[asterisk-users] Passing a variable downstream to an IAX server

[A J Stiles]

Apologies if this is a really stupid n00b question, but I don't seem to be 
able to find an answer anywhere.

Is it possible somehow to pass a channel variable to another Asterisk server 
down an IAX trunk?

I have 2 machines; one which is fitted with an ISDN card to make outside calls 
via an E1 line, and another with a GSM card to make outside calls via the 
mobile network.  The GSM machine gets some calls passed onto it by a command 
like Dial(IAX2/user:pass at host.cc/number) .

This works nicely, but I want to know:  is there any way to pass on a variable  
(already set in the dialplan before the Dial() occurs)  to the downstream 
server?

It's a single numeric value that I want to pass on, so I guess in the worst 
case it could be sent within the actual number e.g. by appending * and the 
data to the extension number and then using CUT() on the downstream server.  
But is there a less-ugly method that I am just missing?

-- 
AJS

Answers come *after* questions.