03-TN_SP002_E1_1 Iu Interface and Sigtran Protocol-35

8/10/2019 03-TN_SP002_E1_1 Iu Interface and Sigtran Protocol-35

1/35

TN_SP002_E1_1

Iu Interface and Sigtran overview

V1026


2/35

Course Objectives

Function of Iu interface

RANAP protocol overview

SigTran Protocol


3/35

lu Interface

Iu-CS Iu-PS

AuC

GGSN

InternetPSTN

Other

PLMN

SGSN GSN

Node B Node B

RNC

GbA

Gs

Gr

Gn

GcC

D

Gp

Iub

BTS BTS

BSC

Abis

UmUu

RNC Iur

CS PS

Node B

Iub

Nb

Nc

MGW

GMSC

Server

Mc

MSCServer/

VLR

Mc

H

HLR

MGW

Gi


4/35

lu Interface Functions

The creation, maintenance and release management ofRAB

Implementing the switching between systems and within a

system

Support of cell broadcast service The general management process without relationship with

the subscribers

User signaling management

Support of location services Support of the simultaneous access into different domains

of the CN by the subscribers

Security function


5/35

PS Protocols

Structure of Iu-PS Interface used ATM

Physical Layer

ATM

AAL 5

SSCF-NNI

SSCOP

RANAP

Radio

Network

Layer

Transport

Network

Layer

Control Plane

Transport Network

Control Plane

User Plane

Iu UP Protocol

Layer

MTP3-B

SCCP

Transport Network

User Plane

Transpo

rt Network

User Plane

Physical Layer

ATM

AAL 5

UDP

IP

GTP-U


6/35

PS Protocols

Structure of Iu-PS Interface used IP

Physical Layer

Datalink

IP

RANAP

Radio

Network

Layer

Transport

Network

Layer

Control Plane

Transport Network

Control Plane

User Plane

Iu UP Protocol

Layer

SCTP

SCCP

Transport Network

User Plane

Transpo

rt Network

User Plane

Physical Layer

Datalink

IP

UDP

GTP-UM3UA


7/35

Iu UP ProtocolLayer

User Plane

User Plane

AAL5

IPUDP

GTP-U

Iu UP ProtocolLayer

User Plane

AAL2

STC Q.2150.1

ALCAP Q.2630.1

Control Plane

AAL5

SSCOP

SSCF-NNI

MTP3b

User Plane

Establishconnection

Physical Layer

ATM

Transport

NetworkLayer

RANAP

Control PlaneRadio

Network

Layer

Iu Interface


8/35

Course Objectives



SigTran Protocol


9/35

RANAP Protocol

(Radio Access Network Application Part)

RANAP

According to transport

of message ways, it is

divided into connection

oriented and

connectionless

For interaction ways,it is

divided into three types:

with answer, without

answer and multiple

answer

Responsible for functions of signal

interaction and encapsulation of Iu

interface and higher protocol bearer


10/35

Security mode

control function

SRNS contexttransferprocess Traffic report

process

Location report

process:Paging process

Iu interface

release

process

Relocation

process

RABassignment

function

Functions of RANAP

RANAP Function


11/35

RANAP: Initial UE Message

Iu signaling connection initialization (Initial UEMessage)

This process is used by RNC to forward NAS-PDU

from UE to CN transparently when Iu signaling

connection is established by RNC , it belongs tono response and connection oriented process.

CNRNC

Initial UE Message


12/35

RANAP: RAB Assignment

RAB Assignment is initiated by CN, but CN onlyassign RAB ID and related RAB parameters, RNC

is responsible for execution and assigning user

plane resources and respond with one or more

responses to CN.CNRNC

RAB Assignment Request

RAB Assignment Response


13/35

RANAP: Paging

This process is used for CN to send pagingmessage for certain UE, it belongs to no response

and connectionless process. When UE is in idle

mode, public paging channel is used for paging;

When UE already has RRC (Radio ResourceControl) , specified RRC connection will be used

for paging.

CNRNC

PAGING


14/35

RANAP: Iu Release

This process is used to release Iu connection andrelated resources of UTRAN part, it has response

and is connection oriented.

CNRNC

Iu Release Command [Cause]

Iu Release Complete

Iu Release Request


15/35

Course Objectives



SigTran Protocol


16/35

Definition

SIGTRANSignaling TransportSIGTRAN isused to transfer SS7 signaling in IP network. The

standard primitive interface supported by the

SIGTRAN does not require any modification to the

application part of the SS7. It transfers SS7signaling over standard IP transport protocol and

adds functions to meet the transport requirements

of the SS7 signaling.


