/mcpfax interface-type ? modem Use modem card vfc Use Voice Feature Card
vnt-3660-23c(config)# fax interface-type vfc You must reload the router
Make sure you reload the router, or the command does not take effect. Fax calls fail on the platforms with Cisco fax relay (or T.38), so this is an important command to check. The fax interface-type vfc command was not necessary in Cisco IOS Software releases prior to 12.2. The problem is commonly seen when one of the voice gateways is upgraded to Cisco IOS Software Release 12.2 or later. 5. Make Sure that the Fax Codec is Loaded During the Fax Call Each fax machine displays the remote fax machine ID on its LCD screen at the completion of the fax negotiation phase. It is unlikely that the fax machines could complete negotiation if the fax codec had not been successfully downloaded. On the other hand, if no remote fax machine ID is displayed, further debugging in this area is appropriate. There are two ways to make sure that the voice gateways detect the fax transmission and successfully load the fax codec. Issue the debug vtsp all command and the debug voip ccapi inout call trace. These debugs are discussed in detail in the Debugging section of this document. 1. Issue the show voice trace command. Show commands are less resource intensive on the router than debug commands and are preferable in production networks. This is an example output from a show voice trace command on an ISDN interface. 2. show voice trace Command
<#root> BrisVG200gwy01# show voice trace 1/0:15 1/0:15 1 1/0:15 2 1/0:15 3 1/0:15 4 1/0:15 5 1/0:15 6 1/0:15 7 1/0:15 8 1/0:15 9 1/0:15 10 State Transitions: timestamp (state, event) -> ... 63513.792 (S_SETUP_REQUEST, E_TSP_PROCEEDING) -> 63515.264 (S_SETUP_REQ_PROC, E_TSP_ALERT) -> 63515.264 (S_SETUP_REQ_PROC, E_CC_BRIDGE) -> 63515.332 (S_SETUP_REQ_PROC, E_CC_CAPS_IND) -> 63515.332 (S_SETUP_REQ_PROC, E_CC_CAPS_ACK) ->