5 V5.2 Provisioning H3.6 Connections to Provisioning Applications Accounting H4.1 Summary of Accounting Capabilities H4.2 CS2000 Core Support for Billing H4.2.1 Call Recording Formats Supported H4.2.2 Automatic Message Accounting (AMA) H4.2.3 Station Message Detail Recording (SMDR) H4.2.4 Creation and Transfer of Billing Records H4.2.5 Controlling the Generation of Billing RecordsPROPRIETARY

769 770 770 771 774 774 776 777 782 782 783 784 784 788 789 793 794 795 795 795 796 798 799 800 801 802 803 803 804 804 805 819 819 820

Chapter H2

Chapter H3

Chapter H4

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H4.3

H4.2.6 Metering / Advice Of Charge (AOC) H4.2.7 Order Codes for Accounting Support Core Manager SBA Support for Billing H4.3.1 Overview H4.3.2 Closing Billing Files Ready for Transfer H4.3.3 File Transfer Options H4.3.4 File Transfer Performance H4.3.5 AMA Search via AMADUMP

821 822 823 823 824 824 825 825 826 826 830 835 836 837 838 838 840 841

Chapter H5

Performance Management H5.1 Summary of Performance Monitoring Capabilities H5.2 Performance Monitoring via OMs H5.3 Performance Monitoring via PMs H5.4 QoS Monitoring Security (OAM&P Access Control) H6.1 Network Architecture for Security H6.2 Security Overview H6.3 User Authentication and Account Administration H6.4 Secure Remote Access

Chapter H6

AppendicesAppendix A ISN07 Release Contents A.1 Overview A.2 Hardware A.3 Software A.4 Packet Telephony Protocols A.5 Telephony Interfaces A.6 Features and Services A.7 Network Fit A.8 OAM&P Summary of Product Description Updates for ISN07 References C.1 Nortel Interface Specifications C.2 Standards C.3 Nortel Design Documents (FNs) 843 844 844 849 849 852 856 862 864 871 877 877 878 881

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Abbreviations3PC 3WC AC ACRJ AAL AAL2 AAL5 ACIF ADSL AISUP A-law AMA ANF ANSI AO AOC API APM APS AR ARDDN ARP ASN ASPEN ATA ATM AUL AVT AXU BCP BCT BDF BHCA BICC BML BNS Third-Party Core (Motorola N765 processors used by CS2000-Compact) Three-Way Call (line service) Audio Controller (GWC for UAS) Anonymous Call Rejection (line service) ATM Adaptation Layer ATM Adaptation Layer for VBR real-time traffic; can be used for voice ATM Adaptation Layer for lightweight VBR data traffic (also called SEAL) Australian Communication Industry Forum (standards body) Asymmetrical Digital Subscriber Line Australian ISUP (IBN7-based agent used to support Malaysian ISUP V1) International PCM standard used for speech path encoding/companding Automatic Message Accounting (for billing calls) Additional Network Feature (type of QSIG service) American National Standards Institute Alternative Operator (competing with an established PTT) Advice Of Charge (ISDN service) Application Program Interface (for standard calls to software functionality) Application Transport Mechanism (for feature transparency) Audio Provisioning Server (for UAS provisioning) Automatic Recall Automatic Recall of Diallable Directory Number Address Resolution Protocol (finding the Ethernet address for an IP address) Abstract Syntax Notation Proprietary device control protocol used to control PVG media gateways ASCII Terminal Access (OAM&P application) Asynchronous Transfer Mode Automatic Line (line service) Audio / Video Transport (IETF working group) Alarm Cross-Connect Unit (connectivity for optional OAU) Best Common Practice Bearer Channel Tandeming (for LI) Binary Distribution Format Busy Hour Call Attempts Bearer Independent Connection Control (ISUP with packet extensions) Buriness Management Layer (in TMN hierarchy) Billing to the Nearest Second (for NAOC)PROPRIETARY Page


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BOOTP BSL CAC CBM CBR CC CCB CCBS CCD CCF CCF CCITT CCS7 CCW CDP CEM CES CFB CFD CFDVT CFNA CFNR CFU CG4500E CGP CHD CIC CIC CICM CID CLASS CIEC CLF CLI CLLI CLUI CM CMT CMTS CNAB CNAMD CND CNDB CO LAN COPS CORBA cPCI CPE CPS CR CRCX CRR CRR

Bootstrap Protocol Bar-Separated Log Connection Admission Control Core and Billing Manager (successor / alternative to SDM) Constant Bit Rate Call Control CEPT Call Back (implemented via AR) Call Completion to Busy Subscriber Clear Channel Data (as used for ISDN data calls) Call Control Function (call processing model used for IN) Call Control Frame (PTE2000 housing CS2000-Compact Core) Consultative Committee for International Telephone / Telegraph (now ITU) Common Channel Signalling System No. 7 (also called SS7) Cancel Call Waiting (line service) Charge Determination Point (for NAOC) Common Equipment Module (IW-SPM controller card) Circuit Emulation Service Call Forward on Busy (line service) Call Forward on DoesntAnswer (line service) Call Forward on DoesntAnswer with Variable Timer (line service) Call Forward on No Answer (see CFD) Call Forward on No Reply (see CFD) Call Forward Unconditional (line service) Hardware platform for MTA line gateway Charge Generation Point (for NAOC) Call Hold (line service) Carrier Identification Code (as used in IA carrier selection) Circuit Identification Code (in MTP routing label) CentrexIP Client Manager Correlation ID Custom Local Area Signalling Services Chosen Intermediate Exchange Carrier Calling Line Flash (MCID) Calling Line Identification (caller number) Common Local Language Identifier (identifying trunk destination) Command Line User Interface Computing Module (alternative name for XA-Core or Compact 3PC) CS2000 Management Tools Cable Modem Termination System Calling Name Delivery Blocking (line service) Calling Name Delivery (line service) Calling Number Delivery (line service, 10-digit CLIs only) Calling Number Delivery Blocking (line service) Central Office LAN (name previously used for CS LAN) Common Open Policy Service (GWC - CMTS signalling for CAC) Common Object Request Broker Architecture (as used by PMSS) Compact Personal Computer Interface Customer Premises Equipment Carrier Pre-Selection (as used in indirect access) Centralised Replicator (used to implement LI BCT for packet network calls) Create Connection (ASPEN message) Conditional Re-Routing (of ISUP call if congestion is encountered) Call Retrieval Request (for voice mail)

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CSP CS CS CS LAN CS2000 CS2E CS2M CSP CSV CUG CWT CXR DCE DCOS DCP DDMS DDN DHCP DLCX DM DMC DMZ DNS DN DOCSIS DOR DPNSS DPT DQoS DS DSLAM DSM-CC DSS1 DSP DTC DTD DTM DTMF

