3G All IP Networkacpang/course/voip_2005/... · 2005-05-31 · 6 SGSN and GGSN IP based Network...

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3G All IP Network

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Outline

Mobile Technology EvolutionGPRS Overview3GPP UMTS System (Release 99)Introduction to VoIP Technologies• H.323• SIP• MGCP/MEGACO• SIGTRAN• Softswitch

3GPP All IP Network

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Mobile Technology Evolution

1G – Analog System• AMPS (Advanced Mobile Phone System) : 中華電信090系統

2G – Digital System• GSM (Global System for Mobile Communication)

900MHz and 1.8GHz (DCS1800)TDMA and FDMA Technologies9.6K bps Data Rate (Shore Message Service; SMS)歐亞160 Countries, 全球55%市場, 約5億個用戶

• CDMA (Code Division Multiple Access)IS-95: Data Rate 14.4K bps (cdmaOne) IS-95B: Data Rate 64 KbpsQualcom亞太北美市場, 約7,500萬用戶

• D-AMPS又稱IS-136

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2.5G

GSM System• High Speed Circuit Switch Data (HSCSD)

Up to 115.2 Kbps

• General Packet Radio Service (GPRS)Up to 171.2 Kbps

• Enhanced Data rates for GSM Evolution (EDGE)改變調變技術

up to 384 Kbps (Also considered as 3G technology)D-AMPS EDGE

cdma System• cdma 1x

Up to 144 KbpsKorea

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GPRS SystemPacket Switching TechnologyBased on GSM Cellular NetworkHigh Data Speed• 21.4 Kbps per Time Slot (channel)• Up to 8 Time Slots

GPRS

ExternalData

Network

PSTN

HLR

SGSN GGSNGb

Gn Gi

GSM

PCU

BSS

GatewayMSC/VLR

VisitedMSC/VLR

Physical Channel for Data Transmission• Assigned on Demand• Can Be Shared with Other Users

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SGSN and GGSN

IP basedNetwork

SGSN GGSNHLR

Serving GPRS Support Node. Mobility Management (Location

Update, Paging etc.). Access Control & Security (Authentication, Ciphering)

. BSS Queue Management

. GSM Circuit-Switched Interactions

. Operation Data, such as Billing Info.

Gateway GPRS Support Node. Interworking between PDN andGPRS PLMN

. Packet Screening

. Routing Tables about Attached GPRS Subscribers

. Address Mapping

. PDU Tunneling

. Operation Data, such as Billing Info.

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GPRS MM/SM

Mobility Management• Attach• Detach• Security• Routing Area Update

Session Management• PDP Context Activation• PDP Context Deactivation• PDP Context Modification

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3GIMT-2000• Year 2000 Ready• Operate at 2000 MHz• Provide 2000K bps Data Rate

3G Data Rate 要求• Vehicular -- 144 Kbps• Pedestrian --- 384 Kbps • Indoor --- 2Mbps

Three Important 3G Technologies Standards• W-CDMA (Wideband CDMA) (歐日系統)

GSM/GPRS/EDGE W-CDMA• cdma2000 (北美系統)• TD-SCDMA (Time Division Synchronize CDMA) (大陸系統)

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From 2G to 3G

From Voice Service to Rich, Interactive Multimedia-based Personal Communication ServicePermanent Network Connection with High Data Rate• 384 Kbps to 2 Mbps• Mobile Aaccess to High-quality Video, Audio, Graphics and

Multimedia as Fixed Internet

Massive Increase in Network Capacity• To Support Billions of Subscribers

Global Roaming• To Use Single Terminal to Access Identical Services All Around

the World

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3GPP UMTS System

Node B

Node B

Node B

Node B

RNC

RNC

Iub Iur

UTRAN

USIM

ME

UE

Cu

3G MSC/VLR

3G SGSN

GMSC

GGSN

HLR

External Networks

PLMN,PSTN, ISDN,...

Internet

Core Network

Uu Iu

Iu-PS Gn Gi

GrGc

D D

System Architecture of 3GPP Release 99

Gs

Iu-PS

Iu-CS

Iu-CS

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VoIP Protocols

H.323SIP (Session Initiation Protocol)MGCP (Media Gateway Control Protocol) MEGACO (Media Gateway Control Protocol)

SIGTRAN (Signaling Transport)Softswitch

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What is H.323

The H.323 standard provides audio, video and datacommunications across IP-based networks.H.323 is an umbrella recommendation from ITU, which was approved in 1996.

