Configure Voice Service Voip Sip Bind - Avaya 2330 Reference Manual

When negotiating a SIP session, each SIP peer generates a Session Decription Protocol (SDP)
offer/answer message that specifies the media streams and codecs it wishes to use, as well
as the desired IP addresses and ports to use to receive the media.
When the session is established and the AG2330 receives the RTP stream from the peer, by
default, the AG2330always verifies that the port from which the stream is sent matches the
advertised port in the SDP offer/answer. This provides an additional layer of protection for the
VoIP calls.
However, the SDP offer/answer message specifies only the receiving port, not the sending
port. While peers typically send and receive the RTP stream on the same port, they are not
required to do so. As a result, if the peer sends the RTP stream from a port that is different
from the advertised receiving port, the AG2330 interprets this as an RTP source port mismatch
and does not forward the media to the connected TDM ports. This results in no speech path
for the TDM ports.
To identify whether RTP port validation is the source of a speech path issue, you can perform
a packet capture and analyze whether the peer is sending and receiving the RTP stream from
the same port.
If the packet capture shows different sending and receiving RTP source ports, disable RTP
source validation.
Syntax
[no] rtp port-validation
Table 341: Variable definitions
no rtp port-validation
rtp port-validation
Example
AG/configure/voice/service/voip# no rtp port-validation

configure voice service voip sip bind

Use this command to bind the source address for SIP signaling and media packets to the IP
address of a specific interface. This instructs the interface to listen for SIP signaling and media
packets.
You must configure at least one interface to listen for SIP signaling and media traffic, otherwise
the Media Gateway cannot recognize incoming SIP traffic and is isolated from the VoIP
network. You can configure either one interface to receive both signaling and media traffic, or
one interface to receive the signaling traffic and a second interface to receive the media traffic.
This allows load-sharing of the SIP traffic.
Command Line Reference
Variable
configure voice service voip sip bind
Value
Disables the RTP source port validation of
the peer.
Enables the RTP source port validation of the
peer.
August 2013 317