Voip Mgcp Ds

VOIP Introduction -MGCP

UTStarcom Confidential

Topics

Topics VOIP Introduction MSAN VOIP module introduction Basic Voip Service Provision


What is MGCP

Media Gateway Control Protocol - A protocol for controlling media gateways from external call control elements called media gateway controllers or call agents.

IETF RFC 3435 Media Gateway Control Protocol


What is MGC and MG Media Gateway Controller (MGC): Central point of intelligence for call signaling Maintains the state of each MG and responds appropriately to any event notification Media Gateway (MG): Provides translations between circuit switched networks and packet switched networks Sends notification to the call agent about endpoint events Execute commands from the call agents


Soft Switch Architecture-MGC, MG


VOIP Network Architecture

SS7 NetworkSCP STP

Signaling (SS7) Gateway SIGTRAN

InternetCall Agent MGCP/ MEGACO

MGCP/ MEGACO Trunking Trunking Gateway Trunking Gateway Gateway

CO Switch

RTP

Residential Residential Gateway Residential Gateway Gateway


MGCP in the protocol stack Call Control and SignalingH.323 H.225 H.245 Q.931 RAS SIP MGCP/Megaco RTP RTCP RTSP

Signaling and Gateway Control

MediaAudio/ Video

TCP IP

UDP

MGCP UDP port could be 2427 or 2727


Protocol Evolution

IPDC

MGCP proposal by merging IPDC and SGCP

SGCP

MGCP

RFC 2705/3435

Lucent submits MDCP to ITU-T SG16 (Nov 1999)

MDCP(proposal) Consensus between IETF and ITU on Megaco Protocol (March 99)

Megaco/H.248

IETF RFC 3015/3525


Characteristics A master/slave protocol. Assumes limited intelligence at the edge (endpoints) and intelligence at the core (call agent). Used between call agents and media gateways. Differs from SIP and H.323 which are peer-to-peer protocols. Text encoding Use ASCII. Use SDP to describe the media SDP Session Description Protocol RFC2327 Description of connection parameters such as IP addresses, UDP port and RTP profiles Packages define extensions Modular and extensible protocol, achieved by the concept of packages Many defined in RFC3660, e.g. Line package (L),DTMF package (D)UTStarcom Confidential

The MGCP Model Endpoints Sources or sinks of media Trunk interfaces POTS line interfaces Announcement endpoint Connections Allocation of IP resources to an endpoint An ad hoc relationship is established from a circuited-switched line and an RTP port on the IP side. A single endpoint can have several connectionsUTStarcom Confidential

Function of MGCP The primary function of MGCP is to enable

The connections to be created The session descriptions to be exchanged between the connections


Example MGCP Message


MGCP key point--Endpoint Identifier (1) Domain Name + Local Name Local Name A hierarchical form: X/Y/Z e.g. trunk4/12/[email protected]; To identify DS0

number 7 within DS1 number 12 on DS3 number 4 at gateway.somenetwork.net Plain form: xxx e.g. 100@utag Wild-cards $, any; e.g., trunk1/5/[email protected]; CA wants to create a connection on an endpoint in a gateway and does not really care which endpoint is used. *, all; e.g., *@utag; MG uses this format to register.UTStarcom Confidential

MGCP key point--MGCP Commands (2) Call Agent Commands: EndpointConfiguration(EPCF) NotificationRequest(RQNT) CreateConnection(CRCX) ModifyConnection(MDCX) DeleteConnection(DLCX) AuditEndpoint(AUEP) AuditConnection(AUCX)

Gateway Commands: Notify(NTFY) DeleteConnection(DLCX) RestartInProgress(RSIP)

All commands are acknowledged.


MGCP key point--MGCP Packages (3)

Group events and signals into packages Generic Media (G) Gateway Supported packages DTMF (D) Trunk GW (ISUP) G, D, T, R MF (M) Trunk GW (MF) G, M, D, T, R Trunk (T) Network Access Server G, M, T, N Line (L) Combined NAS/VOIP GW G, M, D, T, N, R Access GW (VOIP) G, M, D, R Handset (H) Access GW (VOIP + NAS) G, M, D, N, R RTP (R) Residential GW G, D, L, R A, R Network Access Server (N) Announcement GW Announcement Server (A) The experimental packages have names beginning with the two character x-.


