ISDN disconnection Cause Value=102

[Ralph John Tampilic]

Hi All,

We tried to have a test PSTN calls. First we dial 9293XXXX, the call is connected but when we tried to dial 9259XXXX we cannot hear anything in long seconds and it gives a fast busy tone.

Can you help me on this? I've searched what is Cause Value=102, and it means: recovery on timer expiry.

This is seen in situations where ACO (Alternate Call Offering) is being used. With this type of call pre-emption, the Telco switch operates a timer. For example, when an analog call is placed to a Netopia router that has two B Data Channels in place, the router relinquishes the second channel, but if it doesn't happen in the time allotted by the switch programming, the call will not ring through and will be discarded by the switch.

We don't know where is the problem, is it on Voice gateway or on Telco Side?

Thank you for your help

Regards,

RJ

[mkchandak · Accepted solution]

When you make an outbound call, after digits are are sent to Telco, the gateway waits for a call proceed or alerting message before ring is played to the phone, therefore you will hear since until this occurs. From the info available, if you can see the gateway send the setup to your telco and you get a disconnect from them, then it looks to be a Telco issue. You should collect debug Sidney q931 from the gateway and approach the Telco to understand why they send the disconnect. Looks like a routing issue on their end or an invalid number.

HTHs

Sent from Cisco Technical Support iPad App

[Jorge Armijo]

Hi,

Can you share with us the current configuration? Also, It would be better if you can capture the proper debugs while reproducing the issue, so we can take a look:

deb isdn q931

if MGCP controlled PRI: deb mgcp pack and deb mgcp back pack

if h323: deb voice ccapi inout, deb h225 asn1 and deb h245 asn1

Please share with us this outputs to help you on this matter. Please don't forget to specify the call and called number.

--

Jorge Armijo

[Ralph John Tampilic]

Thanks for the reply.

I already fixed the issue and we found out that this is the Telco issue.

Best regards,

RJ

[lightpath0323]

The telco is definitely sending the disconnect back in this case. 
I had this issue and it turned out that when I place the call the telco
side is expecting the calling number to be one of the DIDs that belongs
to me. simply because this was not the case, the call was not being processed
by the Telco. So Make sure the external phone number mask is one of the DIDs
that the telco knows and in the route pattern check the box that says:
Use external Phone number mask. (That solved my issue)