Re: [sipcore] Draft new version: draft-holmberg-sipcore-proxy-feature

[Christer Holmberg <[e-mail]>]

Hi, 

>I'm pointing out, just as a participant, that you will have a 
>harder time drumming up interest for a niche mechanism than 
>you will for a general one.

I think a number of people have already shown interest for this.

>Another hurdle you're going to face is harmonizing your 
>proposal with RFC 5897. All three of your examples rely on 
>doing, just about as vigorously as possible, precisely what 
>RFC 5897 says not to do.

Feature tags indicate support of a capability. EVERY feature tag does that - even if inserted in a Contact header field by a UA - and the feature tag specification needs to define the meaning of that capability.

The important thing is that it cannot be assumed that other entities understand the meaning of the feature tag in order to progress a call (in such cases you will also need an option-tag, inserted in a Require/Proxy-Require header field).

Regards,

Christer