Re: [sr-dev] ideas on dialog spiral distinction

> 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)