UMTS IP Bearer Basics

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IP Basis

Applicable to Staff with Skill Certificate Level II or LowerReleased by GU Product Support Dept.

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Version Introduction

References:

1.

2.

Version Date Author Checked by Amendment Record

R1.0 2010-04-21 Lei Haiting ***

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Course Objectives:

To understand the basic concepts of IP transmission

To understand IP application in UMTS

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Contents

IP Basis

IP Transport in UMTS

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IP Basic Concepts

IP Address

TCP/IP-IP Layer

TCP/IP Transport Layer

TCP/IP Application Layer

IP Basis Subdirectories

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The ISO OSI- RM

Application

Network

Physical

Data Link

Session

Transport

Presentation

International Standardization OrganizationOpen Systems Interconnection-Reference Model

internationally accepted framework for data networks essential to understand data communication principles allows different systems to interconnect “Protocols” are used at different levels for

communication

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The ISO OSI- RM

Physical Layer

Data Link Layer

Network Layer

Transport Layer

Session Layer

Presentation Layer

Application Layer

•10Base- T, EIA 232- D

•Two sublayers, Mac and LLC•Bit level error checking

• Routing functionality• Addressing and address resolution• Routing table maintenance

•Data level error checking•Reliable end to end data transmission

• Establishment, removal, and synchronization of sessions between two processes

• Data Conversion• Protocol Conversion

• Provides the user with access to the network environment

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OSI Reference Model- Layers and Protocols

Entity (N+1) Entity (N+1)Layer (N+1)

(N+1)SAP(N+1)SAP

Protocol (N+1)

(N)SAP (N)SAP

Service (N+1)

Service (N)

SDU SDU

PDUPDU

Primitives of Layer (N+1) Primitives of Layer (N+1)

Entity (N) Entity (N)Layer (N)Protocol (N)

SDU SDU

NO Protocol

PDUPDU

(N-1)SAP (N-1)SAPService (N-1)

1 : Physical

2 : Data Link

3 : Network

4 : Transport

5 : Session

6 : Presentation

7 : Application

Open SystemsInterconnectionReference Model

Physical bearerof interconnection

SAP = Service Access PointSDU = Service Data UnitPDU = Protocol Data Unit

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OSI Reference Model- Communication between Layers

Layer N SDU

Layer N PDUHeader

Layer N PDUTrailerLayer N PDU Payload

Layer N + 1Data

SAP

SAP

Layer (N+1)

Layer (N)

Layer (N-1)

Layer N-1 SDU

Layer N-1 PDUHeader

Layer N-1 PDUTrailer

Layer N-1 PDU Payload

N-SDU

N-PDU

N-PCI

PCI = Protocol Control Information

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OSI vs TCP/IPTCP/IP Protocol StackOSI RM

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OSI vs TCP/IP-protocols

EthernetEthernet Token BusToken Bus Token RingToken Ring FDDIFDDI

Internet ProtocolInternet Protocol

ARPARP

TELNET FTP SMTP DNS SNMP DHCPTELNET FTP SMTP DNS SNMP DHCP

DatalinkDatalinkPhysicalPhysical

NetworkNetwork

TransportTransport

ApplicationApplicationPresentationPresentationSessionSession

ICMPICMPIGMPIGMP

RTPRTPRTCPRTCP

TransmissionTransmissionControl ProtocolControl Protocol

User DatagramUser DatagramProtocolProtocol OSPFOSPF

RIPRIP

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Standard Applications

TELNET: Provides remote terminal emulation FTP: Provides a file transfer protocol TFTP: Provides for a simple file transfer

protocol SMTP: Provides a mail service DNS: Provides for a name service BOOTP/DHCP: Provides for management of IP

parameters

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Encapsulation-Principles

WorkstationWorkstation

DataData

TCP SegmentTCP Segment

DatagramDatagram

PacketPacket

ApplicationApplication

TCPTCP

IPIP

Data LinkData Link

FrameFrame

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Data Encapsulation Process-1

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Data Encapsulation Process-2

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IGP & EGP

Routing protocol Vs Routable protocol.

• A routing protocol is one that is used to propagate route path information on a network.

• A routable protocol is one that has the ability to be routed as opposed to a non routable protocol such as NetBIOS.

IGPs are used as routing protocols within an AS.

EGPs are used as routing protocols between ASs.

