Strange Mobile phone Issue

Unanswered Question
Jul 8th, 2010


Wondering if anyone has experienced something similar to this issue.

When calling a specific DID extension from the PSTN through a H323 gateway from a landline the call is successful........but when dialing from a mobile (tried serveral providers) the call gets a busy tone. When dialing any other DID extension through the same gateway from a mobile it is successful.

On debuging the gateway (debug isdn q931) we cannot see the call hitting when calling from a mobile at all - when calling from a landline the dubug show the call coming in as expected. When dialing any other extension from a mobile the debug shows call coming in as expected

The telco has pushed it onto us saying it is a local gateway problem as they are getting unallocated number error on their side.........but the call is not even getting to the gateway so how can it be???

Is there any other way to get proof it is the telco's problem?


I have this problem too.
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David Hailey Thu, 07/08/2010 - 06:48

I've seen variants of these types of issues in the past.  One key thing is to test from multiple mobile carriers.  In my experience, the call routing for one carrier is off but others will typically work fine.  Once you do that, you can escalate the issue with the carrier and provide for them all of the traces and debugs that show A, B, and C work fine but their service, D, is hosed up.  I can't say that I was very polite in ultimately getting resolution on these types of things as carrier's typically point the finger to you and then make it painful to follow-up.  So, you may have to break out some "tough love" once you have all your ducks in a row.


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rchaseling Thu, 07/08/2010 - 07:15

Cheers David - to me from the tests we have done it HAS to be a telco issue but as you know you have to usually hit them them with irrefutible proof. Thanks for the reply

David Hailey Thu, 07/08/2010 - 07:34

Based on your info, I would agree that it appears to be a Telco issue.  If the call is never hitting your gateway then it's being misrouted or lost before it ever gets to you.  In the past, I dealt with a similar issue where one particular carrier (mobile) had an incorrect routing entry for 3-4 numbers and any calls to those numbers were lost within their cloud.  Other carriers worked fine and local land lines worked fine.  It took me a few days and probably a few blood pressure increases as well, but ultimately the issue was almost "magically" resolved with no admittance of error.



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