BICC protocol and application

1.01.0

BICC Protocol and Application

Objectives

• BICC application in R4 network

• BICC protocol structure and message introduction

• BICC signaling flow

Upon completion of this course,you will be able to:

Course Contents

OVERVIEW

BICC protocol introduction

Signal flow introduction

Examples

The Architecture of 3G R4

MGW

Signalling and Data Transfer Interface

Signalling Interface

UTRAN PSTN/ Legacy/External

HLR Applications & Services

MSC server GMSC server

Mc

D C

MGW Nb

Nc

Iu

Iu

CAP CAP

Mc

GERAN

A

A

BICC apply in the Nc interface

Basic concept

Outgoingprocedures

Incomingprocedures

BCF

Call Service Function (CSF)

BIWF

SERVING NODE (SN)

Bearer Control SignallingBearer Control Signalling

Bearer

SCOPE OF THISRECOMMENDATION

Call Control Signalling(BICC protocol or

other signallingsystem)

Call Control Signalling(BICC protocol or

other signallingsystem)

Call Bearer Control (CBC)signalling

Serving node:

Basic concept• SN types

– ISN : provides the interface with non-BICC networks and terminal equipment

– GSN : provides gateway functionality between two network domains

– TSN : provides transit functionality between ISNs and GSNs

Basic concept

Call Service Function (CSF)

Bearer Control Function (BCF)

Serving Node (SN)

Call Control Signaling (BICC protocol)

Call Control Signaling (BICC protocol)

Bearer Control Signaling Bearer Control Signaling

Bearer

Main scope of the BICC specification

Separation between call and bearer

Course Contents

OVERVIEW

BICC protocol introduction

Signal flow introduction

Examples

Network model of BICC

ISUP CC

BAT ASE

APM ASE BICC

ASE

BCF

Interface Serving Node (ISN)

CC

BAT ASE

APM ASEBICC

ASE

BCF

Transit Serving Node (TSN)

BAT ASE

APM ASE BICC

ASE

BCF

BICC signaling

Bearer control signaling

Bear Bear Bear

Bearerstreams

BICC protocol Model

• Signalling Transport Layer : MTP3 for TDM NetworkSCTP over IP for IP networkSSLOP for TAM network

• STC : Signalling Transport Converters. Mapping function according to underlying layers

SignallingTransport

Layers

BICC procedures

genericinterface

call controlprotocol

bearerspecificinterface

bearer controlprotocol

BearerControl

MappingFunction

genericinterface

transportspecificinterface

SignallingTransportConverter

Structure of the Protocol Stack

BICC

SCTP

IP

MAC

L1

(G)MSC ServerNc

MSC Server

c) SCTP/IP based

NcMSC Server

d) ATM based

(G)MSC Server

BICCBICC

SCTP

IP

MAC

L1

STC

SAAL

AAL5

MTP3B

ATM

PL

BICC

STC

SAAL

AAL5

MTP3B

ATM

PL

BICC

MTP3

MTP2

MTP1

(G)MSC ServerNc

MSC Server

a) TDM based

(G)MSC ServerNc

MSC Server

b) M3UA based

BICC

L1

BICC

M3UA

IP

MAC

L1

BICC

MTP3

MTP2

MTP1

SCTP

M3UA

IP

MAC

SCTP

BICC

SCTP

IP

MAC

L1

(G)MSC ServerNc

MSC Server

c) SCTP/IP based

NcMSC Server

d) ATM based

(G)MSC Server

BICCBICC

SCTP

IP

MAC

L1

STC

SAAL

AAL5

MTP3B

ATM

PL

BICC

STC

SAAL

AAL5

MTP3B

ATM

PL

BICC

MTP3

MTP2

MTP1

BICC

MTP3

MTP2

MTP1

(G)MSC ServerNc

MSC Server

a) TDM based

(G)MSC ServerNc

MSC Server

b) M3UA based

BICC

L1

BICC

M3UA

IP

MAC

L1

BICC

MTP3

MTP2

MTP1

BICC

MTP3

MTP2

MTP1

SCTP

M3UA

IP

MAC

SCTP

BICC Message StructureCIC

Message type code

Mandatory fixed part

Mandatory variable part

Optional part

Call Instance Code (CIC) is a logic number associated with

the inter-office calling relation

Format of BICC messages• CIC is used to identify signalling relation between peer BICC entities and associate all the PDUs to

that relation.