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Fragmentation-MTU

Datagram!!1600 bytes

Not more than MTU bytes !!

Ok, I’ll send itin 2 steps!!

Router

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IP Basic Concepts

IP Address

TCP/IP-IP Layer




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IP vs MAC

Physical AddressPhysical Address: NIC numbers

44-45-53-54-00-00

IP addresses of PC connected to the Network.

129.21.10.49

IP addresses are not the same as the

underlying data-link (MAC) addresses.

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IP Address Basics

32 bit addresses divided into four 8 bit fields.

Decimal Dotted Notation.

136.147.117.33

The first part of the address identifies the network

while the second part specifies the host number.

“Three” classes of addresses.

Host AddressHost AddressNetwork AddressNetwork AddressAddress Address IdentifierIdentifier

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Addresses Classes

• Uses the first two bytes of the address to identify the network number.• Allows for 16,384 network numbers.• Allows for 65,354 hosts per network number.• 128 - 191 in the first field with 0 - 255 in the second field allowed.

• Uses the first byte of the address for a network number.• Allows for up to 126 network addresses.

– 0 and 127 are reserved• Allows for up to 16,277,214 hosts per network ID.• The host field cannot have all 0s or all 1s.

Class AClass A

Class BClass B

Class CClass C

Class DClass D

Class EClass E

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

0 NET ID Host ID

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

1 0 NET ID Host ID

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

1 1 0 NET ID Host ID

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

1 1 1 0 Multicast address in the range of 224.0.0.0 - 239.255.255.255

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

1 1 1 1 0 Class E - Reserved for future use

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Address Classes

Class Network ID First Host Last HostAFirst Network 1.0.0.0 1.0.0.1 1.255.255.254Last Network 126.0.0.0 126.0.0.1 126.255.255.254BFirst Network 128.1.0.0 128.1.0.1 128.1.255.254Last Network 191.254.0.0 191.254.0.1 191.254.255.254CFirst Network 192.0.1.0 192.0.1.1 192.0.1.254Last Network 223.255.254.0 223.255.254.1 223.255.254.254

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Subnet Mask

10001000 10010011 11001000 00000101

The networkThe host

11111111 11111111 11110000 00000000

255.255.240.0

/20

136.147.200.5/20

136.147.200.5

The sub network

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IP Address Restrictions

Address cannot have the first four bits set to 1.

Class A address of 127.x.x.x is reserved for loopback.

The host portion of the address cannot be set to all 0 s or all 1 s.

All 0 s and all 1 s are allowed in the subnet.

Any address with all 0 s in the network portion corresponds to the

local network.

Old form of broadcasting (all 0 s in the address) is no longer used.

IP addresses may be configured without registration.

Addresses cannot be out of the 255 range for each byte.

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IP Basic Concepts

IP Address

TCP/IP-IP Layer




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TCP/IP comprises two types of services: connectionless service, and service oriented toward connection.

Basic distribution services are connectionless, and reliable service oriented toward connection is based on the connectionless service.

Connectionless internet packet exchange can be extended: This service allows the source to transfer data packets over Internet. With the destination address, each data packet looks for the correct path independently.

The source host generates a data packet, saves the destination address in its header, and sends the packet to an adjacent router. When the router gets the packet, it will choose the next-hop router that can lead to the destination and transmit the packet to it. In this way, the data packet goes through a number of routers and arrives at it destination.

Internet Protocol(IP)

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Format of IP Datagram:

Datagram is a data packet that crosses over TCP/IP network.

Each datagram comprises two parts: header and data. The header contains the source and the destination address while the data contains user data.

The datagram length is changeable, but it should not exceed 64 KB.

IP Datagram and Route

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Transmission of IP Datagram:


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IP Address and Route Table Entrance:


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IP address is an abstract address provided by the software while the physical network hardware doesn’t know how to find another computer via IP address.

Before the datagram are transferred, the next-hop IP address must be translated into equivalent hardware address (hardware address). The mapping between IP address and hardware address is called address resolution;

Before a host or a router transfers datagram to another host in the same physical network, address resolution must be performed;

It is unnecessary for a computer to perform address resolution on the computer connected in a remote network (i.e. different physical network).

Address Resolution Protocol (ARP)

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Address resolution messages are distributed as follows: Computer A starts to broadcast an application message that contains the IP address of Computer B;

All the computers get the application message;

Only Computer B replies Computer A with a response message.

