PSTN line issue

Ok this is not an Asterisk issue as per say but just wondering if anyone else has experienced this issue before, basically when a number calls in the number is being altered this is before hitting the asterisk server. we know its not an asterisk issue as we have tested it.

the problem seems to be with BT side the numbers are stripping the 0 at the start of the telephone number so we see on the display side +7 111 111 111 or variation on it this happens with landlines to when they call in we would see +1745 111111 some times we are seeing an extra 001745 111 111 which is a nightmare because the numbers come up country code wise as Russian or US numbers… the other problem we have been told by a few customers they are getting an invalid number response when dialling in as if the number in is being altered somewhere…

just wondering if anyone has seen this happen before again its nothing to do with the asterisk server we know that works fine and we have tested that with other lines (and sip providers) If anyone has ever seen this before with BT just be nice to know did BT ever get it fixed as we are currently on 7 months of hassle and we cant just drop the line as it’s a well established number…


I don’t think there is a connection between the cid that you see when someone calls you and what your customers say.
For the cid problem check the asteirsk cli to see what you are getting and if it is being altered somewhere in the dialplan, if not then you cannot do anything. It’s a problem in the provider and they have to fix it.

Now related to the invalid number response, do you use an pstn card to connect the pstn line or a gateway?

Normally when you get mangled callier ID on the UK PSTN it is because the call is originating via VoIP. This is very common for junk callers, particularly those that ignore TPS registrations.

the problem is these numbers are random in nature some cases the same customer can call 5 minutes later and the number reaches us unaltered. to top it off all these numbers are from registered O2, Orange, BT, Sky… so on and so on but they are random in some cases the numbers come through fine then others mangled or not at all with the invalid number issue.


Re you lines Alog? or ISDN? you dnt say.

if alog could be getting a digit dropped reciving caller id if isdn look at the debug of an inbound call.

if its that much of an issue port the number out to a voip supplier, would only take a few days if a single number.