Cisco TelePresence Video Communication Server (VCS)

VCS not responding to an H.323 RAS bandwidth request from a neighbor

Why does the Cisco TelePresence Video Communication Server (Cisco VCS) not respond to an H.323 RAS Bandwidth Request (BRQ) message from a neighbor?

H.323 BRQs inform gatekeepers of the bandwidth that is being used by an endpoint for a call. BRQs should only be sent from an endpoint to the gatekeeper to which it is registered (the BRQ includes an endpoint ID that is assigned to the endpoint by the gatekeeper registration process). BRQs are not used to share bandwidth information between two neighbors.

If you do have a system that is neighbored to the Cisco VCS and want it to be able to provide bandwidth information to the Cisco VCS, this can be achieved in the following ways:

  • (optionally) in LRQ messages (bandwidth 10240 = 1Mbps)
  • included in SETUP messages as the Information transfer rate: in the Bearer Capability. The rate represents a multiplier of 64kbps, so for example a rate of 136 will equal a bandwidth of 8704kbps (136*64kbps = 8704kbps)
  • included in the terminalCapabilitySet capability table and capability items as maxBitRate. NB: a maxBitRate of 5120 = 512kbps

This article applies to the following products:

  • Cisco Video Communication Server

June 16th, 2011TAA_KB_184