TTYredirector Knowledge Base

Cisco routers with digital modems require that an "X" character be placed in front of any DTMF data (dual tone multi-frequency) that is sent in a dial string after a phone number.  For more information see:

 

If you needed to dial the phone number 1234567890, pause for 15 seconds and then dial 12345, the dial string would need to be sent to the modems as 1234567890X,,,,,12345

If you find that this solution doesn't work with an application that you need to use, We suggest that you contact Cisco.  They made a patch in the IOS for certain routers that will allow control over what character is used to signal the start of DTMF signals.  Then you can choose a character will always pass (such as @).  If you do need to contact Cisco about this, you should refer to case SR 600482576.