Address Resolution Protocol (ARP)

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Address Resolution Protocol Operation-1

ARP Request

Here is my Here is my MAC addressMAC address

129.1.1.1129.1.1.1 BB CC 129.1.1.4129.1.1.4NotNotmeme

Not Not meme

That’sThat’smeme

RequestRequestIgnoredIgnored


ARP ResponseARP ResponseAcceptedAccepted

Give me the MAC address of station 129.1.1.4Give me the MAC address of station 129.1.1.4

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Address Resolution Protocol Operation-2

ARP Request

Here is my Here is my MAC addressMAC address

129.1.1.1129.1.1.1 BB CC 129.1.1.4129.1.1.4NotNotmeme

Not Not meme

That’sThat’smeme



ARP ResponseARP ResponseAcceptedAccepted

Give me the MAC address of station 129.1.1.4Give me the MAC address of station 129.1.1.4

I’ll remember it

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IP Basic Concepts

IP Address

TCP/IP-IP Layer




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The Transport Layer

Application

Network

Physical

Data Link

Session

Transport

Presentation Transport LayerTransport Layer

IPIP

UDP: User Datagram ProtocolUDP: User Datagram Protocol

TCP: Transmission Control ProtocolTCP: Transmission Control Protocol

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TCP is a service provided to application.

As a protocol at the transfer layer, TCP provides TCP/IP stack with reliable communication. It functions includes:

Communication oriented toward connection; Point-to-point communication; Complete reliability; Full-duplex communication; Streaming interfaces; Reliable connection establishment; Perfect disconnection.

TCP

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TCP Header Fields

ReservedData offset

Window

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

Source port Destination port

Sequence number

Acknowledgment number

URG

ACK

PSH

RST

SYN

FIN

Checksum Urgent pointer

<== Options ==> Padding

TCP data

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The Three-Way Handshake

SYN=1; SEQ = 100SYN=1; SEQ = 100

SYN=1; SEQ = 200; ACK = 100 + 1 (101)

SYN=1; SEQ = 200; ACK = 100 + 1 (101)

SYN=0; ACK = 201; SEQ = 101

SYN=0; ACK = 201; SEQ = 101

Send dataSend data

AcknowledgeAcknowledge

station Astation Astation B

T I M E

Receipt of data

ISNSYN

SENT

LISTEN

SYN

RECEIVEDESTAB

SYN

SENT

ESTAB

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Connection Management

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Sequence Number & Acknowledgment


Ack=94

90

90

97

94

97

94

94

Ack=101101

90

Dealing with Errors (1/2)

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Sequence Number & Acknowledgment


Ack=97

90

90

94

94

90

9797

Ack=101101

90

Ack=97

Dealing With Errors (2/2)

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Window Management

Sender Receiver

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RetransmissionSegment 1Segment 1

ACK 1ACK 1

station Astation Astation Bstation B

RTTRTT

SRTTNew= x SRTTold + (1 - ) x RTT

Segment 2Segment 2

I’ll wait for RTO = x SRTT ms, but not more than UBOUND ms and not less than LBOUND ms.

If I don’t receive an acknowledgment, I’ll retransmit.

RTO = min [UBOUND, max (LBOUND, x SRTT)]

Segment 2Segment 2

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Flow Control

WINDOWWINDOWBB = 1000 = 1000

SEQ 2200 (1000 bytes)SEQ 2200 (1000 bytes)

SEQ 2200 (500 bytes)SEQ 2200 (500 bytes)

RTORTO

station Astation Astation B B

Congestion Window = Window B

Congestion Window = Congestion Window/2

Allowed Window = min (Window B, Congestion Window)

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UDP (User Datagram Protocol) is a connectionless protocol. It features high efficiency but it is not reliable.

TCP is mainly used to transfer large messages, such as FTP and TELNET while UDP is used to transfer small messages such as address inquiry and database inquiry. UDP’s reliability is ensured by the application program.

UDP is the upper layer of IP. Both of them are connectionless communication. Their difference is that UDP provides protocol port while IP provides host IP address.

Because UDP is connectionless communication, so it is unnecessary to establish or cancel connection or to have error check and flow control. UDP can be used to transfer data in real-time.

