Packetizer

Bandwidth is Bi-directional (Q10)


The information in this article applies to: H.323, H.225.0

The RAS bandwidth field refers to bandwidth usage in both directions, not just in the out-going direction, as is often believed. 7.11.1/H.225.0v2: "bandWidth - the number of 100 bps requested for the bi-directional call. For example, a 128 Kbit/sec call would be signaled as a request for 256 Kbit/sec. The value refers only to the audio and video bit rate excluding headers and overhead."

An end station should make an estimate of the total transmit and receive bandwidth for audio and video based on what it wants to send and what it knows it can receive based on the capabilities it plans to advertise. It should place this estimate in the bandwidth field of the ARQ. If the resultant aggregate bandwidth of the call is less than the amount it was pre-granted, it can release the difference with a BRQ.