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PictureTel

RAS Channel

1. ARQ (alias address/bandwidth)2. ACF (call signaling channel address/bandwidth)

5.ARQ

6.ACF

3. Setup

Q.931 Call Signaling Channel

4. Call Proceeding

Gatekeeper

Terminal B

PictureTel

Terminal A

7. Alerting8. Connect (H.245 Address)

H.245 Control Channel

Capability ExchangeOpenLogicalChannel

OpenLogicChannelACK

Logical Channel (RTP Stream)

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What is SIP

Developed in IETF• Proposed standard RFC 2543, February 1999• Current standard: RFC 3261

Main functions• Invite users to sessions

Find the user’s current location, match with their capabilities and preferences

• Modification of sessions• Termination of sessions

Text-based Encoding

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SIP Architecture

User Agent Client(Calling Party)

Proxy ServerProxy Server

Proxy Server

Redirect Server

Location Server

SIP RequestSIP ResponseMedia Stream

User Agent Server(Called Party)

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Invitation for SIP Proxy Server

itri.org.tw

location server

BENZ

honda@AUDI

(5)

AUDI(1) [email protected]

[email protected]

csie.nctu.edu.tw

BMW(2

) hon

da

(3) h

onda

@A

UD

I

(4) INVITEhonda@AUDI

(5) 200 OK(6) 200 OK

(7) ACK [email protected]

(8) ACK honda@AUDI

RTP Stream

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Invitation for SIP Redirect Serveritri.org.tw

location server

BENS

AUDI

Honda@AUDI

[email protected]

csie.nctu.edu.tw

BMW

(2) h

onda

(3) h

onda

@A

UD

I

(4) 302 Moved temporarilyContact: [email protected]

(5) ACK [email protected]

(1) INVITE [email protected]

(6) INVITE [email protected]

(7) 200 OK(8) ACK [email protected]

RTP Stream

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Class 5 End Office Switch

The Telephone Network [1/2]

Circuit Switched Network

Intelligent Peripheral

Signal Transfer Point

Service Control Point

Class 4 Tandem Switch

Service Data Point

+

Transport Layer

Control Layer

SS7 SignalingISUP MessagesINAP/TCAP Messages

Reference: CCL/ITRI

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The Telephone Network [2/2]5 Basic Components in Intelligent Networks• SSP/Service Switching Point

switching, signaling, routing, service invocation

• STP/Service Transfer Pointsignaling, routing

• SCP/Service Control Pointservice logic execution

• SDP/Service Data Pointsubscriber data storage, access

• IP/Intelligent Peripheralresources such as customized voice announcement, voice recognition, DTMF digit collection

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Introduction to MGCP/MEGACOA protocol for controlling media gatewaysTwo components• Media gateway provides conversion between audio

signals on telephone circuits and data packets carried over IP networks.

• Call agent (Media gateway controller) handles the call setup and release for media channels in a media gateway.

Types of media gateway• Trunking gateway to CO/switches• Residential gateway to PSTN phones

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MGCP/MEGACO-based Architecture

Signaling(SS7)

Gateway

TrunkingGateway

CallAgent

SCP

ResidentialGateway

InternetSS7 Network

STP

TrunkingGatewayTrunking

GatewayCO

Switch

ResidentialGatewayResidential

Gateway

MGCP/MEGACO

RTP

SIGTRAN MGCP/MEGACOPSTN

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SIGTRAN

IETF SIGTRAN (Signaling Transport) - for SS7 over IP

ISUPTCAP

SCCP

MAP

MTP

OSI Layers

Application

PresentationSession

Transport

Network

Data Link

Physical

INAP

SS7 Protocol Stack

ISUPTCAP

SCCP

MAP

SCN Signaling Adaptation(SSA)

Common SignalingTransport (CST)

IP

INAP

SIGTRAN Protocol Stack

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Softswitch Overview [1/2]

Softswitch: Emulating Circuit Switching in Software

IN/SCP

PSTNLocal Switch

PSTNLocal Switch

STP SS7 Network

IP Network

RTP Streams

MGCMGC MGCMGC

Trunk Trunk GatewayGateway

Trunk Trunk GatewayGateway

SIP-T

SGSGSGSG

SIGTRAN

MEGACO

IP PhoneIP Phone

90009000 Personalized VoIPService System

Application ServerApplication ServerReference: CCL/ITRI

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Softswitch Overview [2/2]

Softswitch Provides Open Layered Architecture

• Solutions in a proprietary box• Expensive• Little room for innovation

Circuit-Switched

TransportHardware

Call Control & Switching

Services & Applications

PROPRIETARY

• Solutions are open standards-based• Customers choose best-in-class products • Open standards enable lower cost for innovation

Soft-Switched

Transport Hardware

Softswitch Call Control

Services, Applications & Features (Management, Provisioning and

Back Office)

Open Protocols APIs

Open Protocols APIs

Open APIs for 3rd Party App develop.

Best-in-class Access Devices.

Scalable, Open Interfaces for Comm.

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Softswitch Architecture

SIP-T

COSwitch

STP

SCP

COSwitch

STP

SCP

Signaling Layer

Transport Layer

IP

MediaServer

RTP

SIP-?

