Registration problems with Polycom endpoints and the Cisco TelePresence Video Communication Server (Cisco VCS)
Polycom HDX9004 endpoints
A Polycom HDX9004 endpoint will keep losing its registration with the Cisco VCS because the Polycom endpoint does not refresh its registration within the default period required by the Cisco VCS. You cannot change this setting on the Polycom endpoint, therefore in order to fix this problem you must change the setting on the Cisco VCS, so that it requires SIP registrations to be refreshed within the same time period used by the Polycom endpoint.
The standard SIP registration process is as follows:
- A SIP endpoint sends a registration request to the SIP registrar (in this case a Cisco VCS).
- The Cisco VCS accepts the registration and advises the endpoint of the frequency with which the endpoint must refresh its registration in order to remain registered (this frequency is determined on the Cisco VCS by the SIP Registration expire delta setting).
- The SIP endpoint sends a registration refresh request to the Cisco VCS. If the Cisco VCS does not receive this request within the frequency specified, it will remove the registration.
The default frequency on the Cisco VCS is 60 seconds; the default frequency on the Polycom HDX9004 is 300 seconds.
Normally endpoints will adjust the frequency with which they send the registration refresh requests according to the Registration expire delta information received from the SIP registrar. However, the Polycom HDX9004 does not respond to this information and continues to send the registration refresh messages every 300 seconds. This frequency is not configurable on the Polycom endpoint. If the Registration expire delta setting on the Cisco VCS requires that the refresh messages are sent more frequently than 300 seconds (which it does by default), the Cisco VCS will consider the registration to have expired after the period specified by the Registration expire delta setting. When the Polycom HDX9004 sends its next registration refresh message, the Cisco VCS considers this to be a new registration request, and so re-registers the endpoint (but only for the period specified by the its Registration expire delta setting).
The work-around for this is to change the Registration expire delta setting on the Cisco VCS (VCS configuration > Protocols> SIP > Configuration) to be greater than 300 seconds.
Note: changing the
Registration expire delta setting on the Cisco VCS will affect the frequency with which all SIP endpoints must re-register, not just the Polycom HDX9004. If you have Presence enabled on the Cisco VCS, it will also affect the frequency with which the PUA updates the presence status of SIP endpoints.
Registering a Polycom VSX7000 to a Cisco VCS Expressway or a Cisco acquired TANDBERG Border Controller
Polycom does not support multiplexed media as described in H.460.19 standard - it only supports H.460.18. To register a Polycom VSX7000 to a Cisco VCS Expressway or a Border Controller, you must disable H.460.19 demultiplexing on the target system.
To disable this setting on a Cisco VCS Expressway, go to VCS configuration > Expressway > Locally registered endpoints and set H.460.19 demultiplexing mode to Off.
To disable this setting on a Border Controller, go to Border Controller Configuration > TraversalZones and set H46019 Demultiplexing to Off.
This article applies to the following products:
- Cisco Video Communication Server
| June 16th, 2011 | TAA_KB_435 |