ADTRAN AOS Version R10.1.0 Command Reference Manual page 1079

Command Reference Guide
ip rtp media-anchoring
Use the ip rtp media-anchoring command to enable media anchoring for all Real-time Transport Protocol
(RTP) calls. Use the no form of this command to return to the default setting.
ip rtp media-anchoring
ip rtp media-anchoring session timeout <value>
Syntax Description
session timeout <value>
Default Values
By default, media anchoring is disabled. If media anchoring is enabled, the default session timeout value
is 45 seconds.
Command History
Release R10.1.0
Usage Examples
The following example sets the media anchoring session timeout period at 60 seconds:
(config)#ip rtp media-anchoring session timeout 60
Technology Review
Media anchoring, through the use of Session Description Protocol (SDP) manipulation, directs all RTP
packets generated in the local network to the media anchoring device (an AOS unit with media anchoring
enabled). Outgoing RTP packets, which contain the source IP address and port number of an Internet
Protocol (IP) private branch exchange (PBX) or phone, and the destination IP address and port of the
media anchoring device, are modified to be sourced from the gateway and destined to the public network.
The process is reversed for incoming RTP packets.
When a local Voice over Internet Protocol (VoIP) phone makes a call to the public network, the local
network will be configured to have all SIP messages routed to the media anchoring device. The media
anchoring device will receive a Session Initiation Protocol (SIP) packet with an SDP offer from the IP
phone when it tries to make the call.
If media anchoring is enabled, the media anchoring device will, based on the SDP offer, determine the
egress interface for relaying the SDP to the public network and substitute the IP address of that interface
for the connection information IP address contained in the original SDP offer. Additionally, it will substitute
a port number in the media anchoring range (User Datagram Protocol (UDP) 10000 and above) in any
media descriptions. The offer will then be relayed on the appropriate outbound SIP trunk. This will cause
RTP from the public endpoint to be routed to the media anchoring device instead of the VoIP phone.
60000CRG0-35E
Specifies the timeout period, in seconds, of an anchoring association after
the associated RTP packet flow ends. Range is 32 to 900 seconds.
Command was introduced.
Copyright © 2012 ADTRAN, Inc.
Global Configuration Mode Command Set
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