SIP-TSI

Media Gateway

Controller

TrunkingGateway

Signaling(SS7)

GatewayMedia

GatewayController

ResidentialGateway

SIGTRAN

RTP

SS7 TCAP

MGCP/MEGACOPhones

ISUP/TCAP

App.Server

MGCP/MEGACO

Reference: CCL/ITRI

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3GPP All IP Network

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All IP Architecture

Based on packet technologies and IP telephony for real time and non real time servicesAn evolution from Release 99 specifications• All IP core network should support release 99 CS

terminalsRadio Access Network (RAN) • GERAN and UTRAN

Core Network• Based on the evolution of GPRS

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3GPP All IP Network

RNC

Node B

Node B

MS

MS

SGSN

T-SGW

Internet

PSTN

MSC Server

GGSN

Legacy mobilesignaling network

CSCFHSS

MGWMGW

GMSC Server

R-SGW

MAP

MAP Mc

McGi

Gi

Nc

Nb

Iu_CS(control part)

Mh

Gr Gc

Cx

Mm

Ms

GnIu_PS

Iu_CS(user traffic)

Gi

Mc

MGCF

Mg

Gi

MrMRF

Signaling (SS7 or IP based)Circuit

Packet (user traffic / signaling)

Call control function

Reference: CCL/ITRI

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Circuit-Switched Services

RNC

Node B

Node B

MS

MS

T-SGW

PSTN

MSC Server


HSS

MGWMGW

GMSC Server

R-SGW

MAP

MAP Mc

Nc

NbIu_CS

(control part)

Mh

Gr

Iu_CS(user traffic)

Mc




Reference: CCL/ITRI

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Packet-Switched Services

RNC

Node B

Node B

MS

MS

SGSN InternetGGSN

HSS

Gi

Gr Gc

GnIu_PS

Gi




Reference: CCL/ITRI

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Real-Time PS Services

RNC

Node B

Node B

MS

MS

SGSN InternetGGSN


CSCFHSS

R-SGW

Gi

Mh

Gr Gc

Cx

Mm

Ms

GnIu_PS

GiMg

Gi

MrMRF




Reference: CCL/ITRI

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Interworking with PSTN

RNC

Node B

Node B

MS

MS

SGSN

T-SGW

Internet

PSTN

GGSN


CSCFHSS

MGW

R-SGW

McGi

Gi

Mh

Gr Gc

Cx

Mm

Ms

GnIu_PS

Gi

MGCF

Mg

Gi

MrMRF




Reference: CCL/ITRI

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HSSHSS (Home Subscriber Server) is the master database for a given user.Functionalities• The HLR functionality required by the PS-Domain• The circuit switched part of the HLR• User control functions required by the IP multimedia

(IM) subsystem

HSS

MSC Server GMSC Server SGSN GGSN R-SGW CSCF

D C Gr Gc Mh Cx

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CSCF [1/4]

Call State Control FunctionICGW (Incoming Call Gateway)

• Acting as a first entry point to perform routing of incoming calls

CCF (Call Control Function)• Call setup/termination and call state/event management• Application level registration handling

SPD (Serving Profile Database)• Interacting with HSS to receive user profile information

AH (Address Handling)• Mapping between alias address (e.g., E.164 number) and

transport address

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CSCF [2/4]

Proxy CSCF (P-CSCF) is the first contact point within IM CN subsystem.• Its address is discovered by UEs following PDP

context activation procedure.• Behaving like a Proxy server defined in RFC2543

P-CSCF Discovery• Use of DHCP (Dynamic Host Configuration Protocol)• Transfer the P-CSCF address with the PDP Context

Activation signaling to the UE

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CSCF [3/4]

Serving CSCF (S-CSCF) performs the session control service for the UE.

• Maintaining a session state as needed by the network operator for support of the services

Registration• Behaving as a Registrar as defined in RFC2543• It accepts registration requests and makes its

information available through the location server (e.g., HSS).

Session Flow• Interaction with service platform for support of

services

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Service Platform Interface

SIP ApplicationServer

CAMEL ServiceEnvironment

SIP+

OSA APICx

IM SSF

SIP+

OSAApplication

ServerS-CSCF

OSA ServiceCapability Server

(SCS)HSS

SIP+

CAP

MAP

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CSCF [4/4]

Interrogating CSCF (I-CSCF) is the contact point within an operator’s network for all connections destined to • a subscriber of that network operator, or • a roaming subscriber currently located within that network

operator’s service area.• That is,I-CSCF is the first contact point within an operator’s

network for incoming call signaling.Registration• Assigning a Serving CSCF to a user performing SIP

registrationSession Flow• Routing a SIP request received from another network

towards the S-CSCF(Serving Terminating UE)• Obtaining the S-CSCF address from HSS

