Configure Voice over IP using a Trunk Connection
The routers on both sides of the Voice over IP connection must be configured for trunk connections. For the scenario described in Figure 11, configure Router A to support trunk connections as follows:
configure terminal
connection trunk +15105554000
For the scenario described in Figure 11, configure Router B to support trunk connections as follows:
configure terminal
connection trunk +13085551000
To configure virtual trunk connections in Voice over IP, use the connection trunk command. The following conditions must be met for Voice over IP to support virtual trunk connections:
•Use the following voice port combinations:
—E&M to E&M (same type)
—FXS to FXO
—FXS to FXS (with no signaling)
•Do not perform number expansion on the destination pattern telephone numbers configured for trunk connection.
•Configure both end routers for trunk connections.
•The connected Cisco routers must be Cisco 2600 or Cisco 3600 series routers. The Cisco AS5300 does not currently support trunk connections.
Note Because virtual trunk connections do not support number expansion, the destination patterns on each side of the trunk connection must match exactly.
VoIP establishes the trunk connection immediately after it is configured. Both ports on either end of the connection are dedicated until you disable trunking for that connection. If for some reason the link between the two switching systems goes down, the virtual trunk