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Inter-switch MF Trunk Problems

We have an MF trunk between two Siemens EWSD switches. When this TG is connected to our VoIP routers, the router on the originating side will not process calls that have a 7 in the dial string.

It seems as though the router interprets the MF 7 as a DTMF 3 upon input and attempts to relay it to the other end. This results in a disconnect.

All other digits and call processing occurs normally if there is no 7 in the dial string.

The voice ports on both routers have been configured for wink start, inter-digit and digit delays to comply with the switch. The dial-type is set to MF. The dial peers are configured for a trunk connection and map ds0 to ds0.

In addition, we have verified that the orginating switch is sending a normal 7 in both frequency and duration. If we cross connect this trunk back to DS1 transport, everything works.

Not sure where else to go with this one as everyone is stumped... any direction is appreciated.


Re: Inter-switch MF Trunk Problems

Can you do the following:

Set router timestamps to the msec (in config mode) using the 'service timestamps debug date msec' command

turn off any other debugs (undebug all)

enable 'debug vpm signal'

Make a single test call and log the debugs

Post them here with the router SH RUN and the SH VER