Outbound Routes question UKdi


Sorry, I am a bit of newbie to Asterisk trying to configure outbound routes in an Asterisk based appliance. I am in the UK

I have tried to setup the the following outbound patterns on an analogue FXO PSTN line.

As I understand _9 (outgoing line) plus “.” is a catchall for any following numbers

These work for most calls but I am struggling trying to make a call like


which is a standard mobile number in the UK, lets say it is +4407123456789, not real number, but for example.

Can the “+” not be parsed by asterisk for international calls even if nationally? Much of our address books have +44 numbers in the UK as it makes routing when we are abroad from the UK easier from mobile phones and these could be copied and pasted easily to a softphone, like “Telephone” app on Mac OS X

Is this a UK PSTN issue?

For instance dialling
Replies “the number can’t be recognised”
routed via the FX0 port
This is obviously the UK telcom BT in the UK replying with this

Replies “the number can’t be recognised”
routed via the FX0 port
This is obviously the UK telcom BT in the UK replying with this

connects as you would expect?
routed via the FX0 port over BT

Am I missing something very obvious?

Many Thanks


Caution: outbound route is a FreePBX term, and FreePBX is not supported here.

This isn’t a valid UK mobile number. Although it has been common practice to misrepresent international numbers as +44 (0)…, the correct notation is +44… (People did this to avoid providing a separate national number.)

The use of + is not specific to the UK.

What sort of FXO port is this? Analogue lines cannot dial +. Nor actually can ISDN lines. ISDN lines have a type of number field, with might be “national number dialled”, in which case you would strip the number back to 7123456798, “international number dialled”, in which case you would strip it to 447123456789, or “other”, in which case you would use 00447123456789 or 07123456789.

Analogue lines only basically take the other format. Your reference to FXO implies an analogue line. Note that for most landlines, although this is being phased out, you can omit the area code, for national numbers, when it is the same as that of the caller, so you can start London numbers, dialled from London numbers with the 7, and leave out the 020.

You would always strip the level 9 digit.

Best practice is to canonicalise numbers to a standard format, so probably convert everything to 0044 format then replace that with just 0 just before dialling.

Also note that analogue line suffer from glare, and from a lack of good answer and disconnect supervision.

I’ll recommend that you skip the 9 and just make these rules
assuming that you provider want E.164 format


The OP seems to be using an analogue line on the BT network. It’s impossible to dial “+”, so it is not using E.164. It will have the same rules as ordinary, domestic phones; you will need to dial 0 before national numbers, 00 before international numbers, it is permissible, but weird, to dial 0044 before national numbers, and it is permissible, but archaic, in many places, to omit the 0 and area code in front of numbers in the same area code.

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