0AA000004 Bear Control Protocol MGCP ISSUE2.0

7/30/2019 0AA000004 Bear Control Protocol MGCP ISSUE2.0

1/30

ISSUE

Fixed Network Curriculum

Development Section

2.0

OAA000004 Bearer controlprotocol MGCP protocol


2/30

Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal

2

Objective

MGCP functions

MGCP commands

Meanings and usage of the

parameters in MGCP commands

MGCP message interaction process

After this session, you will learn:


3/30


3

References

Product Manual -- Technical Manual -- Signaling and

Protocols -- MGCP


4/30


4

About this session

Section 1 Overview

Section 2 Message Structure

Section 3 Call Flow


5/30


5

Bearer Control Protocols

Bearer control protocols are used for the communication

between a Media Gateway Controller (MGC) and a Media

Gateway (MG).

As control-layer equipment, SoftX3000 supports two bearercontrol protocols:

MGCP and H.248.

MGC MG

IP DATA


6/30


6

Concept

MGCP : Media Gateway Control Protocol

assumes a call control structure in which the call control

functions are gateway-independent and are processed by the

external call control unit.

a master/slave protocol. The gateway needs to execute the

commands sent from the MG controller.


7/30


7

Terms

Gateway

Gateway : a network element that provides interconnection and inter-

working between networks of various architectures. In NGN architecture,

NGN inter-works with other networks via certain gateways.

Trunk Media Gateways (TMG): It provides the interfaces between the

traditional telephone network (PSTN) and a Voice over IP (VoIP)

network.

Access Media Gateways (AMG): It provides a traditional analog

subscriber line interface or a digital PBX interface to a Voice over IP

network.

Residential Gateways (RG): It is an entity that provides traditional

analog (RJ11) interfaces to VoIP network. Examples of residential

gateways include cable modem/cable set-top boxes, xDSL devices, and

broadband wireless devices


8/30


8

Terms

Call Agent :

handles the signaling and call processing functions, and it is

external call control element controlling Telephony Gateways.

SoftX3000 system provides MGCP call agent functions. SoftX3000

can act as the access point for MGCP E-phones and softphones in

the network.

End point:

It refers to the originating end or receiving end of data. It can be a

physical concept or a virtual concept.

Media Resource Server (MRS):

It is a type of gateway that supports endpoint types such as

announcement server access point, interactive voice response

access point, conference bridge access point, etc.


9/30


9

Terms

Terminal nameincludes

Domain name of the gateway

Interface name of the terminal in gateway

@is use to seperate domain name and interface name, theform is like Email address

Examples:

AGaaln/1 @ amg1.hauwei.comrefers to the first interface

named aaln in AG named amg1.hauwei.com

TGX35V3+A4/[email protected] refers to the 13th

TDM circuit on interface X35V3+A4 which is in

gw23.example.net


10/30


10

Terms

Call connection:


11/30


11

MGCP Implementation in SoftX3000

PSTN

SoftPhone

TMG8010

MRS

IAD

E-phone E-phone

IP Core

SS7

E1


12/30


12

Inter-working Support

SoftX3000 supports interworking between MGCP and the following protocols:

SIP: SIP User and SIP trunk;

H.323: H.323 User and H.323 Trunk

ISUP: PSTN user through ISUP trunk

SIP

PSTN

IP Core

H.323

SIP Terminal

H.323 Terminal

SIP

H.323

ISUP

IAD

MGCP


13/30


13

Protocol Stack

MAC

MGCP

IPUDP

SM (ISUP/TUP/SIP/H.323/ESL)


14/30


14

About this session

Section 1 Overview


Section 3 Call Flow


15/30


15

Message Types:

MGCP messages exchanged between MGC and MG have 9

types

they are called commands when being sent to MG or MGC,

while called responses when being returned from MG orMGC.

Command and response are inseparable. Upon receiving a

command, MG (or MGC) will return a response immediately.


16/30


16

Command Line

A command line is composed of

the name of the requested verb (command name)

the identification of the transaction,

the name of the endpoint (entity)

the protocol version. These four items are separated by spaces.

Command

name

Identification

of transaction

End point

Parameter: Parameter value:

Parameter: Parameter value:

...