MGCP key point Registration (4) Use RSIP command Restart Method: -Forced -Restart -Disconnected -Graceful

-Cancel-graceful Three levels of register in the system - System level - Endpoint level

- Board level


Register (typical system register )

MGC

MG

(1) RSIP (*, RM:restart) (2) 200 OK

(3) AUEP (0, F:A) (4) 200 OK Reply with capability

(5) RQNT (*, R:L/hd) (6) 200 OK


Register (single endpoint register )

MGC

MG

(1) RSIP (249, RM:Forced)

(2) 200 OK (3) RSIP (249, RM:Restart)

(4) 200 OK


Register ( typical re-establish)

MGC

MG

(1) RSIP(*, RM:Disconnected) (2) 200 OK

(3) DLCX (*) (4) 250 OK

(5) RQNT (*, R:L/hd) (6) 200 OK


MGCP key point Heartbeat (5) Method to detect communication between MG and MGC Two types - MGC control heartbeat - MG control heartbeat - Two types are independent Implement on MG side - Create a timer when system first register done, timer length is configurable - In the interval of the timer, if there are messages between MG and MGC, do nothing but restart the timer - If no messages have been exchanged, MG sends the heartbeat message - If no response to the heartbeat after time out, MG will try to register again


Heartbeat messages

MGC

MG

MGC

MG

(1) NTFY (0)

(1) AUEP (mg)

(2) 200 OK

(2) 200 OK


MGCP key point-- Digit Map (6)

CA ask GW to collect user dialed digits - Created by CA Inter-digit Timer Usage - Gateways detect a set of digits. e.g., (11x|080xxxxxx|03xxxxxxx|002x.T) Request event:R:L/hu(N),D/[0-9#*ABCDT](D),L/oc(N) - Match accumulated digits under-qualified, do nothing further matched, send the collected digits to CA over-qualified, send the digits to CA


Basic call flow example--establishMG1Caller Off hook

MGC

MG2

(1) NTFY (O:hd)(2) RQNT (R:hu,hf) (3) RQNT (S:l/dl,R:hu,hf,D:digitMap)

Dial Num

(4) NTFY (O:dialed No.) (5) RQNT (R:hu,hf) (7) 200 OK (L:G729,p:20)

(8) CRCX (L:G729,p:20,m:inactive) (9) 200 OK (L:G729,p:20)

Ring back tone

(13) RQNT (R:hu,hf, S:rt)Stop tone

(12) RQNT (R:hd,S:rg,ci) (14) NTFY (O:hd) (16) RQNT (R:hu,hf)

Callee ring

Callee off hook

(15) RQNT (R:hu,hf, S:)

In conversation


Basic call flow example-- disconnect

MG1

MGC

MG2

In conversation

(1) NTFY (O:hu)Congestion tone

On hook

(3) DLCX (R:hu,hf, S:cg)On hook

(2) DLCX (R:hd)

(4) NTFY (O:hu) (5) RQNT (R:hd)


Basic call flow example-- Call waitingMG1 MGCMG1&MG2 already In conversation

MG3

(1) NTFY (O:hd) (2) RQNT

Off hook Dial tone

(S:dl,D:Digitmap)

(3) NTFY (O:Dialed MG1)

(4) CRCX (L:G729,p:20,m:rcvonly)Call waiting tone

(6) RQNT (S:L/wt,ci:MG3)

(5) 200 OK (L:G729,p:20,m:rcvonly) (7) MDCX (L:G729,p:20,m:rcvonly) (8) 200 OK (L:G729,p:20,m:rcvonly)

Flash hook

(9) NTFY (O:L/hf) (10) MDCX (L:G729,p:20,m:sndrcv) (12) 200 OK (L:G729,p:20,m:sndrcv)

(11) MDCX (L:G729,p:20,m:sndrcv) (13) 200 OK (L:G729,p:20,m:sndrcv)MG1&MG3 In conversation


Basic call example--Three way callMG1 MGCMG1&MG2 already In conversation Flash hook

MG2

MG3

Dial tone

MG3 numbers

(1) NTFY (O:hf) (2) RQNT (S:dl,R:Digitma p) (4) NTFY (O:MG3 numbers)

(3) MDCX (Announcement address) (5) CRCX (L:G729,p:20) (6) 200 OK (7) RQNT (S:L/rg,ci) (9) NTFY (O:hd) (10) MDCX (m:sndrcv,MG1 SDP )

MG2 hear announcement

Ring back

(8) RQNT (S:g/rt)