UDP

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UDP length: includes the 8-byte header and the data.UDP checksum is optional and stored as 0 if not computed.

source portUDP length UDP checksum

destination port

Data area

0 16 31

UDP header

UDP data

UDP header UDP data

IP header IP data

UDP message:

UDP Message Format

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IP Basic Concepts

IP Address

TCP/IP-IP Layer




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Internet Control Message Protocol (ICMP) is used to report messages or errors during datagram transmission.

ICMP uses the basic IP support as if it is a superior protocol. Actually ICMP is an integrated part of IP and each IP module should finish ICMP;

ICMP message is sent out in the following cases: (1) A datagram cannot reach its destination, (2) The router has no enough cache buffer to transmit datagram, or (3) The router can instruct the host to transmit datagram through a shorter path.

There are no ICMP messages about ICMP messages to avoid endless message-related messages;

ICMP messages only report the errors of No.0 segment.

ICMP

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Domain Name Resolution: Translate a domain name into an IP address; Application software uses domain name while TCP/IP uses IP address. Therefore, a domain name must be translated into the IP address for communication; The software for domain name resolution is called the domain name analyzer software. Each computer connected in the network is equipped with domain name analyzer software; Each domain name analyzer has the address of the local domain name server (DNS); As the client of DNS, the analyzer puts the domain name to be analyzed in the DNS application message, send it to the local DNS, and then waits for the server’s reply message that contains the domain name analysis.

DNS

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When an application needs to have domain name resolution, the application becomes the client of the DNS; The client places the domain name that is to be analyzed into the DNS application message and sends it to DNS; The server abstracts domain name from the application message, translates it into equivalent IP address and then sends it back to application through the reply message; DNS Hierarchical Structure: DNS is hierarchical to match the hierarchical structure of the same domain name; The root server is at the top of the hierarchical structure. It is authorized by the top-level domain. The root server contains information that arrives at other servers.

DNS

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DHCP provides various hosts with various configuration information to access TCP/IP;

For DHCP standard, please refer to RFC1541. It comes from BOOTP.

DHCP is in a client/server mode. The server has two major functions: to assign host IP address and transfer other network configuration parameters for the host.

Dynamic Host Configuration Protocol (DHCP)

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Contents

IP Basis

IP Transport in UMTS

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SCTP Functional Structure

SCTP user application

start & suspend

connection

stream sequential transmission

user data segmentation

confirm & avoid congestion

bind data blocks

verify packets

manage paths

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OMCB channel

Node B

Node B

RNCIP RAN

OMCB flow

OMCB Server(in RNC rack)

IP in IP tunnel

Use IP in IP tunnel to assure OMCB traffic must be transported through RNC

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OMCB Protocol stack and packet format

Node B Router RNC

IP(OMM)

OMCB

IP(OMM)

PHY

Ethernet

IP(OMM)

OMCB

PHY

Ethernet

IPOMMAgent

1 2

10.1.1.1

10.1.1.1

10.1.4.1

10.3.1.1 10.2.1.110.2.1.16

1122

Dest. IP10.3.1.1

Orig. IP10.1.1.1

Dest. IP10.2.1.16

Orig. IP10.1.1.1…….

Inner IP head Outer IP headData

1Dest. IP10.2.1.16

Orig. IP10.1.1.1…….

IP headData

2

Orig. IP10.3.1.1

Dest. IP10.1.1.1

Orig. IP10.2.1.16

Dest. IP10.1.1.1

…….

Inner IP headOuter IP head Data

2

PHY

Ethernet

PHY

Ethernet

IP

PHY

Ethernet

IP

PHY

IPRouting

Ethernet

IP

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DHCP Procedure In UMTSNode B Router

DHCP Discover (broadcast)

DHCP Offer (unicast)

RNC

DHCP Discover (unicast)

DHCP Offer (unicast)

Any broadcast/multicast (e.g. ARP, VRRP hello)

1

2 3

45

OMC-B Server

DHCP Request (broadcast)

DHCP ACK (unicast)

DHCP Request (unicast)

DHCP ACK (unicast)

6 7

8

9

10

Connect request

Connect response (IP in IP)

Connect request (IP in IP)

Connect response

Configuration download (IP in IP)

11

12 13

14

Connect requestConnect request (IP in IP)

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Course Review

Is 172.168.44.30/29 and 172.168.44.50/29 in the same subnet? And why? Describe the OMCB channel in IP mode.

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UMTS IP Bearer Basics

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