Protocol versionCommand

line

Parameter

line


17/30


17

Command Name

Item Command Name Code Description

1Endpoint

ConfigurationEPCF

MGCMG, used to inform the gateway about the

coding characteristics expected by the "line-side" of

the endpoint.

2 CreateConnection CRCX

MGCMG, used by call agent to associate an end

point with a specified IP address and UDP port.

Apart from that, a CreateConnection command is

also sent to the remote endpoint to create the

connection between the two endpoints.

3 ModifyConnection MDCXMGCMG, used to change the parameters of a

previously established connection.


18/30


18

Command Name

Item Command Name Code Description

4 DeleteConnection DLCXMGCMG, used to delete a

previously established connection.

5 NotificationRequest RQNT

Used to instruct the gateway to

watch for specific events on a

specified endpoint. If it happens, the

Call Agent will be notified.

6 Notify NTFY

MGMGC, used by the gateway to

notify the Call Agent that a specific

event requested to watch for takes

place


19/30


19

Command Name

Item. Command Name Code Description

7 AuditEndpoints AUEP

MGCMG, used by the Call Agent to

obtain the detailed information of an

end point or a group of endpoints

8 AuditConnection AUCX

MGCMG, used by the Call Agent to

obtain the detailed information of a

connection on an end point

9 RestartInProgress RSIP

MGMGC, used by the gateway to

notify the Call Agent that an end point

is getting out of or into service


20/30


20

Command Example

RQNT 4561 [email protected] MGCP 1.0

N: [email protected]: 5777

X: 45848484

R: hd


21/30


21

Command Response Format

The response line consists of :

the response code

Values between 200 and 299 indicate a successful completion.

Values between 400 and 499 indicate a transient error.

Values between 500 and 599 indicate a permanent error.

transaction identifier

an optional commentary, which are separated by white spaces.


22/30


22

Command Response Example

200 1203 OK

C: A3C47F21456789F0

N: [128.96.41.12]

L: p: 10, a: PCMU; G726-32

M: sendrecv

P: PS=1245, OS=62345, PR=780, OR=45123, PL=10,

JI=27,LA=48

v=0


23/30


23

Command Response Example (Cont.)

c=IN IP4 128.96.41.1

m=audio 1296 RTP/AVP 0

v=0

c=IN IP4 128.96.63.25

m=audio 1296 RTP/AVP 0 96

a=rtpmap:96 G726-32/8000


24/30


24

About this session

Section 1 Overview


Section 3 Call Flow


25/30


25

Scenario 1MG Registration

SoftX3000MG

RSIP

RSIP_RSP


26/30


26

Scenario 2 - Successful Call

User MG SoftX3000 MG User

1 RQNT

ACK

2 NTFY

ACK

3 RQNT

ACK

4 NTFY

ACK

5 CRCX

ACK

8 RQNT

Off-hook

ACK

Dail tone

Ringbacktone

6 CRCX

ACK

Ringing

Off-hook9 NTFY

ACK

Dailing

7 RQNT

ACK


27/30


27

Scenario 2 - Successful Call (continued)


11 MDCXACK

16 NTFY

ACK

13 DLCX

ACKBusy tone

14 DLCX

ACK

On-hook12 NTFY

ACK

On-hook

10 MDCX

ACK

CONVERSATION

15 RQNT

ACK

17 RQNT

ACK

13 MDCX

ACK


28/30


28

Scenario 3 - Unsuccessful Call Flow


1 RQNT

ACK

2 NTFY

ACK

3 RQNT

ACK

4 NTFY

ACK

5 RQNT

ACK

Off-hook

Dail tone

Dailing

Busy tone

On-hook 6 NTFY

ACK

7 RQNT

ACK


29/30


29

Summary

Concept and function of MGCP: The MGCP protocol is used

for communication between MGC and MG. It is a bearer

control protocol.

MGCP includes 9 commands and 3 types of responses. Eachcommand consists of 4 parts; values 200~299 indicate

success, and the other values indicate failure.

The role of each command in MGCP call flow must be

mastered as the key point.


30/30

Confidential Information of Huawei.

30

0AA000004 Bear Control Protocol MGCP ISSUE2.0

Documents

Transcript of 0AA000004 Bear Control Protocol MGCP ISSUE2.0