Specifications

Chapter 4 - MGCP Protocol Features Interoperability Configuration

Mediatrix 4100

The following values are available:

Offered Stream Format

RFC 3264 stipulates that to reject an offered stream, the port number in the corresponding stream in the

answer must be set to zero. However, some gateways prefer to remove the unwanted stream from the answer.

The answer to an offered session description is based on the offered session description.

 To define the stream format:

1. In the mgcpncsExperimentalMIB, set the mgcpncsAnswerStreamFormat variable to the proper

value.

Session ID and Session Version

You can define the maximum length of the session ID and session version number in the origin line (o=) of the

SDP.

 To define the session ID and session number:

1. In the mgcpncsExperimentalMIB, set the mgcpncsOriginLineSessionIDAndVersionMaxLength

variable to the proper value.

Table 57: Offer/Answer Model Parameters

Parameter Description

disable The peer can freely:

• Send back a brand new list of codecs or add new ones to the offered

list.

• Add media lines AFTER the ones found in the offer.

As long as at least one codec sent back is supported by the Mediatrix 4100,

the call is allowed to go on. Any media lines added by the peer is simply

ignored.

enable The following guidelines from the Offer-Answer Model must be strictly

followed. An answer must:

• Include at least one codec from the list that the Mediatrix 4100 sent

in the offer.

• Avoid adding extra codecs that were not present in the offer.

• Contain the same number of media lines that the unit put in its offer.

Otherwise, the answer is rejected and the unit ends the call. This is the default

value.

Table 58: Offered Stream Format Parameters

Parameter Description

zeroAnswerStream The port number is set to zero if the corresponding stream in the answer

is unwanted. This behaviour follows the RFC 3264 best practice. This is

the default value.

removeAnswerStream The unwanted stream is removed from the answer and returned to the

offerer. This behaviour is kept for backward compatibility issue.

Table 59: Session ID/Version Parameters

Parameter Description

none The session ID and the session version number are represented by the

0 value. This is the default value.