• message type code

• the mandatory fixed part

• the mandatory variable part

• the optional part, which may contain fixed length and variable length parameter fields

Blocking and Unblocking of CIC

• All outgoing non test calls are blocked using those CIC values

• Incoming non test call with those CIC leads to error case

• Incoming Test calls with those CIC values are permitted to be carried out

• Outgoing test calls using those CIC values are also permitted

Main message of BICC protocol

IAM ： Initial address messageAPM ： Application transport messageACM ： Address complete messageANM ： Answer message REL ： ReleaseRLC ： Release complete

Course Contents

OVERVIEW

H.248 protocol introduction

Signal flow

Examples

Chap3 signaling flow

3.1 BICC bearer establish mode3.1 BICC bearer establish mode

3.2 forward bearer establish

3.3 backward bearer establish

3.4 tunnel

3.5 CODEC negotiation

3.6 call release

Basic Call Setup• Forward Bearer Setup

No Tunnel caseFast Tunnel

Delayed Forward Tunnel

• Backward Bearer Setup No Tunnel CaseDelayed Backward Tunnel

Forward Bearer Setup• Bearer setup is initiated in the forward direction of the call

• CSF decides whether bearer setup will be in forward direction or in backward direction

• CSF decides if tunnelling is supported. BCF decides if tunnelling is used

• Tunnelling is carrying Bearer Control Info embedded in BICC messages


3.1 BICC bearer establish mode

3.2 forward bearer establish3.2 forward bearer establish


3.4 tunnel


3.6 call release

Forward Establish Flow

CSF

BCF-N

CSF

IAM (Action = Connect Forward), (BNC characteristics)

Bearer Set-up req. (BNC-ID=y1), (BIWF-Addr=y)

Bearer-Setup-Connect

IAM

ACM

ACM ANM

ANM

CSF-N

BCF-N

ISN-B

IAM (COT on previous), (Action = Connect Forward) , (BNC characteristics)

Bearer Set-up req. (BNC-ID=z1), (BIWF-Addr=z)


ACM

ANM

“BBB”

COT

APM (Action = Connect Forward, no notification) (BNC-ID=y1), (BIWF Addr=y)

APM (Action = Connect Forward, no notification) (BNC-ID=z1), (BIWF Addr=z)

BICC BICC

BCF-N (z) (y)

“AAA”

ISUP ISUP

ACM

ANM

(x)




3.3 backward bearer establish3.3 backward bearer establish

3.4 tunnel


3.6 call release

Backward Establish Flow

CSF-N

BCF-N (x)

CSF-T

IAM (Action = Connect backward), (BNC-ID=x1), (BIWF-Addr=x) , (BNC

characteristics)

Bearer Set-up req. (BNC-ID=x1), (BIWF-Addr=x)


IAM

ACM

ACM

ANM

ANM

CSF-N

BCF-N

IAM (Action = Connect backward), (COT on previous), (BNC-ID=y1), (BIWF-

Addr=y) , (BNC characteristics)

Bearer Set-up req. (BNC-ID of BIWF y), (BIWF-Addr=y)


ACM

ANM

“BBB”

COT

BICC BICC

BCF-N (y)

“AAA”

ISUP ISUP

ACM

ANM

(z)





3.4 tunnel3.4 tunnel


3.6 call release

Tunnel• Bearer Setup Messages (IPBCP) are sent embedded in BICC messages

• Fast Tunnel : Tunnel data transferred in first IAM message

1: Tunnel Info

5: APM (tunnel data)

2: IAM (tunnel data)

4: Tunnel Info 6: Tunnel Info 3: Tunnel Info

CSF

BCF

CSF

BCF

Tunnel Contd…• Forward Delayed Tunnel : Tunnel data not transferred in first IAM message or in

first backward APM message , Starts from first forward direction APM message

3: Tunnel Info




CSF

BCF

CSF

BCF



Tunnel contd…• Backward Delayed Tunnel : Tunnel data not transferred in first IAM message , but

starts from first APM message in backward direction

6: Tunnel Info




CSF

BCF

CSF

BCF





3.4 tunnel

3.5 CODEC negotiation3.5 CODEC negotiation

3.6 call release

Codec Negotiation• The Supported Codec List is constructed and contains all the codecs, in priority order, that are

offered for use in the call from the SN initiating codec negotiation.

• Intermediate SN will delete the codecs from the received Supported Codec List which it cannot support and is passed to next SN

• Terminating SN selects the codec with highest priority in the received Supported Codec List that can be supported by it. This is selected codec. This is passed to previous SN.

Codec Negotiation contd.

