CUCM SIP Dial Rules: Handling DTMF for TypeSIP Phones

Receiving DTMF for TypeSIP Phones on CUCM

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A CUCM engineer has deployed TypeSIP Phones on a remote site and no SIP dial rules were deployed for these phones.

How will CUCM receive the DTMF after the phone goes off- hook and the buttons are pressed?



Click on the arrows to vote for the correct answer

A. B. C. D.


When a TypeSIP phone is taken off-hook and a digit is dialed, the phone sends a SIP INVITE message containing the dialed digit to the CUCM. The CUCM uses the dialed digit to match against the configured dial plan and determine the appropriate route pattern.

In this scenario, since no SIP dial rules were deployed for the TypeSIP phones, the CUCM will receive each digit in a SIP INVITE message as soon as it is dialed. Therefore, options C and D are possible answers.

Option A is incorrect as NOTIFY messages are used for events or changes in a call, such as call transfer or call hold, rather than for dialing digits.

Option B is also incorrect as subsequent digits would be sent in subsequent SIP INVITE messages rather than NOTIFY messages.

Therefore, the most accurate answer to this question is option D: all digits will be received by CUCM in a SIP INVITE as soon as the dial softkey has been pressed.