PBX-to-PBX Internet trunking success with ENUM and h.323 - a first

[Michael Haberler <]

in the preparation for the VoiP/ENUM Tutorial at RIPE-46, we had a little 
H.323 ENUM bakeoff.

Participating were the nic.at Asterisk Linux IP PBX in Vienna, and the 
www.innovaphone.com ISDN/IP PBX in Germany. Asterisk was massaged by Otmar 
Lendl who had just implementend H.323 ENUM lookup in the Asterisk call 
processing. Martin Streller of Innovaphone is the implementor of the ENUM 
code in their PBX.

Martin and Otmar got transparent Internet trunking with ENUM to work 
between an Asterisk and an IP-3000 - you dial a number with a DDI extension 
on the other PBX as you normally would - NO ACCESS CODES OR TRUNK 
PREFIXES!! -  as there's an ENUM entry and both PBXes do ENUM DNS queries 
in outbound call processing the call is delivered via IP (h.323 in their case).

An interesting aspect of the Innovaphone device is the fact that it can do 
drop & insert - it has a network-side and a user-side ISDN port; if you 
plug it between the telco line and a vanilla PBX, it can act as a least 
cost routing device based on ENUM lookups - on outbound calls coming from 
the PBX, it will lookup the number in the DNS and divert to the Internet - 
otherwise the call will go to the telco in the upstream port. Which means 
that your old PBX could use ENUM in & outbound unchanged.

I would expect this to become more widespread as PBXes with IP & ENUM clue 
appear on the market.

BTW Innvoaphone has a very elegant scheme were configuring an extension i 
the PBX automatically produces a corresponding DNS entry - the PBX itself 
also acts as an ENUM DNS server for the pilot number and extensions. 
Currently their boxes are h.323 only but they plan to implement a SIP stack 
as well.


-Michael