Re: [MMUSIC] Trickle ICE for SIP Questions

[Christer Holmberg <[e-mail]>]

Hi,

>>>> How is this better than PRACK?
>>>
>>> Well, you don't have to worry about supporting offers and answers in the PRACK (which could indeed be a pain).
>>
>> In my years of "PRACK experience", PRACK itself (for the purpose of acknowledging reliable 18x responses) has never been a 
>> problem. But, I agree there could be issues when it is used for O/A - especially if one wants to reject an offer. In my experience, however, 
>> offers in PRACK are normally used e.g. to change pre-condition state, and/or to remove codecs, so the likelihood of rejection based on the SDP content should be rather small.
>>
>> There are also implementations that don't accept offers in PRACK to 
>> begin with, but I think that goes under "bad implementation" :)
>>
>> Having said that, not specific to trickle ICE, if O/A is a show 
>> stopper for the community to use PRACK,
>
> Well, speaking as an implementor, I can completely see how many would feel uneasy about adding this to working implementations. It basically means adding some additional complexity with no actual benefit in return.
>
>> maybe that is something we need to look into on a more general level.
>
> You mean something like PRACK-lite that doesn't have offer answer? This sounds like something that could be relatively straightforward to specify. It would basically 
> have to mimic PRACK but remove the part that talks about the additional O/A possibilities.

It could perhaps even be a request without a response, similar to ACK, which would make it even more "lite". When the UAS receives it, it simply ceases the transmission of the 18x.

Regards,

Christer