Thursday, February 26, 2009

Transparent IAM Front and Center

The transparent IAM project has stepped into the priority 1 position because of a deadline in early March for a test of number portability in France.

March 15 looms large - .us corporate tax returns are due then. Then April 15 follows for .us person tax returns. These are unyielding distractions.

The transparent IAM feature now sends and receives stringified IAMs in the ISUPinRDNIS string that is copied to the the Asterisk RDNIS channel variable. Transparent IAM processing is optional per trunk group. The last big thing to do before releasing the feature to field test is to develop a new outbound transparent IAM parser. This new parser is aware of how to pick apart the outbound transparent IAM and use the harvested parts to assemble a new IAM. Here is the process being considered. The term sIAM is short for "stringified IAM" which is another term for the transparent IAM.

1. CIC value is determined by trunk group specified by dialplan and
the outbound hunt algo. in ss7boost
2. message type is IAM
3. fixed mandatory variables are taken from the sIAM
4. called number taken from dialplan
5. calling number taken from dialplan
6. redirection parms built from RED parms in ISUPinRDNIS from dialplan
if present, else take from sIAM if present
7. generic number parm built from GEN parms in ISUPinRDNIS from
dialplan if present, else take from sIAM if present
8. add on all other optional variable length parms in sIAM that have
not been used or overlayed already

This plan has been reviewed and approved by a reliable partner and user in France so it's a good bet that this will be very close to what's needed.