Am 25.08.2011 11:16, schrieb Timo Reimann:
On 25.08.2011 10:31, Klaus Darilion wrote:
Am 25.08.2011 10:14, schrieb Jason Penton:
From some initial work and testing I can confirm that this works ONLY when using the top Via *without* branch tags. Not sure what impact this could have? This is because a BYE results in a different set of branch tags from the original set of invite branches - I am investigating why and how this works now.
Sure. the branch tag is a transaction identifier and must be unique in space and time. Thus, BYE must have another tag. That's why I said you have to put some data into RR cookies - this is the only data which stays the same during the dialog (except tags and call-id).
If you only want to know if an in-dialog request is from orig->term or from term->orig, then the is_direction function is already sufficient.
If you want to detect a certain spiral leg in dialog module, IMO you have to add another matching parameter (besides tags and call-id) to dialog module which will be set as RR-cookie and retrieved from Route header for in-dialog requests. Every time the initial requests spirals through the proxy, you have to add such a cookie which of course must be different to the previous inserted cookie (therefore ftag is not sufficient anymore) - either generate a random identifier or reuse some data from the message (e.g. you could copy branch-tag to RR header as it should be unique)
Let me emphasize that you don't need to add a new RR cookie: You can re-use the existing one that implements DID mode and simply extend the hash function to cover that extra value you choose. (Random number or branch parameter, as Klaus mentioned; see my comments below though.)
Indeed - I have not thought about this parameter. If it would be extended to be unique it should work - as long as the DID value in in-dialog requests is correct. Thus, DID_FALLBACK mode would not work anymore.
regards Klaus