Outgoing Call Issue with Static SIP Trunk

[iTime]

Hello,

We have setup an IVR server for one of our customers, and it has a problem of calling out. (Call is sent from VG, but there is no response from SIP trunk.)

The SIP trunk has been configured to be simply "route calls to VG," so the VG config does not have "SIP Registration" as suggested from the previous thread (please see below link. you helped us setting it up.)

SIP Connection Failed with 500 "Internal Server Error" - General - VoiceGuide

With this, users can dial in to the VG Server, but the problem is that call out from VG to a destined number does not work.

Wireshark shows VG sends out the request but there is no response from SIP trunk.

We were told that it needs to send "9" as dial prefix, so the test calls in the log show this.

Please let us know what to try. The test call logs have 2 calls; one incoming and one outgoing call.

 

Thank you.

 

VGLog_CallOut_2021-08-04.zip

[SupportTeam]

WireShark trace shows the Cisco-CUCM12.0 device providing the SIP trunk to VoiceGuide is actually responding.

It is responding with a "100 Trying" and then with a "404 Not Found". And VoiceGuide then ends the call with a "DISCONNECTED" after it receives the "404 Not Found".

You will need to ask the administrator of the Cisco-CUCM12.0 device as to why it responded with a "404 Not Found" to the call attempt.

In the "404 Not Found" reply the Cisco-CUCM12.0 set the Q850 Cause Code to "1". ie: "Cause: Unallocated (unassigned) number (1)"

So looks like Cisco-CUCM12.0's did not know how to route that call...

 

[iTime]

Thanks for the quick response.

I have relayed the message to the customer's SIP Admin. We will see what he will come up to.

One more question regarding the outbound prefix.

The customer also mentioned their system needs "9" as prefix for outgoing call, so we are adding "9" to the testing phone number as you can see from above.

So my question is, would we also need to provide interval (i.e. After "9", wait for about 1 second then provide the phone number)?

If so, can that be done when feeding the number to VG?

[SupportTeam]

Quote

So my question is, would we also need to provide interval (i.e. After "9", wait for about 1 second then provide the phone number)?

No. That's not how it works on SIP calls. On SIP calls you just send one call initiation/request INVITE message.

[iTime]

41 minutes ago, SupportTeam said:

No. That's not how it works on SIP calls. On SIP calls you just send one call initiation/request INVITE message.

Does that mean,

adding "9" for the call INVITE (i.e. "91234567890@SIPAddress" --> 9 followed by phone number "123-456-7890") will work,

OR

SIP does not need a call prefix at all, thus "1234567890@SIPAddress"?

[SupportTeam]

What number format works depends on what the SIP device receiving the SIP INVITE message is set up to handle...

[iTime]

OK, it is clear now.

Thanks for the good details.