Cisco Systems 3600 manual Configure Voice over IP using a Trunk Connection

Configure Voice over IP using a Trunk Connection

Configure VAD for a VoIP Dial Peer

To disable the transmission of silence packets for a selected VoIP peer, use the following commands beginning in global configuration mode:

The default for the vad command is enabled; normally the default configuration for this command is the most desirable. If you are operating on a high bandwidth network and voice quality is of the highest importance, you should disable vad. Using this value will result in better voice quality, but it will also require higher bandwidth requirements for voice.

For example, to enable VAD for VoIP dial peer 108, enter the following:

dial-peer voice 108 voip destination-pattern +14085551234 vad

session target ipv4:10.0.0.8

Configure Voice over IP using a Trunk Connection

A trunk is a communication line between two switching systems; typically, the switching equipment in a central office and a PBX. A trunk connection is a permanent physical layer (wire), point-to-point connection.

Voice over IP simulates a trunk connection by creating virtual trunk tie lines between PBXs connected to Cisco 2600 and 3600 series routers on each side of a VoIP connection. (See Figure 11.) In this example, two PBXs are connected using a virtual trunk. PBX-A is connected to Router A via an E&M voice port; PBX-B is connected to Router B via an E&M voice port. The Cisco routers spoof the connected PBXs into believing that a permanent trunk tie line exists between them.

Figure 11 Virtual Trunk Connection

Configuring Voice over IP for the Cisco 3600 Series VC-35