/mcp3640−6# 3640−6# 3640−6#configure terminal Enter configuration commands, one per line. End with CNTL/Z. 3640−6(config)#voice vad−time ? <250−65536> milliseconds 3640−6(config)#voice vad−time 750 3640−6(config)#end 3640−6# 3640−6# 3640−6# 3640−6#show run | be vad−time voice vad−time 750 Typical Configuration Examples for QoS A typical scenario for setting up VoIP calls is either over a frame−relay link or over a PPP link. These are configuration examples for these scenarios. VoIPoFR − QoS Configuration Example In this example (which contains only relevant sections of the configuration), it is assumed that the frame−relay circuit speed is 256 kbps. The guaranteed Committed Information Rate (CIR) on PVC 100 is 64 kbps and on PVC 200 is 192 kbps. PVC 100 is used to carry both data and voice. PVC 200 is used only to carry data. A maximum of four simultaneous voice calls exists at any given time. Configure fragmentation on both PVCs based on the CIR of the lowest−bandwidth−voice−PVC (PVC carrying voice). Based on the examples in this document, that means the fragmentation size is decided based on PVC 100's CIR (which is 64 kbps). As shown in the table of the Serialization Delay section, for a 64 kbps link, a fragmentation size of 80 bytes is required. The same fragmentation size needs to be configured for PVC 200. For further details about the configuration of VoIP over Frame Relay, refer to VoIP over Frame Relay with Quality of Service (Fragmentation, Traffic Shaping, LLQ / IP RTP Priority). 3660−1#show run Building configuration... ! class−map match−any voip match ip rtp 16384 16383 match ip dscp 26 46 class−map match−all voip−control match access−group 101 ! ! policy−map VoIPoFR class voip priority 48 class voip−control bandwidth 8 class class−default fair−queue ! voice call send−alert voice rtp send−recv ! ! interface Serial4/0:0 bandwidth 256 no ip address encapsulation frame−relay frame−relay traffic−shaping ! interface Serial4/0:0.1 point−to−point bandwidth 64