MG3 rings

MG3 off hook

(11) MDCX (m:sndrcv,MG3 SDP )Flash hookDial tone Press 3

MG1 & MG3 In conversation

(12) NTFY (O:hf) (14) RQNT (S:dl,R:Digitma p) (15) NTFY (O:3) (17) MDCX (Media server for bridge SDP)

(13) MDCX (Announcement address) (16) MDCX (Media server for bridge SDP) (18) MDCX (Media server for bridge SDP)

MG3 hear announcement

MG1 & MG2 & MG3 In conversation


Topics

Topics VOIP Introduction

MSAN VOIP Module Introduction Basic Voip Service Provision


VOIP module--SCM4

Functions of SCM4: Provide control function Provide whole node management Provide configuration functions Manages all POTS ports, DSP channels and the relevant timeslot resources Traces the status of each POTS port and DSP channel Connects with MGA (Media Gateway Application) for call control Communicates with VPM to for enhanced establishment of time slots and DSP channels


VOIP module-- VPM

VPM (Voice Processing Module), implementing the VoIP function.

Provide TDM-to-IP conversation 120 channel VPM capacity (with minimum RTP payload size of 20ms) A-Law to/from U-law conversion G.711,G.723, G.726, G.729AB voice coding Provide call progress tones Voice Activity Detection (VAD) Jitter buffer management Echo cancellation management DTMF tone detection or generation RFC 1889 RTP/RTCP


Relationship to Other SoftwareSCMIPBearer Module Media Gateway

VPMHardware Diagnostics VPM Media Task

Media Application Telogy Scaffold

RTEMS

Telogy DIM DSP Driver

Fast UDP Driver

DSP DSP

DSP DSP

DSP DSP


VOIP module-- IVD Provide ATM to IP conversation Supports 24 FXS ports, 24 ADSL ports, and 24 splitter ports Provides one or two Ethernet uplink interfaces IP-based ADSL, supporting ADSL2/ADSL2+. (IMA and ATM are optional). Providing an SNMP interface to SCM4 Supports FXS and enables V5 or VoIP-based applications Supports loop-testing (including POTS and ADSL) Controlled by the SCM4 (System Control Module of the iAN-8000). Hot swappable Fault management and alarm/event notifications


Function descriptionSCMIP SNMP UDL UDP IP UTMACEthern HDLCA et

IVD IVD Bridge UDL UDP IP UTMAC HDLC Ethernet Ethernet /IP Ethernet/IP 1483B AAL5 ATM ADSL

CPE IP Ethernet 1483B AAL5 ATM PHY

C Ethernet


Software module decomposition

IVDVoice Processing SNMP Proxy OAM

SCMIP

UDL Agent CM Init

Init UDP Socket Monitor CM

SNMP local Agent SNMP Proxy

TFTP Bridgin g RFC1483 IP Config Data IP Alarm

HIP ADSL Device Drivers Ethernet Device HDLC Device Diver Diver RTOS TimeSlot HDLC DeviceDriver TSI RTOS Ethernet


IVD Management

IVD

SCMIP

Voice Module

SBUS

Ethernet

MPC8260

Data Module

HDLC


Managed message flow EMS

100Mbps Ethernet

IVD MODULE

SCM3 MODULESNMP PROXY

CPE 1 CPE 2

SNMP AGENT

HDLC

IP ADSL

UDL MML

FXSPOLING TASK

CPE 24

SCB The CPE management information transfer path The ADSL part in IVD module management information transfer path The FXS part in IVD module management information transfer pathUTStarcom Confidential

Message exchange between IVD and SCM4IVD SCMIP

polling IVD status IVD respon se status IVD query versionn SCMIP response versio

IVD query cofig data

data SCMIP response cofig


Service FlowV5.2 SW or mSwitch TG

Internet

E1FE/GE Bus

VPM

ICM

TDM bus

ADSL2+

Splitter 4Khz, after split FXS

iAN-8000ADSL Modem


Topics

Topics VOIP Introduction MSAN VOIP module introduction

Basic Voip Service Provision


Provision in MSANDomain name


Provision in MSANcall server


Provision in MSANUser Class


Provision in MSANLogical ID


Provision in MSANvpm


Provision in MSANCountry Profile


Provision in MSANVoip Status&port number


Provision in MSANMGC authentication


Provision in MSANCodec profile


Thanks


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Voip Mgcp Ds