CSF-N

BCF-N (x)

ISN-A

CSF-T

TSN

IAM (Action = Connect backward), (Codec list) (BNC-ID=x1), (BIWF-Addr=x) , (BNC

characteristics)

Bearer Set-up req. (BNC-ID=x1), (BIWF-Addr=x)


IAM

ACM

ACM

ANM

ANM

CSF-N

BCF-N

ISN-B

IAM (Action = Connect backward), (Codec list) (COT on previous), (BNC-ID=y1), (BIWF-

Addr=y) , (BNC characteristics)

Bearer Set-up req. (BNC-ID=y1), (BIWF-Addr=y)

Bearer-Setup-Connect ACM

ANM

BICC BICC

BCF-N (y)

“AAA”

ISUP ISUP

ACM

ANM

(z)

APM (Action = Selected codec), (Selected codec), (Available codec list)

APM (Action = Selected codec), (Selected codec), (Available codec list)





3.4 tunnel


3.6 call release3.6 call release

Release• CSF receiving REL, initiates bearer release towards the sender of REL if

this CSF initiated bearer setup before and then sends back RLC

• CSF sending REL to the other CSF, waits until it gets RLC and then initiates bearer release towards the sender of RLC, if this CSF initiated bearer setup before

Release while forward bearer establishment

CSF-N

ISN-A

CSF-T

TSN

CSF-N

ISN-B BICC BICC

REL

REL REL

REL

BCF-N

RLC

RLC

RLC RLC

Bearer release req.

Bearer release Ack.

BCF-N BCF-N

Bearer release Ack.

Bearer release Req.

ISUP ISUP

Release while Backward bearer establishment

CSF-N

ISN-A

CSF-T

TSN

CSF-N

ISN-B BICC BICC

REL

REL REL

REL

BCF-N

RLC

RLC

RLC

RLC Bearer release req.

Bearer release Ack.

BCF-N BCF-N

Bearer release req.

Bearer release Ack.

ISUP ISUP

Course Contents

OVERVIEW

H.248 protocol introduction

Signal flow

Examples

Example of call setup in caller MSC Server, Forward no tunnel case

666 CC BICC MGRM STC

Setup (Forward, no tunnel, no MGW ID, Initiator)

IAM (connect forward, no tunneling control info IE is present, COT to be expected)

Setup Ack APM(Connect forward, plus notification, BNC id, BIWF address,succeeding MGW-ID)

Bearer Establish (MGW-ID2,no tunneling supported, send/receive, BNC id, BIWF addr)

Info (context id/context id2, termination id)

Bearer Establish Ack ( no tunneling, context id, termination id)

Info (MGW_ID1, MGW ID2)

Info (APM Ind, BIWF address succeeding MGW-ID)

Bearer Established

Bearer Prepare ( MGW-ID2, context id) (when MGW-ID1

<>MGW-ID2，execute internal connection)

Bearer Prepare Ack (context id, termination id, MGW-ID2 address)

Bearer Establish (MGW-ID1,MGW-ID2 address)

Bearer Esstablish (context id2 termination id, MGW-ID2 address)

Example of call setup in MSC Server contd.

666 CC BICC MGW_RM STC

Continuity

COT

ACM Alerting

Answer

Connect Ack

ANM

APM (Connected) << is sent only plus notification>>

Few CBC Methods used for Codec negotiation and codec modification

• Reserve Char to reserve the necessary resources for all specified bearer service characteristics or codecs.

• Confirm Charto confirm one particular codec or one bearer service characteristics to be used and others resources if allocated previously to be released

• Modify Charto change a codec or a bearer service characterstics

Backward bearer setup with Codec Negotiation in caller MSC

CC BICC MGW_RM STC

Setup (MGW-ID1,MGW-ID2, backward, no tunnel,codec list, init iator

IAM (connect forward, BIWFaddress, BNC id, no tunnelingindication)

Info (context id,termination id1 )

Bearer Prepare ( no tunnelsupport, codec list , send/receive,context id)

Bearer Prepare Ack(no tunnel,termination id2, BNC id, BIWF addr)

ACM

Alerting

AnswerANM

Setup Ack

Info (context id,termination id2

APM (connect backward selectedcodec, available codec list)

Confirm Char(selected codec)

Confirm Char AckInfo (selected codec,available codec list)

Continuity

COT

Release of Call• Outgoing side while bearer setup was forward • Incoming side while bearer setup was in

the forward direction

CC BICC STC

Release

Release bearer

Release bearer Ack

Release Complete

MGW_RM

REL

RLC

CCBICCSTC

Release

MGW_RM

REL

Release CompleteRLC

Termination ReleaseAck

Termination Release

Bearer Released

BICC protocol and application

Technology

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