Communication Services Platform (CS2000 Base / Telecom layer software) Call server (alternative name for Communication Server) Comunication Server Communication Server LAN (as used to connect CS2000 components) Nortel Networks Communication Server described in this document SDM software load supporting CS2000 Core Manager CS2000 Management Tools (Sun server load supporting EMs) Carrier Selection Parameter (for inter-network use) Comma-Separated Values (format for data file) Closed User Group Call Waiting (line service) Call Transfer (line service) Distributed Computing Environment Data Collection Operations System (passive collection of performance OMs) Device Control Protocol DMS Data Management System (OAM&P application) Delivery of Diallable Number (line service) Dynamic Host Configuration Protocol Delete Connection (ASPEN message) Domain Management Device / Media Control (signalling between GWC and gateway) Demilitarised Zone (network supporting public address domain) Domain Name Server Directory Number Data Over Cable System Interface Specification (CMTS - MTA signalling) Denied Origination (outgoing call barring) Digital Private Network Signalling System Dynamic Packet Trunk (for inter-CS communication via SIP-T or BICC) Dynamic Quality of Service Data Store (XA-Core memory used to store customer data) Digital Subscriber Line Access Multiplexer Digital Storage Media Command and Control (protocol used for RAS) Digital Signalling System No1 (Q.931) Digital Signal Processor Digital Trunk Controller Document Type Definition (for XML file) Denied Termination (incoming call barring) Dual-Tone Multi-Frequency (tones used in dialling)

E1 2Mb/s PCM30 carrier (international TDM standard) EADAS Engineering and Administrative Data Aquisition System (early DCOS) EBIP Electrical Breaker Interface Panel EID Endpoint Identifier (for a particular channel on a particular E1 at a gateway) EIOP XA-Core IOP equipped with Ethernet packlet (now superseded by HIOP) ELN Essential Line EM Element Manager (for an NE) EML Element Manager Layer EMS Element Management System (OAM&P server type or application) ESA Emergency Stand-Alone ETA Enhanced Terminal Access (OAM&P application) ETSI European Telecommunications Standards Institute EuroDOCSIS DOCSIS standard defined for use in Europe


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FCM FLPP FP FQDN FSM G.703 G.711 G.726 G.729 GARP GEM GigE GoS GUI GW GWC H.248 H.323 HFC HIOP HLM IA IAC IAD IAM IAW IBL IBN IBN7 ICE ID IE IEC IEMS IETF I-ISUP IMS IN INAP IOM IOP IP IP IPSP ISDN ISM ISN ISN07 ISP ISUP

Fabric Control Message (used to co-ordinate GWCs) Fiberised Link Peripheral Processor (SG terminating CCS7 signalling links) Function Processor Fully Qualified Domain Name (identifies an IP network host) Finite State Machine ITU-T standard for PCM30 interface (E1 carriers) ITU-T standard for A-law and m-law PCM of speech transported at 64Kb/s Compression codec supported for VoAAL2 solutions Compression code supported with effect from ISN05 Gratuitous ARP (broadcast indicating change in IP/MAC address mapping) Gigabit Ethernet Module (packet-side interface for IW-SPM) Gigabit Ethernet Grade of Service (resilience / availability of packet network) Graphical User Interface Gateway Gateway Controller (CS2000 peripheral housed in SAM21) Standard device control protocol for media gateway control (used for UAS) Set of ITU-defined IP protocols for conveying voice and other media types Hybrid Fibre Coax (used to support digital cable access networks) High-capacity XA-Core IOP supporting Ethernet (standard since ISN03) Higher-Level Management (OAM&P applications covering multiple NEs) Indirect Access Integrated Access Cable (network solution supported by CS2000) Integrated Access Device (combined line media gateway and WAN access device on customer premises) Initial Address Message (initiating ISUP or TUP call) Integrated Access Wireline (network solution supported by CS2000) Initial Boot Load (for GWC to notify GWC EM when installed) Integrated Business Network (support for proprietary value-added services) Proprietary variant of ANSI CCS7, providing networked support for IBN IPConnect Call Engine (alternative name for SoftSwitch or CS3000 TSS) Internet Draft (proposed IETF standards document) Information Element (ISDN parameter) Inter-Exchange Carrier Integrated Element Management System Internet Engineering Task Force (standards body for internet protocols) Interconnect ISUP Interactive Multimedia Server (pre-ISN07 name for MCS5200) Intelligent Networking Intelligent Networks Application Part (CCS7 protocol) Input-Output Module (datalink used to bring CS2000 into service) Input-Output Processor (XA-Core component) Internet Protocol Intelligent Peripheral (supports IN SRF functionality) IP Signalling Point (CCS7 node with IP signalling connection) Integrated Services Digital Network Integrated Service Module (used to house IOMs) International Succession Networks International Succession Networks Release 07 (described in this document) Internet Service Provider ISDN User Part (CCS7 protocol)

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ITU-T ITX IU IUA IVR IW-SPM Kb/s L2TP LAN LCI LCR LDAP LEA LEN LI LIS LMM LNP LNR LTM M2PA M2UA M3UA MAC Mb/s MCCS MCID MCMP MCS5200 MDCX MEGACO

International Telecommunication Union-Telecommunications Internet Telephony Extender (links between MG9000 shelves) Interface Unit (generic term for LIU and EIU) ISDN User Adaptation (IETF protocol to carry Q.921 user info, e.g. Q.931) Interactive Voice Response Interworking SPM Kilobits per second Layer 2 Tunneling Protocol (as used for RAS calls through packet network) Local Area Network Local Craft Interface Least Cost Routing Lightweight Directory Access Protocol Law Enforcement Agency Line Equipment Number (virtual physical address associated with line DN) Lawful Interception (regulatory service allowing an LEA to monitor calls) Link Interface Shelf (in FLPP) Line Maintenance Manager Local Number Portability Last Number Redial (line service) Line Test Manager

MTP2-User Peer-to-Peer Adaptation (for CCS7 messaging over IP network) MTP Layer 2 User Adaptation (superseded in ISN07 by M2PA) MTP Layer 3 User Adaptation (for CCS7 messaging via CS2000 CS LAN) Media Access Control (a MAC address is a Layer 2 network address) Megabits per second Multi-Country Call Server (one CS2000 with gateways in several countries) Malicious Call Identification Media Control Message Protocol (for specifying currency/language to UAS) Multimedia Communication Server 5200 Modify Connection (ASPEN message) Alternative name for H.248 media gateway control protocol (also the name of the IETF working group that developed H.248) MG Media Gateway (as defined in MEGACO architecture) MGC Media Gateway Controller (network role of CS2000) MGCP Media Gateway Control Protocol (used to control LAN line gateways) MIB Management Information Base (object-oriented SNMP information model) MIME Multi-purpose Internet Mail Extensions (for determining how to handle data) -law North American PCM standard used for speech path encoding/companding MMU Memory Management Unit MMUSIC IETF working group (originally responsible for SIP and SDP) MPC Multiple Point Code (ability for CS2000 to have up to 31 CCS7 point codes) MPCP Media Proxy Control Protocol (used to control RTP Media Portal) MPLS Multi-Protocol Label Switching (possible Layer 2 implementation for VoIP) MS Message Switch MTA Multimedia Terminal Adapter (line gateway supporting VoIP over cable) MTP Message Transfer Part (CCS7 part supporting OSI Layer 1-3 functions) MTU Maximum Transmission Unit (conveyed in an ATM service record) MWI Message Waiting Indicator NAOC NAPT Network Advice Of Charge (ISDN service) Network Address and Port TranslationPROPRIETARY Page