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MGCF & MGW

Media Gateway Control Function• Being PSTN signaling termination point• Performing protocol conversion between the legacy

(e.g., ISUP) and the All-IP network call control protocols

Media Gateway• Being PSTN transport termination point• Interfacing UTRAN over Iu

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MSC Server

Mainly comprising the call control and mobility control parts of a GSM/UMTS MSCPerforming the connection control for media channels in a MGWMSC server + MGW = MSC

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MRF

Multimedia Resource Function• Performing multi-party call and multimedia

conferencing functions• The same function as an MCU in the H.323

network

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T-SGW & R-SGW

Transport Signaling Gateway Function• Mapping call related signaling from PSTN/PLMN on

an IP bearer and sending it to the MGCF• Providing PSTN/PLMN↔IP transport level address

mappingRoaming Signaling Gateway Function• Providing communication with a 2G/R99 MSC/VLR

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IM Subsystem

IP Multimedia (IM) CN subsystem• Comprising all CN elements for provision of

multimedia servicesThe IM subsystem (IMS) utilizes the PS domain to transport multimedia signaling and bearer traffic.The IMS attempts to be conformant to IETF “Internet standards”.• SIP (Session Initiation Protocol) has been selected

as the interfaces between the IM CN elements.

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Registration

UE GPRSIP MM CN Subsystem

1. Bearer Level Registration: GPRS

2. PDP Context Activation

3. P-CSCF Discovery

4. Application Level Registration

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Application Level Registration

I-CSCFP-CSCFUE HSS1. Register

S-CSCF

Visited Network Home Network

2. Register3. Cx-Query3. Cx-Query Resp.

4. Cx-Select-Pull4. Cx-Select-Pull Resp.

5. Register

6. Cx-Put

6. Cx-Put-Resp.

7. Cx-Pull

7. Cx-Pull-Resp.8. 200 OK

9. 200 OK10. 200 OK

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Call Setup Diagram

S-CSCFS-CSCF

P-CSCFP-CSCF

GGSNGGSNSGSNSGSN

Radio Access NetworkRadio Access Network

I-CSCFI-CSCF

HSSHSS App.Server

3

1

2

Originating Home Network

Visited/HomeNetwork

S-CSCFS-CSCFI-CSCFI-CSCF

HSSHSS

5 6

7

8

Terminating Home Network

4

P-CSCFP-CSCF

GGSNGGSNSGSNSGSN

Radio Access NetworkRadio Access Network

10

9

App.Server

Originating Terminating

Visited/HomeNetwork

Reference: CCL/ITRI

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Session Flow Procedure

UE#1 S-CSCF#1 S-CSCF#2 UE#2

INVITE

Ringing

200 OK

ACK

SDP

Final SDPReserv Success

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INVITE

P-CSCFP-CSCF

Home Network#1

INVITE+SDP

INVITE + SDP

I-CSCF#2 HSS S-CSCF#2S-CSCF#1

Home Network#2

UE#2

INVITE + SDP

Service Control

INVITE + SDP

Location QueryResponse

INVITE + SDP

INVITE + SDP

100 trying

100 trying

100 trying

100 trying

100 trying

100 trying

Service Control

UE#1

Visited Network#1 Visited Network#2

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183 Session Progress + PRACK

P-CSCFP-CSCFUE#1

Home Network#1Visited Network

I-CSCF#2 HSS S-CSCF#2S-CSCF#1 UE#2183 (SDP)

183 (SDP)183 (SDP)

183 (SDP)183 (SDP)

183 (SDP)

PRACK (Final SDP)

PRACK (Final SDP)PRACK (Final SDP) PRACK (Final SDP)

200 OK200 OK

200 OK 200 OK

Authorize QoS Resource

Authorize QoS Resource

200 OK

PRACK (Final SDP)

Home Network#2 Visited Network#2

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Reserv Success (COMET)

P-CSCFP-CSCFUE#1


COMET

I-CSCF#2 HSS S-CSCF#2S-CSCF#1 UE#2

COMET

COMETCOMET

COMET

200 OK

200 OK 200 OK

200 OK200 OK

Resource Reservation

ResourceReservation


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Ring (180 Ringing) + 200 OK (Hang Up) + ACK

P-CSCFP-CSCFUE#1


I-CSCF#2 HSS S-CSCF#2S-CSCF#1 UE#2Ring

RingRing

RingRing

Ring

Ringback

200 OK

200 OK

Service Control

200 OK 200 OKService Control

ACK

ACK

ACK ACKACK

200 OK

200 OK

Approval of QoS Commit

Approval of QoS Commit


3G All IP Networkacpang/course/voip_2005/... · 2005-05-31 · 6 SGSN and GGSN IP based Network...

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Transcript of 3G All IP Networkacpang/course/voip_2005/... · 2005-05-31 · 6 SGSN and GGSN IP based Network...