Handsets are displaying full country code prefix but only on one incoming DDI number 5

[outonalimb]

Hi,

We have a weird issue with incoming calls on just one of our DDI numbers in that it's placing the full country prefix (0044) on most calls on the user handset. This means no directory matching is taking place. All DDI's are supplied by one SIP trunk provider and they say that it's nothing they are doing at their end.

We've changed the incoming call route to another bunch of extensions and the problem follows so we've ruled out the phones, etc. No other incoming calls on other numbers are being affected.

Does anyone have any ideas?

Cheers

 

[snowman50]

First thing is to check all parameters are the same for this trunk compared to a working trunk.

Use SSA to see if there is any difference in the incoming call compared to a working one.

 

[outonalimb]

All calls come in on the one trunk. See image for an example. Top line is a working number, no issues. Bottom line shows the offending number with the 0044 being prefixed. SIP provider say it's nothing at their end!

 

[IPid10t]

If you go to the original user having the issue and go to their SIP tab how is that programmed?Try placing their DID in the "SIP Name" and the "Contact" field. I have seen that this can cause inbound issues weird enough.

 

[Ekster]

Check if the calls with 0044 are coming through the Auto attendant and calls with correct number are not.

If so, you can fix it by setting "Caller ID from FROM header" to "ON" in the SIP Advanced tab of the line. For some reason, the call coming through VM Pro used the PAID, which had the 044 prefix for the caller ID.

“Some humans would do anything to see if it was possible to do it.
If you put a large switch in some cave somewhere, with a sign on it saying 'End-of-the-World Switch. PLEASE DO NOT TOUCH'.
The paint wouldn't even have time to dry.”

Terry Pratchet

 

[outonalimb]

Thanks all for the response. It ended up being the SIP call manager we use by the SIP provider and nothing to do with the IP Office!

 

[snowman50]

Thanks for the resolution update.

This may help someone else.