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NAT NCAS NCL NCOS NCS NDND NE NEL NEBS NFS NIC NIIF NLO NM NML NNSC NP NPM NRN NRR NSP NTFY NTMOS OAM&P OC OC-3 ODP OLEC OSS OSSDI PAM PBX PCL PCM PDP PE PEC PEEL PEP PID PLC PM PMDM POTS PP PP7480 PP8600 PP15000 PPVM PRI PS PSS1

Network Address Translation Non Call Associated Signalling (e.g. TCAP) Non-CM Load Network Class Of Service (mechanism for call screening) Network-based Call Signalling (between CS2000 GWC and MTA) Non-DMS Name Delivery Network Element Network Element Layer (in TMN hierarchy) Network Equipment Building System Network File Server (as used by CS2000-Compact) Network Identification Code (Nortel term for NRN, as used in NP) Network Interworking Industry Forum (predecessor to ACIF) New Licensed Operator (competing with an established PTT) Network Management Network Management Layer (in TMN hierarchy) Nortel Networks Service Class (for marking and prioritising traffic) Number Portability Network Patch Manager Network Routing Number (as used in NP) Network Re-Routing (of ISUP call if congestion is encountered) Network Services Platform (OAM&P desktop) Notify (ASPEN/NCS message indicating occurrence of monitored event) Network Traffic Management Operation System (near real-time trunk OMs) Operations, Administration, Maintenance and Provisioning Optical Carrier (SONET optical signal format) OC Level 3 (155 Mb/s, North American equivalent to STM-1) Open Dial Plan Originating Local Exchange Carrier Operations Support System (centralised OAM&P application) OSS Data Interface Pluggable Authentication Module Private Branch Exchange Product CM Load Pulse Code Modulation (as used to digitise speech) Policy Decision Point (for COPS-based CAC) Processor Element (XA-Core component) Product Engineering Code (Nortel hardware idenifier) Protel Environment Emulation Layer Policy Enforcement Point (for COPS-based CAC) Package Identifier (part of PID/TID used to denote a tone) Packet Loss Concealment (used to camoflage gaps in packetised speech) Peripheral Module Preside Multi-service Data Manager (for management of PVGs) Plain Ordinary Telephone System (basic telephony) Passport (family of ATM and IP switches and media gateways) Passport 7000 PVG Passport 8600 routing switch on which the CS2000 CS LAN is based Passport 15000 PVG Peripheral Processor Virtual Machine (CS2000 internal protocol) Primary Rate Interface (ISDN) Program Store (XA-Xore memory used to hold executable code) Private Signaling System No1 (QSIG)

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PSTN PTE PTE2000 PTM PVC PVC PVG QCA QoS

Public Switched Telephone Network Packet Telephony Equipment Frame used to house SAM21 shelves for GWCs and CS2000-Compact Packet Telephony Manager (old name for SSPFS / SESM) Permanent Virtual Circuit (statically allocated AAL2 or AAL5 channel) Protocol Version Control (used to distinguish PRI variants and issues) Packet Voice Gateway (PP7480 or PP15000 supporting VoIP or VoATM)) QoS Collector Application (for end-of-call QoS data provided by GWCs) Quality of Service

RAID Rapid Access Integrated Disk RAS Remote Access Service (support for dial-up data calls) RAS Registration, Admission and Status (H.323/H.225 capability) RES Resume (reactivate service to line) RFC Request For Comment (IETF document type for defining internet standards) RFC1350 Internet standards document for TFTP RFC1542 Internet standards document for BOOTP RFC1889 Internet standards document for RTP RFC2030 Internet standards document for SNTP RFC2045-9Internet standards documents for MIME RFC2131 Internet standards document for DHCP RFC2327 Internet standards document for SDP RFC2543 Internet standards document for SIP RFC2960 Internet standards document for SCTP RFC3015 Internet standards document for H.248 RFC3057 Internet standards document for IUA RFC3435 Internet standards document for MGCP RISC Reduced Instruction Set Computing RM Resource Module (for IW-SPM) RMGC Redirecting MGC (enables line media gateway to find IP address of GWC) RMI Remote Maintenance Interface RMP RTP Media Portal RQNT Request Notification (ASPEN/NCS message to initiate monitoring) RRC Re-Routing on Congestion (of ISUP call) RSA Registered Site Access (remote access to VPN) RSIP Realm-Specific Internet Protocol RTP Real Time Protocol (as used for media streams through IP network) RTCP Real Time Control Protocol (complements RTP by monitoring data delivery) SACB SAM SAM16 SAM21 SAPI SBC SCA SCC2 SCF SCF SCL SCP SCS SCSI Subscriber Activated Call Barring (line service) Service Application Module 16-slot CS2000 SAM used as UAS 21-slot CS2000 SAM used to house GWCs Service Access Point Identifier (for ISDN Layer 2/3 communication) Single-Board Computer Selective Call Acceptance (screening service for lines) Switching Control Centre 2 (format used to standardise multi-vendor logs) Service Control Function (for IN) Selective Call Forward (screening service for lines) Speed Calling, Individual Long List (line service) Service Control Point (for IN) Speed Calling, Individual Short List (line service) Small Computer System InterfacePROPRIETARY Page


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SCP CCS7 Service Control Point SCRJ Selective Call Rejection (screening service for lines) SCTP Stream Control Transmission Protocol (IETF reliable transport protocol) SCU Service Control Unit (term sometimes used for SAM21 housing GWCs) SDH Synchronous Digital Hierarchy SDM SuperNode Data Manager (hardware supporting PMSS XA-Core EM) SDN Secondary Directory Number (Teen Service) SDP Session Description Protocol (used to complement ASPEN and SIP-T) SEAL Simple and Efficient Adaptation Layer (AAL5) SESM Succession Element and Subnetwork Manager SFT Secure File Transfer SG Signalling Gateway (as defined in MEGACO architecture) SGC Succession Gateway Controller (term sometimes used for GWC) SIBB Service-Independent Building Block (for creating IN services) SIGTRAN IETF working group on IP transport protocols (SCTP, IUA, M2PA, M3UA) SIP Session Initiation Protocol (IETF protocol) SIP-T Session Initiation Protocol for Telephony (supports CCS7 encapsulation) SL Secondary Language SLE Screening List Editing SLG Log Generation SM Shared Memory (XA-Core component) SMDI Simplified Message Desk Interface (data link for voice mail) SML Service Management Layer (in TMN hierarchy) SMS Succession Management System (old name for PMSS) SN Succession Networks SNH Succession Networks based on H.248 (alternative name for ISN software) SNH01 First generally available SNH software release (predecessor to ISN03) SNM Succession Network Manager (software load supporting Core Manager) SNMP Simple Network Management Protocol (for EM/NE communication) SPFS Succession Platform Foundation Software SPM Spectrum Peripheral Module SRF Specialised Resource Function (for IN) SS Session Server SS7 Signalling System No. 7 (also called CCS7) SSF Service Switching Function (for IN) SSH Secure Shell SSP CCS7 Service Switching Point SSPFS Succession Server Platform Foundation Software SS-SS BCPSoftSwitch-SoftSwitch Best Common Practice (old name for SIP-T) SSV Sucession Subnet View SSV Semicolon-Separated Values (format for data file) STD Nortel standard log format STM Synchronous Transfer Mode (SDH signal format) STM-1 STM Level 1 (155 Mb/s, equivalent to OC-3) STORM Storage Manager (file storage for CS2000-Compact) STP CCS7 Signalling Transfer Point SU Service Unit (card used to support GWC functionality) SUS Suspend (deny service to line) SUSP Subscriber Usage-Sensitive Pricing (billing for feature usage) SVC Switched Virtual Circuit (dynamically allocated AAL2 or AAL5 channel) SWACT Switch of Activity (inactive standby unit taking over from active unit) TDM TEI Time Division Multiplexing (traditional telephony switching) Terminal Endpoint Identifier (for ISDN)

