int-calls low 5 high 2500 call treatment cause - code no - resource call treatment on The call threshold global total-calls command controls the total number of calls to be supported on the CUBE. The command tracks the number of calls, rejecting the 25th call and not accepting calls again until the total number of calls falls below 20. The cpu-avg and total-mem options rejects the calls if the CPU or memory of the border element exceed the given thresholds regardless of the actual active call count. The call threshold interface command limits the number of calls over a specific IP interface. The call treatment cause-code no-resource command correlates (by default) to a SIP 503 Service Unavailable message sent when calls are rejected. Quality of Service (QoS) Cisco provides many methods of measuring and ensuring QoS in an enterprise IP net- work. You should always use these methods internally when designing a UC system, and you should also extend them to the interconnect point when using a SIP trunk to connect to a service provider. Consider several areas of QoS including: Traffic marking Delay and jitter Congestion management Traffic Marking QoS on IP networks depends on the QoS marking on the IP packets. As with codec set- tings, QoS markings on voice signaling and media IP packets on IP call traffic inbound from the PSTN on a TDM gateway is easily predicted and controlled by the configura- tion on your gateway. On SIP trunks, the default packet markings are whatever the serv- ice provider sets them to and this might not be in line with your enterprise policies. 128 SIP Trunking The CUBE can re-mark all media and signaling packets that enter you network or exit your network to comply with the SP UNI specification. Re-marking can be done on a per-dial-peer basis (that is, per voice call destination) or per interface (either ingress or egress or both). Example 7-9 shows how to mark packets per dial-peer. Example 7-9 Marking QoS on a Dial-Peer ial-peer voice 40800011 voip destination-patter 408 session protocol sip