911 dialing help- IP office 500 v2 ver 11.0

[TIgerV]

I have the above system, connected PRI to an adtran 908e SIP gateway.
Whenever I call 911 from certain extensions, it send the header FROM: 911@<sip domain>. TO:911@<sip domain>. All other calls go out with the proper caller ID. eg: 26012345486@<sipdomain>.
ONE extension calls 911 properly with the proper caller id.
Problem is that the SIP provider rejects the outgoing FROM header.
I know the Adtran is getting the outbound caller ID from the IPOffice, but where do I make it so that it has the proper header?
Can I tell the Adtran "When you see 911 as callerid change it to xxxxxxxxxx"?
I have tried MANY combinations, and just can't get it. Further, I see NO difference in the one station that works and the others.

--TIger

 

[Ekster]

In The UK, caller ID for emergency service calls is passed in the PAID Header. Could that be the case here?

 

[derfloh]

That sound like a bad configured dial short code.