Dialing out to a certain number won't ring while call is connecting

[hartgravesc1]

Hello, we have discovered a couple numbers that do not ring while the call is connecting from a Cisco VoIP endpoint. The two numbers are 610-328-1500, and 517-827-0273. When we try to call the number, it says "Connecting...", and then after approximately 15 seconds, we get a fast busy signal for about 3 seconds, then it rings once, and the party on the other side picks up.

The call path goes like this: Cisco 7965>SIP>CUCM 10.5>2911 Gateway>T1 to NEC PBX>Fiber PRI>PSTN

The two number can both be reached fine via one of our NEC PBX phones, as well as a cell phone. I can also call numbers that are very similar, such as 610-328-1234, as opposed to 610-328-1500.

This is the first time I've run into this issue. Any thoughts?

[Ronak Agarwal]

Hi,

Are you getting a fast busy, instead of a ringback and it rings once? What happens if you do not answer the call from 610-328-1500 or 517-827-0273?

Is this issue with all the calls to both the numbers from a cisco phone?

Was this working before?

When you say T1, is it MGCP or H.323 gateway?

We may have to look at call manager traces to determine the cause?

Can you also share the output of DNA from servicability?

Regards,

Ronak Agarwal

[hartgravesc1]

Hi Ronak,

-The issue when making the call to one of these numbers, we get about 20 seconds of silence, then fast busy for about 3 seconds, then it rings once, and then the party picks up or we get voicemail. I do not know what happens if the other party were to call us.

-The issue occurs with both numbers from a Cisco 7965 and a 9971.

-I do not know if it was working or not before. However I can say that I personally have never ran into this problem, and this is the first time I am receiving a trouble ticket about it. 

-The gateway is MGCP I believe

-Attached is the DNA output for calling the 610 number from my desk phone. 

Thank you for responding.

[Ronak Agarwal]

As per the DNA output, it seems to be a SIP trunk and the call is using Route Pattern :Pattern= 9.1[2-9]XX[2-9]XXXXXX

 Device :Type= SIPTrunk
                    End Device Name = SC09-2911
                    PortNumber = 0
                    Device Status = UnKnown
                    AAR Group Name =
                    AAR Calling Search Space =
                    AAR Prefix Digits =
                    Call Classification = Use System Default
                    Calling Party Selection = Originator
                    CallingLineId Presentation = Default
                    CallerID DN =

Is this correct call flow? Can you compare this with the working one?

Regards,

Ronak Agarwal

[hartgravesc1]

Ronak, attached is a DNA output where I called a local cell phone and received ringing.

[Ronak Agarwal]

As per the DNA output, it seems to be using the SIP trunk on device SC09-2911. Working and Non-working using the same router.

Please login to the router and collect the output of below debugs:

1) debug ccsip messages

2) debug voip ccapi inout

Ronak Agarwal