On Thu, 2012-08-09 at 16:03 +0200, Olle E. Johansson wrote:

I am not in favour of a new module. Like GRUU, this is just optional behaviour based on the signalling....

My concern is just the amount of complex Kamailio configuration required for something like Outbound. It's likely to be very messy and hard for people to use. But if you think it is practical, I don't have a problem trying it that way.

There are going to be quite a number of (hopefully small) changes to the existing modules (path, registrar, rr, and usrloc at least) anyway.

The record_route() APIs need to be updated to make the userinfo settable from kamailio.cfg (at least you can already add parameters)
The add_path() APIs need to be updated to let parameters be added (for example ";ob" - at least you can already set the userinfo)
The logic to decide to use outbound for requests from clients should be manageable as a route
The logic to do the routing back to clients, sending the 430 etc, should be manageable as a route
Flow token generation/decode/validation is going to be tricky as new APIs will be needed for at least base64 encode, base64 decode, HMAC-SHA1-80 - and string manipulation in kamailio.cfg is a pain. Perhaps a set of flow-token specific APIs to wrapper all of these things (in one of the utils modules) would be better?
A new API will be required to determine whether a connection exists (based on input of IP address, port, and protocol) - unless trying to send the request and just catching/translating the error to a 430 is OK
I think the new lookup(), lookup_next_dest(), managing the AVPs for this and removing bindings from the location table all do need to be new functions in the registrar module

Have I missed anything in that list?

-- 
Peter Dunkley
Technical Director
Crocodile RCS Ltd