17/35

Transport

Adaptation

IP layer

Application

SIGTRAN Protocol Structure

IP

S TP

IUA M2UA/M2PA M3UA SUA

Q931/QSIG MTP3 TUP ISUP SCCP TCAP

TCAP

SigTran Protocol contains two layers: Transport layerandAdaptation layer


18/35

SCTP Protocol

The Stream Control Transmission Protocol (SCTP)is designed to transfer SCN narrowband signaling

messages over the IP network. Actually the SCTP

is a connection-oriented protocol, but the concept

of the SCTP association is broader than that of theTCP connection.

SCTP is a reliable datagram transfer protocol

based on an unreliable transfer protocol such as

UDP.


19/35

SCTP Terminology

Host: it is a physical entity, e.g. one computerconfigured with one or more IP addresses.

SCTP End Point: it is a logical entity, e.g.

datagram sender and receiver. Each end point isjust identified by IP address and port number,similar to TCP.

SCTP Association: it is a logical association orchannel established between two SCTP EndPoints. C/S mode is adopted.


20/35

SCTP user

SCTP layer

IP layer One or more IP addresses

Network transferSCTP end oint A SCTP endpoint B

SCTP user

SCTP layer

IP layer

SCTP Layer model


21/35

SCTP Initiation Procedure

The SCTP initiation procedure relies on a four-message sequence:

INIT, INIT ACK, COOKIE ECHO, COOKIE ACK.


22/35

SCTP Features

Features of SCTP: Supporting sequenced or unsequenced transfer of user

datagram within the stream;

Establishing multiple streams within an association, and

the transfer of the data between the streams isindependent;

Supporting multi-homing at either or both ends of the

association to improve the reliability of the association;

Using COOKIE authentication to ensure the security ofthe association setup;


23/35

Adaptation Protocols

According to the different upper users, differentadaptation protocols are adopted.

M3UA

M2UA

M2PA

SUA


24/35

Adaptation Layer-M3UA

M3UA (MTP3-User Adaptation Layer) protocolconducts conversion between SPCs and IP

addresses. It is used for the SS7 signaling transfer

between the SGSN and the RNC. It supports

transferring the MTP3 user messages over the IPnetwork, including ISUP, TUP, and SCCP

messages.


25/35

M3UA Terminology Introduction

AS (Application Server): AS is a logical conceptand relevant to a physical equipment.

ASP (Application Server Process): ASP is a

progress instance. The AS contains a set of one

or more unique ASPs, of which one or more isnormally actively processing traffic.

In our system, we can have more than 1 ASP to

server an AS.


26/35

M3UA Terminology Introduction

IP Server Process (IPSP): it is the processinstance based on IP application. Essentially,

IPSP is the same as ASP but SCTP just uses the

end-to-end service.


27/35

IP

SCTP

ISUP

M3UA

IPSP

IPIP

SCTP

ISUP

M3UA

IPSP

M3UA occurred in IPSP


28/35

Adaptation Layer-M2UA

M2UA: The MTP2 user adaptation layer (M2UA)terminates the MTP2 at the edge SG of the

packet-based network, and transparently transfers

MTP2 user messages (MTP3 messages) to the

MTP3 in the packet-based network.


29/35

L1

MTP2

MTP3

L1

MTP2

(NIF)

M2UA

IP

SCTP

MTP3

M2UA

SCTP

IP

SP SG ASP

SS7 IP

M2UA in SG


30/35

Adaptation Layer-M2PA

M2PAM2PA is used to support the operationsbetween the peer layers of the MTP3 in the IP

network, support the boundary interface between

the MTP2 and MTP3, support the message

transfer through the SCTP association, implementthe MTP2 link function, and report the change to

the management status.


31/35

L1

MTP2

MTP3

L1

MTP2

MTP3

M2PA

IP

SCTP

MTP3

M2PA

SCTP

IP

SP SG ASP

SS7 IP

M2PA in SG


32/35

IP

SCTP

MTP3

M2PA

IPSP

IPIP

SCTP

MTP3

M2PA

IPSP

M2PA in IPSP


33/35

Adaptation Layer-SUA

SUA: The SUA defines how to transfer SCCP usermessages between two SPs through IP. It can be

used by the SG for the interworking between the

SS7 and IP; it can also be used for the

interworking between two IPSPs in the IP network.


34/35

L1

MTP2

TCAP

L1

NIF

SUA

IP

SCTP

TCAP

SUA

SCTP

IP

SP SG ASP

SS7 IP

MTP3

SCCP

MTP2

MTP3

SCCP

SUA in SG


35/35

Documents

03-TN_SP002_E1_1 Iu Interface and Sigtran Protocol-35