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TFTP TID TID TLEC TMM TMN TNS TR740 TR746 TSS TUP UA UAS UDP UP URI USP VBD VBR VLAN VM VME VoATM VoIP VRDN VRRP VSP WAN WML WUCR X.25 XA XAI XML

Trivial File Transfer Protocol Terminal Identifier (as used by XA-Core call processing to identify a trunk) Tone Identifier (part of PID/TID used to denote a tone) Terminating Local Exchange Carrier Trunk Maintenance Manager Telecommunications Management Network Transit Network Selection (CSP for intra-network use) Bellcore standard for DCOS performance data Bellcore standard for NTMOS performance data Telephony Soft Switch (e.g. CS2000) Telephony User Part (CCS7 protocol) User Adaptation Universal Audio Server (proprietary media server used by CS2000) User Datagram Protocol (unreliable / best-try protocol running over IP) Universal Port (gateway supporting dial-up RAS as well as VoIP) Uniform Resource Identifier (as used in SIP-T) Universal Signalling Point Voice Band Data Variable Bit Rate Virtual LAN (as supported by PP8600 routers) Voice Mail (line service) Versa Module Europe (industry hardware standards) Voice over ATM Voice over IP Virtual Routing Distribution Node (GWC supporting DPTs) Virtual Router Redundancy Protocol (as used between CS LAN PP8600s) Voice Service Processor (PVG component for circuit/packet conversion) Wide Area Network Warm Line (line service) Wake-Up Call Request (line service) ITU-T packet-switching standard Extended Architecture (as in XA-Core) Extended Architecture Interconnect (XA-Core internal comms links) Extensible Markup Language (data self-description via DTD and tags)


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Part A Overview

CS2000 International Product Description Communication Server Capabilities

Part A Overview

Chapter A1 Market Overview

Chapter A1

Market Overview

CS2000 is a key part of the Nortel Networks product portfolio for the support of converged carrier networks. Converged networks are managed IP core networks that simultaneously support real-time IP telephony, multimedia and a range of non-real-time data services. The justification for deploying them is that they can deliver a combination of immediate and longer-term benefits for network operators. The rationale for the initial deployment of converged networks is based on their enabling network operators to achieve cost savings in the short term, i.e. within two to five years. There are two main ways in which this short-term benefit can be realised: ! Network bandwidth can be used more efficiently. Bandwidth for voice traffic is used only when voice packets actually need to be transmitted, rather than being statically reserved as with TDM voice circuits. Bandwidth efficiency is also promoted by the ability to combine different traffic flows with varied requirements. ! Operational costs can be reduced because only one network infrastructure needs to be supported, which also simplifies management and maintenance via centralised OSS/BSS applications. Over the longer term, the main benefit of converged networks is their ability to serve as a unified platform for new services, particularly multimedia services that are genuinely integrated. As with traditional telecommunications networks, network operators will receive revenue both from services that they develop and provide directly, and from providing appropriate facilities to specialised service providers. Operators who choose not to make the strategic shift to converged networks will be unable to benefit from these new revenue streams, and may find themselves left behind as purveyors of legacy services and undifferentiated bandwidth with only commodity value. CS2000 is uniquely placed to enable network operators to adopt the new packet-based network architecture without having to restrict themselves in terms of the capabilities and services they can offer to their customers. This is because the CS2000 software load includes call processing agents, translations, routing, billing and services software that have been proven on other Nortel platforms in a wide range of international markets. New alternative operators can use CS2000 as the basis for future-proof networks that can compete cost-effectively with those of established operators. For such established operators, on the other hand, CS2000 can enable the transition from TDM to packet architecture to be seamless, with existing services remaining fully operational and continuing to generate revenue throughout the upgrade process.Issue ISN07_v3 (approved) 17 August 2004 PROPRIETARY Page

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Chapter A2A2.1

Network Overview

MEGACO Network ArchitectureThe network architecture implemented by CS2000 is based on a conceptual model defined by the IETF MEGACO (Media Gateway Control) working group [1]. This model specifies the logical functions that must be provided in a packet backbone network used to support multimedia traffic. Some of these logical functions exist within the packet network; others exist at its periphery, supporting access to the packet network from TDM networks and from various types of access network. A gateway provides an interface between two domains, e.g. between a packet network and a TDM network. This involves two types of gateway functionality: ! A media gateway provides an interface for bearer connections, e.g. mapping a packet-based media stream on to a circuit-based media stream, seamlessly providing any required format conversion while maintaining content integrity. A signalling gateway provides an interface for signalling connections. It terminates legacy network signalling on one side and packet network signalling on the other, and supports all necessary interpretation and conversion between the two.

!

These are logical functions, not node types. A given node may provide media gateway functionality, signalling gateway functionality, or both. Similarly, gateway functionality may be provided by a combination of nodes rather than a single node. Gateways provide basic connectivity across the packet network. Additional capabilities are provided by servers of various kinds within the packet network. In-band services such as announcements and video are provided by media servers. Call processing capabilities and related features are provided by communication servers (also known as call servers). The control and co-ordination of packet network gateways to support applications such as VoIP (Voice over IP) is the responsibility of a Media Gateway Controller (MGC). As with gateways, an MGC is a logical function, not a node type. MGC functionality may be provided by a combination of nodes rather than a single node, and it is possible for a given node to provide server functionality as well as MGC functionality.

[1] This working group was also responsible for specifying the H.248 protocol defined in RFC3015.


