computer network audit

Stateful identification of computer network audit can differentiate and classify traffic on the basis of audio and video codec fields within the Real-Time Transport Protocol (RTP) payload of the packet. Although most voice classification is done in coarser granularity (by merely separating signaling traffic from speech path [media] traffic) and network access often is allowed or denied based on the originating port or IP address, sometimes traffic is desired to be classified by codec. One instance in which this is useful is at the trust boundary between an enterprise and a service provider network where the SLA is, for example, for G.729 and G.711 traffic only. In this instance, NBAR can be used to ensure that voice calls of other codecs are not allowed onto the network

The same mechanisms can be used if codecs of different bandwidth needs must be filtered out, for example, to ensure that call admission control (CAC) in the network is not broken. In this case, low-bandwidth codecs such as G.729 and G.723 can be separated from computer network audit traffic