Outbound SIP calls to invalid numbers

[Ronald Smith]

what is the expected behavior for a sip call to an invalid number? and what would cause it to behave differently?

[Mohammed Khan]

Hi Ronald, 

If i understand your question correctly you want to know the behavior of call when invalid number is dialed.  When you place a call to invalid number. Telco or far end should Respond to SIP Invite with SIP 404 Not found in such case CUCM invokes Annunciator to play a messages.

HTH,

Regards,

Mohammed Noor

[Ronald Smith]

Mohammed, thank you for the quick response.

The problem is  outbound calls to invalid numbers are ringing then timed out. As you stated , the expected behavior is “Telco or far end should Respond to SIP Invite with SIP 404 Not found in such case CUCM invokes Annunciator to play a messages.”, but it’s not happening.

[Mohammed Khan]

Hi Ronald,

Whats the call flow ex IP Phone --SCCP-> CUCM --SIP --> CUBE -SIP-> Telco

If called number is invalid then call should not ring. Why is  far end responding back with ringing.

Can you grab below debugs from the VG

++ debug voice ccapi inout

++ debug ccsip messages

HTH,

Regards,

Mohammed Noor

[Suresh Subramanian · Accepted solution]

Hi Ronand, if your CUCM is 8.X or above, Pls enable Early Offer in the SIP Profile applied to the SIP Trunk and check. you can also enable PRACK in the same profile or in the CUBE if it is in your call flow.

[Ronald Smith]

Thank you everyone, enabling PRACK in the SIP profile associating with SIP trunk did fix the problem.