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Part A Overview

Chapter A2 Network Overview

Figure 1 provides a generic view of the MEGACO network architecture, illustrating the key principle on which it is based, i.e. the separation of media streams and signalling. Media streams are handled in accordance with MGC instructions, but are not handled directly by MGCs, only by media gateways and media servers. See Figure 2 on page 6 for an illustration of how this generic network architecture is implemented for a VoIP solution based on CS2000.Media Gateway Controller (MGC) Media Gateway Controller (MGC)

Core network (packet backbone)MGC-to-MGC signalling

MGC-MG signalling: PSTN CCS7 signalling (e.g. ISUP) Device/media control Backhauled call control Media server Announcements, conferencing Media Gateway (MG) Media stream, e.g. packetised voice

MGC-MG signalling: Device/media control Backhauled call control PSTN CCS7 signalling (e.g. ISUP) Page

Media Gateway (MG)

3 2 1

Different types of access (list not exhaustive): (1) CCS7 (trunk media gateway terminates TDM bearer channels only) (2) PRI PBXs, e.g. PRI (combined media and signalling gateway terminates bearer channels and supports backhaul of call control signalling to MGC) (3) Analogue lines (line media gateway terminates bearer channel and in-band DTMF)

3 2 1

PBX

PBX

TDM network, e.g. PSTNFigure 1: Generic view of MEGACO network archiecture


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Part A Overview


A2.2

CS2000 Implementation of MEGACO ArchitectureCS2000 is a communication server providing call processing capabilities. In terms of the MEGACO network architecture, it provides MGC functionality. Together with various types of gateway and server, it can support VoIP (Voice over IP) or VoATM (Voice over ATM), depending on the type of backbone packet network to be used. Specific CS2000 capabilities include: ! Basic connectivity and network element control " Control over the media gateways that provide the bearer connection interface between the packet network environment and other TDM or access networks. In ISN07, CS2000 supports the following types of access via media gateways: # CCS7 trunk access to/from the PSTN or another TDM network # PRI and QSIG access for digital PBXs and other PRI-enabled devices # V5.2 access, currently for analogue subscriber lines only # Analogue line access via a variety of gateway types, including CPE gateways attached to customer LANs or cable networks " Control over media servers supporting capabilities such as announcements and conferencing over the packet network. " Originations and terminations for inter-CS signalling across the packet network to/from other CS2000s and compatible MGCs such as MCS5200. " Originations and terminations for TDM-side CCS7 signalling. ! Call processing " A wide range of internationally proven call processing agents and protocols. " Translations and routing for calls entering, leaving and crossing the packet network. " Support for requests to apply tones and announcements. " Support for billing, event reporting and performance monitoring. ! Service support " Support for specific sets of value-added features. " Support for general-purpose service delivery platforms. " Support for regulatory features, e.g. lawful intercept and number portability. A CS2000 can be regarded as a single node, but it is not monolithic. The capabilities listed above are provided by separate CS2000 components (see section A2.3), of which the most important are Gateway Controllers (GWCs). These are used for two main purposes: ! To serve as controllers for media gateways, controlling their operation via device/media control signalling based on packet network protocols. Note: Depending on the type of access to be supported, a gateway may provide signalling gateway functionality as well as media gateway functionality, in which case the GWC and gateway will exchange call control signalling as well as media control signalling. This is the case with PRI, QSIG, V5.2 and analogue line access. ! To support communication between peer communication servers for the handling of networked calls. This is accomplished via inter-CS signalling, also based on packet network protocols. In the CS2000 architecture, GWCs are configured as CS2000 peripherals, but from an IP network perspective a GWC is an independent host with its own IP address. A range of packet network protocols have been developed for different types of communication in which GWCs are involved. The protocols supported by CS2000 GWCs are discussed in section A2.3.2. (Packet network protocols for communication between media gateways are outside the scope of this document; the most important is RTP/RTCP for VoIP bearer traffic.)

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Part A Overview


Figure 2 provides a schematic view of CS2000 network architecture for VoIP (OAM&P units omitted for simplicity).CS2000 Core supports: Call processing Translations / routing Service logic Core and GWCs together support MGC functionality. GWCs individually configured to support: Device/media control for MGs Backhauled call control for MGs H.323 access CICM control DPTs between CS2000s Media server control Media proxy control RMGC functionality Media server switched into calls to support: Announcements Conferencing BCT for LI USP supports CCS7 signalling to/from TDM networks via dedicated signalling links (not via packet network)

Session Server supports SIP signalling to/from peer MGCs

Media proxy switched into calls to support NAT traversal for media streams between IP address domains

CICM provides services for remote CentrexIP clients

CS2000 CS LANCS2000 Core MS2000 GWCs CICM USP Session Server Session Server

CS2000 CS LANCS2000 Core

GWCs

MS2000

CICM

USP

Dual PP8600s

Media proxies

Dual PP8600s

Core networkPVG PVG PVG MG9000 Customer Edge (CE) router CCS7 trunks PRI or QSIG PBX V5.2 H.323 access to core network for: M1 IP PBX BCM CSE1000 Cisco routers DPNSS GW Customer Edge (CE) router

Access or enterprise network

Enterprise network

V5.2 AN Lines and ADSL

CentrexIP clients Low-capacity media gateways, e.g. IAD, MTA

PSTN or other TDM network

Figure 2:

CS2000 network architecturePROPRIETARY Page


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Part A Overview


A2.3A2.3.1

CS2000 Support for Network ArchitectureHardware Support

A2.3.1.1 CS2000 Components In CS2000 release ISN07, the allocation of Communication Server functionality to CS2000 components is as follows (see Chapter B1: CS2000 Hardware for details): ! ! Call processing, translation, routing and service logic are supported by the CS2000 processor complex (Core). The CS2000 CS LAN that links CS2000 components and enables them to communicate with the managed IP core network is supported by dual PP8600 routing switches. CCS7 signalling gateway functionality is supported in two ways:"

!

"

For communication between the CS2000 network and TDM networks such as the PSTN, CCS7 signalling is supported by the termination of TDM-side CCS7 signalling links on either the Universal Signalling Point (USP) or the FLPP (Fiberised Link Peripheral Processor). The corresponding trunks are terminated on trunk media gateways controlled by GWCs. For communication across the managed IP core network between peer MGCs, CCS7 is supported using DPTs (Dynamic Packet Trunks) terminated on DPT GWCs. CCS7 signalling is conveyed encapsulated in SIP (Session Initiation Protocol) messages. SIP signalling is terminated on the Session Server, which extracts the CCS7 signalling and passes it on to the DPT GWC. Note: Session Server support for SIP signalling and CCS7 encapsulation is designed to be compliant with RFC3261, which defines a SIP interface for open interoperability between call servers and other network elements. Prior to the ISN07 introduction of the Session Server implementation, CS2000 support for SIP was based on pre-RFC3261 drafts and implemented by configuring GWCs as VRDNs (Virtual Router Distibution Nodes) to provide initial points of contact for peer-to-peer SIP signalling. This VRDN implementation is still supported, but has now been superseded by the Session Server implementation.

!

GWCs can be configured to support and control VoIP access to the managed IP core network for a wide range of media gateways and other units, as follows:" " " " " "

Trunk media gateways supporting CCS7 trunks to/from the PSTN or other TDM networks. Trunk media gateways supporting PBX interfaces (PRI, QSIG, DPNSS). V5.2 gateways supporting V5.2 access, currently for analogue lines only. Large carrier-located line media gateways supporting analogue subscriber lines and ADSL (Asymmetrical Digital Subscriber Line) data access. H.323-controlled units such as IP-enabled PBXs and third-party routers. Low-capacity CPE line media gateways supporting access for analogue subscriber lines attached to customer LANs or cable access networks.

