[cisco-voip] "Caller ID" on forwarded call

[Andreas Sikkema]

Hi,

I've been looking all over but I can't find a definitive answer to the 
following. I'm running a SIP based VoIP platform connected to the PSTN via 

a number of plain EURO ISDN30's. End users on the platform can configure 
their SIP account to forward all incoming calls to a third party. A calls 
B where B is located on my SIP platform. B forwards the call 
(unconditional, no answer, etc) to C. Changing the normal Caller ID is 
not an option on the call to C unfortunately, due to carrier restrictions.

Is there a way to add an IE to the outgoing ISDN messages to the PSTN 
containing 
the originator of the call? I seem to remember something called 
"redirected number" but I can't find any definitive references to it. 

The second question is can the AS5350 add such a header on a plain ISDN30 
based on some SIP header? Which header?

Thanks!

-- 
Andreas Sikkema