Avaya 555-245-600 Manuale Utente

CB-WFQ/LLQ is a priority-aware queuing strategy that has a strict priority queue for voice 
packets, and does round-robin queuing for other types of traffic. Non-prioritized traffic is still 
forwarded, however, so this should not interfere with a customer’s data network. Use weighted 
random early detect to manage the fair queue.
The actual router configuration used for this testing follows. First, set the endpoints to tag 
interesting traffic as DSCP 46. Cisco routers support DiffServ in IOS 12.0 and later. Next, set up 
a class map to match traffic that is marked with DSCP 46. Once traffic is defined by the class 
map, set policies for it using a policy map. For the policy map to take effect, it has to be applied 
to an interface. Queue packets on the outgoing interface. In the sample configuration, 768 K of 
bandwidth is reserved for RTP. This value should be set at or above the maximum bandwidth to 
be used for IP Telephony. In our case, 768 K supports 9 calls using G.711, or 31 calls using 
G.729. This example should work well in most cases using Cisco routers with point-to-point 
WAN links. Networks that use Frame Relay might need additional steps.

Suppose all endpoints are capable of tagging with DSCP 46, which is the default for audio. This 
would be true in a Communication Manager system with TN799DP C-LAN circuit packs running 
firmware v5 or later. Previous firmware versions and the TN799C circuit pack cannot tag at 
Layer 2 or Layer 3. A matching set of configurations is applied to both routers.