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"

Remote CentrexIP clients attached to enterprise networks. Note: CentrexIP clients are not controlled directly by GWCs, but by a CICM (CentrexIP Client Manager) on the CS LAN; the CICM is in turn controlled by a GWC. It is a twin-card unit that is housed alongside GWCs. Universal Port (UP) gateways supporting RAS dial-up access to internet and/or intranet data sessions as well as VoIP voice calls.

"

!

Dynamic Packet Trunks for inter-CS signalling based on CCS7 encapsulated in SIP (Session Initiation Protocol) are supported by DPT GWCs with no subtending units. DPTs are so called because trunk characteristics such as the ISUP protocol variant to be used are determined on the basis of the telephony profile of the selected route, which is downloaded to the DPT GWC during call establishment. To support inter-CS signalling, the operation of DPT GWCs is co-ordinated with that of one or other of the following unit types: " The preferred implementation with effect from ISN07 is based on DPT GWCs interacting with the Session Server. SIP signalling is terminated on the Session Server, which extracts the CCS7 signalling and passes it on to the DPT GWC."

Prior to ISN07 (and still supported for existing deployments), the standard implementation was based on a DPT GWC interacting with another GWC configured as a VRDN (Virtual Router Distibution Node) to provide an externally visible IP address as a point of initial contact for its host CS2000 In this implementation, DPT GWCs were responsible for terminating SIP signalling and extracting CCS7. See Figure 13 on page 62 for an illustration of how DPT GWCs interact with these other units to support inter-CS communication via SIP. Note: Session Server support for SIP signalling and CCS7 encapsulation is designed to be compliant with RFC3261, which defines a SIP interface for open interoperability between call servers and other network elements. The VRDN implementation was based on pre-RFC3261 drafts and has now been superseded by the Session Server implementation. ! GWCs can also be configured to support a range of gateways and other units that provide specialised service support functionality, as follows: " GWC for MS2000 Series media servers, which support: # Announcements # Conferencing # Bearer Channel Tandeming (BCT) functionality for call monitoring via the LI (Lawful Interception) regulatory service Note: MS2000 Series media servers are compact, enhanced versions of the UAS (Universal Audio Server), which provided media server functionality prior to ISN07. Deployed UASs are still supported, but MS2000 Series media servers are to be used for new deployments. " GWC for RTP Media Portal providing media proxy functionality The RTP media portal is a GWC-controlled media proxy. Its primary purpose is to support public address discovery for media streams that have been routed via a NAT. The media portal examines incoming packets on each of its ports to determine their origin, and can thus work out the destination to which return packets in the other direction should be sent. In a carrier networkPROPRIETARY Page


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supporting a CS2000 solution, each media proxy has two connections, one with the private VoIP network and one with the carriers public network. This enables it to support two specific capabilities: # It supports communication with and between private address domains, e.g. for enterprise networks hosting line media gateways and CentrexIP clients, by enabling media streams that traverse NATs to be routed across the carriers public network. # It can act as a firewall to control the traversal of media streams into the private VoIP address domain used for the CS2000 CS LAN and large telco-located gateways. ! A GWC can be configured to support Redirecting Media gateway Controller (RMGC) functionality, which enables line gateways to discover the address of their controlling GWC.

The hardware characteristics of all types of GWC are essentially the same. CS2000 datafill is used to specify the intended function of each GWC and ensure that its software load is configured appropriately. From an IP network perspective, a GWC is an independent host with a Layer 3 IP address that is externally visible, i.e. reachable from the carriers public network, plus other IP addresses for CS2000 use. Other CS2000 components that have externally visible IP addresses are: ! ! ! ! ! USP Session Server CICM Media servers (not strictly speaking CS2000 components, but typically on the CS LAN) RTP Media Portal (not strictly speaking a CS2000 component, but can be on the CS LAN)

The IP addresses of the CS2000 Core are not externally visible. The FLPP (if used) supports only TDM-side functionality, and has no IP address.

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A2.3.1.2 Gateways and Other GWC-Controlled Units CS2000 release ISN07 supports the use of the gateway types listed below: ! Media gateways Note: Media gateways are independent units with their own release schedules. The range of supported gateways may therefore change within the life-cycle of a given CS2000 release."

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Passport PVGs (Packet Voice Gateways) configured to support trunk access PVGs can support either VoIP or VoATM for CCS7, ISDN PRI and QSIG trunks. Two hardware platforms can be used to provide PVG capabilities: # PP7480 # PP15000 PVGs configured to support V5.2 access for analogue lines PVGs can support VoIP for V5.2 interfaces supporting analogue lines. The architecture and physical characteristics of a PVG configured to support V5.2 access are the same as those of a PVG configured to support trunk access. High-capacity line media gateways, typically located on operating company premises. In ISN07, CS2000 supports the MG9000, a high-capacity media gateway for analogue lines and ADSL (Asymmetrical Digital Subscriber Line) access. The largest MG9000 configuration supported can terminate up to 5920 POTS lines. CPE gateways and 3rd-party units controlled by CS2000 H.323 proxy (GWC equivalent) via H.323 / H.225 / H.245: # IP-enabled Meridian 1 PBXs # IP-enabled Business Call Manager (BCM) PBXs # CSE1000 Call Server for Enterprise # Westell DPNSS gateways (DPNSS signalling encapsulated in H.323) # Cisco 2600/3600 access routers CPE line media gateways attached to customer LANs, which are in turn connected to the IP backbone network. Signalling between the GWC and the media gateway is supported end-to-end using an IP Layer 3 protocol. Two gateways of this type are used to support VoIP in ISN07: # Ambit line media gateways and IADs supporting 1, 16 or 32 ports # Askey line media gateways supporting 4, 12 or 30 ports # Mediatrix 1124 line media gateways supporting 24 ports CPE line media gateways attached to cable access networks to support VoIP for analogue subscriber lines. Two types of gateway can be used to support these capabilities: # Motorola MTA (Multimedia Terminal Adapter) # Arris MTA An MTA line gateway is not directly connected to the IP backbone network. Instead, it is connected to a HFC (Hybrid Fibre Coax) cable access network, which is in turn connected to the IP backbone network via a CMTS (Cable Modem Termination System) and a PP8600 router. Signalling between the GWC and the MTA is supported end-to-end using an IP Layer 3 protocol, conveyed over the IP backbone for part of the way and over the HFC network for the rest.PROPRIETARY Page

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Universal Port (UP) gateways that support RAS dial-up access to internet and/or intranet data sessions via CCS7 trunks, as well as VoIP voice calls. The gateway type used for this purpose in ISN07 is the CVX1800. Note: CS2000 support for RAS has been tested and verified for deployment only in a specific customer network, and is not generally available in ISN07.

