[Asterisk-Users] international caller id on UK (BT) PRI

[Phil Blundell]

When a call arrives on our PRI from a UK domestic number, the presented
caller ID looks something like "1223123456".  In my dialplan, I stick
"90" on the front in order to turn this into a valid number for outward
dialling, and everything works fine.

However, when a call comes in from an international number, I need to
add an extra zero -- that is, "491234123456" needs to have "900" added
on the front to make it valid.  Is there some Asterisk variable I can
inspect to find out whether the presented CLI is using a national or
international number plan?

thanks

p.