Cisco Systems SPA9000 IP Phone User Manual


 
Advanced Topics in SPA9000 Administration
Technology Background
SPA9000 Voice System Administration Guide 168
A
To enable the media proxy, go to the Voice > SIP page, PBX Parameters section,
and set the Force Media Proxy parameter to True. With the media proxy enabled,
when UserA calls User C, the SPA9000 still acts as the SIP proxy and forwards the
request to the SIP server on the ITSP. However, even after the SIP session is
established, the SPA9000 continues to direct RTP packets between UserA and
the ITSP.
Local traffic is not affected by this configuration. When UserA initiates a call to
UserB, RTP traffic still flows directly between the two UAs. The media proxy only
affects RTP traffic to a UA connected through the ITSP.
Using the SPA9000 with a Firewall or Router
When using the SPA9000 behind a firewall or router, make sure that the following
ports are not blocked:
SIP ports—By default, UDP ports 5060 through 5063
RTP ports—16384 to 16482
Also disable SPI if this function exists on your firewall.