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Remote CentrexIP clients controlled by the CentrexIP Client Manager (CICM) CS2000 provides VoIP support for two types of CentrexIP client: " Etherset clients IP-enabled Ethernet telephone sets with a large display and programmable softkeys. " Soft clients PCs running a telephony client application, with speech transmission and reception supported via a headset attached to the PC and call control capabilities provided by a screen-based GUI. CentrexIP clients are controlled by the CentrexIP Client Manager (CICM). CS2000 perceives the CICM as a large gateway and CentrexIP clients as lines served by CICM gateways, but the CICM is not a media gateway in MEGACO terms because it handles only signalling traffic, not media streams. It can be regarded as a terminal server, and its role is similar to that of a GWC controlling multiple small CPE line gateways. CICMs are connected to the CS2000 CS LAN, and communicate with their remote CentrexIP clients over the managed IP network. Each CICM subtends and is controlled by a CS2000 GWC. MS2000 Series media server or Universal Audio Server (UAS) MS2000 Series media servers are enhanced, compact versions of the UAS available with effect from ISN07, though deployed UASs continue to be supported. Both types of unit provide essentially the same media server capabilities, as follows: " Packetised announcements provided to call parties in response to CS2000 requests. Note: In general, tones are provided by gateways directly to their TDM-side trunks and lines, not by a media server. " Conference circuits for multi-party calls across the packet network. " Bearer Channel Tandeming (BCT) functionality for the LI (Lawful Interception) regulatory service, which allows packet network bearer connections to be monitored by an LEA (Law Enforcement Agency). MS2010 media servers for VoIP are housed in a 1U chassis designed to be mounted horizontally in a standard 19" frame; MS2020 media servers for VoATM are housed in a 2U chassis. UASs are housed in 16-slot SAM16 shelves. Media servers are co-located with the CS2000 and connected to the CS LAN. In terms of CS2000 network architecture, however, a media server subtends a GWC, although it cannot be categorised as a media gateway because it has no TDM-side connections.

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RTP Media Portal The RTP media portal is a GWC-controlled media proxy. Its primary purpose is to support public address discovery for media streams that have been routed via a NAT. The media portal examines incoming packets on each of its ports to determine their origin, and can thus work out the destination to which return packets in the other direction should be sent. In a carrier network supporting a CS2000 solution, each media proxy has two connections, one with the private VoIP network and one with the carriers public network. This enables it to support two specific capabilities: " It supports communication with and between private address domains, e.g. for enterprise networks hosting line media gateways and CentrexIP clients, by enabling media streams that traverse NATs to be routed across the carriers public network. " It can act as a firewall to control the traversal of media streams into the private VoIP address domain used for the CS2000 CS LAN and large telco-located gateways.

From a packet network perspective, each media gateway is an independent node with its own Layer 2 and Layer 3 addresses. A media gateway may have multiple addresses for different purposes, as follows: ! ! ! ! Either IP or ATM addressing is used for originating and terminating media streams. IP addressing is used for VoIP; ATM addressing is used for VoATM, and for VoIP over AAL5 over ATM. IP addressing is used for device/media control signalling between a media gateway and its GWC. IP addressing is used for backhauled call control signalling between a media gateway and its GWC (PRI, QSIG, V5.2 and analogue line access only; not applicable for CCS7). IP addressing is used for OAM&P signalling between a media gateway and its EM (Element Manager).

For further information about the capabilities of the media gateways supported by CS2000, see Chapter B2: CS2000 Support for Media Gateways. See Chapter B3: CS2000 Support for Media Servers for information about the UAS.


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A2.3.2

Software Support

A2.3.2.1 Packet Telephony Protocols Because a CS2000 network is a distributed system rather than a monolithic unit, it is necessary to consider CS2000 support for the IP protocols that are internal to the packet network as well as the telephony interfaces that the CS2000 supports externally. Several different types of IP signalling are involved in setting up calls across the packet network, as summarised in the remainder of this section. See Part DPacket Telephony Protocols for descriptions of each protocol, and particularly Figure 64 on page 236 for an illustration of the protocol stacks with all the acronyms expanded. Note: All packet network signalling is conveyed using IP at Layer 3, regardless of the backbone network type. Intra-CS signalling uses IP over 100BaseT Ethernet. Signalling between CS2000 and the packet backbone uses either IP over Gigabit Ethernet (for an IP backbone network) or IP / AAL5 / ATM (for an ATM backbone network). Protocol stacks used in setting up calls across the packet network: ! ! ! ! Access signalling between Gateway Controllers (GWCs) and media gateways. Network signalling between peer Communication Servers. SDP (Session Description Protocol) session description signalling specifying bearer capabilities and address information. CCS7 signalling within the CS2000 itself.

These different types of packet network signalling are described in separate subsections on the following pages. Another packet network protocol supported supported by CS2000 is SNMP (Simple Network Management Protocol). This is a general-purpose OAM&P interface for the management and maintenance of network elements in a packet network. It is not used in setting up calls. In a CS2000 network, it is used by the GWC EM (Element Manager) to communicate with the GWCs it controls. Access Signalling between Gateway Controllers (GWCs) and Media Gateways Two types of access signalling are supported: ! Media or device control signalling that allows the GWC to control the characteristics of the packet network bearer connections used for a call. Protocols supported in ISN07: " H.248 / UDP / IP # Communication with PVGs configured as trunk or V5.2 gateways. # Communication with large telco-located MG9000 line gateways. # Communication with the CentrexIP Client Manager (CICM) that controls remote CentrexIP clients. # Communication with media servers to support announcements (tones are provided by gateways), conferencing, LI and trunk testing. H.248 is a joint ITU-T / IETF protocol defined in ITU-T Recommendation H.248 and IETF RFC3015. It fully supports the same basic device/media control capabilities as the proprietary ASPEN protocol that it has now superseded (see below). More importantly, it is based on a more flexible functional model that provides better support for multimedia and conference capabilities.Page PROPRIETARY Issue ISN07_v3 (approved) 17 August 2004

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ASPEN / UDP / IP Communication with PVGs configured as trunk gateways, in support of VoIP or VoATM. ASPEN is a proprietary protocol based on standard MGCP. It is a superset of MGCP, supporting the same standard connection control commands plus a number of additional proprietary commands defined to provide extra maintenance functionality. It is still supported, but has now been superseded by the standard H.248 protocol (see above). H.323 / (TCP or UDP) / IP H.323 is an ITU-defined umbrella specification for use in the definition and implementation of multimedia services supporting the integration of voice, video and data applications. It should be regarded as a framework or architecture rather then a protocol in its own right, because it actually comprises a number of different protocols. The underlying control protocol in the H.323 architecture is H.225, which provides esentially the same range of call control messages as those defined in Q.931. More importantly, H.225 allows other types of H.323 signalling to be conveyed in order to support enhanced capabilities, as follows: # H.225 defines RAS (Registration, Admission and Status) messages and procedures for controlling access to the network. # H.450 protocols provide service-related data definitions in ASN.1 format. # H.245 defines messages and procedures to be used in setting up and taking down logical channels within the context of a H.225 call. UniStim / RUDP / UDP / IP UniStim is the protocol used by the CentrexIP Client Manager to communicate with CentrexIP remote clients. It is a Nortel Networks protocol, but is available under licence to other equipment vendors who wish to design and manufacture CentrexIP-compatible terminals. UniStim is a stimulus protocol whose command set enables a Network Intelligence (NI), i.e. CICM, to control every aspect of the operation of a client Internet Terminal (IT). To provide reliable transport over UDP, UniStim uses a simple Go-Back-N scheme to provides a suitable Reliable UDP (RUDP) layer for UniStim. NCS / UDP / IP Communication with cable network line gateways, in support of VoIP. NCS (Network-based Call Signalling), which is also based on MGCP, is designed to support embedded VoIP client devices in a PacketCable environment; it supports call control signalling as well as media control. It is defined in PacketCable(TM) specification PKT-SP-EC-MGCP-I10-040402 (or later issue found at http://www.packetcable.com/specs). MGCP / UDP / IP Communication with customer LAN line gateways, in support of VoIP. MGCP (Media Gateway Control Protocol) is a protocol defined in IETF RFC3435.


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MPCP / UDP / IP Communication with RTP Media Portal to support media proxy functionality, specifically to support public address discovery for media streams that have been routed via a NAT. It thus makes NAT traversal possible for media streams, and supports communication with and between private networks. MPCP (Media Proxy Control Protocol) is a version of standard MGCP enhanced with proprietary extensions designed to support multimedia sessions and NAPT. DSM-CC / UDP / IP Communication with CVX1800 UP gateways, in support of RAS and VoIP. The Digital Storage Media Command and Control (DSM-CC) protocol is a toolkit for developing control channels associated with MPEG-1 and MPEG-2 streams. It is defined in a series of standards, of which the most important is MPEG-2 ISO/IEC 13818-6, i.e. Part 6 of the MPEG-2 standard: Extensions for DSM-CC.

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Backhauled call control signalling (setup and clearing messages) for message-based non-CCS7 interfaces such as ISDN PRI, QSIG and V5.2, for which access network signalling is terminated at the media gateway. Protocol stacks supported in ISN07:"

Q.931 / IUA / SCTP / IP " QSIG / IUA / SCTP / IP " V5.2 / V5UA / SCTP / IP " DPNSS / H.323 / TCP / IP, which is interworked at the H.323 GWC to DPNSS over QSIG IUA (ISDN User Adaptation) over SCTP is defined in RFC3057. SCTP is defined in RFC2960. V5UA (V5 User Adaptation) is defined in draft-ietf-sigtran-v5ua. ! Call control signalling for analogue subscriber lines. Protocol stacks supported in ISN07: " H.248 / UDP / IP (for lines served by high-capacity MG9000 gateways) " MGCP / UDP / IP (for lines served by gateways on customer LANs) " NCS / UDP / IP (for lines served by MTA gateways on cable networks) In these cases, the protocol used for call control is the same protocol used for media control, i.e. one protocol supports both types of signalling. Call control signalling allows the GWC to be informed of events such as hook state changes, to initiate digit collection, and to request the application of ringing and in-band tones.

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Network Signalling between Peer Communication Servers Three types of peer-to-peer signalling are supported: ! Circuit-oriented ISUP or TUP signalling CCS7 is supported using DPTs (Dynamic Packet Trunks) terminated on DPT GWCs. ISUP or TUP messages are conveyed across the managed IP core network encapsulated within SIP-T messages by means of the MIME mechanism. The protocol stack used is therefore: " SIP-T (ISUP or TUP) / (TCP or UDP) / IP CS2000 supports two different implementations of SIP / SIP-T. With effect from ISN07, the recommended implementation is based on the use of the Session Server to terminate SIP-T signalling. Session Server support for SIP signalling and CCS7 encapsulation is designed to be compliant with RFC3261, which defines a SIP interface for open interoperability between call servers and other network elements. In this implementation, SIP signalling is terminated on the Session Server, which extracts the CCS7 signalling and passes it on to the DPT GWC. Prior to the ISN07 introduction of the Session Server implementation, CS2000 support for SIP was based on RFC2543 and other pre-RFC3261 drafts and implemented by configuring GWCs as VRDNs (Virtual Router Distibution Nodes) to provide initial points of contact for peer-to-peer SIP signalling. In this implementation, the DPT GWC is responsible for terminating SIP-T signalling as well as CCS7 signalling. This VRDN implementation is still supported, but has now been superseded by the Session Server implementation. SIP signalling with no encapsulated CCS7 signalling SIP without CCS7 encapsulation is used for communication between CS2000 and the Multimedia Communication Server 5200 (previously known as IMS). This is a Nortel product that supports access to multimedia services and advanced telephony features for SIP clients. Because no encapsulated CCS7 messages are included in the SIP-T message, the CCS7 meaning of each SIP-T message must be inferred from the message header and parameters. In ISN07, the only CCS7 protocol that can be emulated is this way is IBN7 (ANSI ISUP+). Protocol stack: " SIP-T (no CCS7) / (TCP or UDP) / IP TCAP-based NCAS (Non Call Associated Signalling) The CS000 USP used to terminate CCS7 signalling links with TDM networks can also support NCAS with remote CS2000s (strictly speaking, with USPs belonging to remote CS2000s) via the managed IP core network. Protocol stack:"

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TCAP / SCCP / MTP3 / M2PA / SCTP / IP M2PA (MTP2-User Peer-to-Peer Adaptation) is an IETF protocol for communication over a packet network between systems with different CCS7 point codes. It is defined in draft-ietf-sigtran-m2pa. Note: The USP could also support ISUP or TUP signalling between CS2000s over MTP3 / M2PA / SCTP / IP, but this capability is not used by the CS2000 international product. SIP-T encapsulation of ISUP or TUP is used instead.


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SDP (Session Description Protocol) session description signalling SDP signalling is used to complement both GWC-gateway signalling and inter-CS signalling by specifying bearer capabilities and address information. SDP is defined in IETF standards document RFC2327. For VoIP, SDP conveys IP address information as specified in RFC2327. For VoATM, SDP conveys ATM address information by means of SDP extensions defined in a complementary ID (Internet Draft). See Chapter D1.3: Session Descriptions (SDP) for more details. SDP information is conveyed in one of two ways: ! ! To complement GWC-gateway signalling using H.248, ASPEN, NCS or MGCP, SDP information is provided inside the device control messaging. To complement SIP-T inter-CS signalling, SDP information is encapsulated via the MIME mechanism in the same way as ISUP messages (but separately).

Codec negotiation takes place between the media gateways involved in a call to determine the correct codec to use. The aim is that the codec used should be the codec that is highest in preference order and supported by both gateways. An SDP session description is used to convey the capabilities of each media gateway to its GWC and to the far-end gateway. An appropriate codec is then selected from the intersection of both gateways sets of capabilities. Intra-CS2000 CCS7 Signalling Within a distributed system whose components can be accessed via a single CCS7 point code, M3UA (MTP Layer 3 User Adaptation) can be used to convey user part messages between those components. Each incoming message is distributed to the appropriate component and presented to the appropriate user part (ISUP, TUP, TCAP) exactly as if MTP Layer 3 was doing the distribution rather than M3UA. In a CS2000 that uses the USP to terminate CCS7 signalling, the USP and the Core share the same point code, and the USP uses M3UA to distribute incoming CCS7 messages to the Core and directly to GWCs. Use of M3UA over the CS2000 CS LAN between USP and the Core makes it unnecessary for the Core to provide MTP3 functionality. The protocol stack used is CCS7 (Layers 4-7) / M3UA / SCTP / IP.

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