Re: [MMUSIC] ICE-SIP-SDP: Concluding ICE statement

[Roman Shpount <[e-mail]>]

Hi Christer,

On Tue, Jul 23, 2019 at 1:48 AM Christer Holmberg <
[e-mail]> wrote:

> Again, the text says:
>
>
>
>   “Once the state of each check list is Completed, and if the agent is
>
>    the controlling agent, it nominates a candidate pair [RFC8445] and
>
>    checks for each data stream whether the nominated pair matches the
>
>    default candidate pair.”
>
>
>
> The text indicates that the agent nominates a candidate pairs once a check
> list is Completed. That is wrong. A check list becomes Completed **after**
> a candidate pair has been successfully nominated. Do you agree with that?
>
>
>
I would agree that this text can be better. In general, in English two
verbs in present tense in a sentence do not establish the temporal
relationship between the actions. Better text would say something like:

Once the state of each check list is Completed, and if the agent is the
controlling agent, it *should have nominated* a candidate pair [RFC8445]
and checks for each data stream whether the nominated pair matches the
default candidate pair.


There are still a few issues with this:


1. If aggressive nomination is used, multiple candidate pairs can be
nominated for the same component of a given data stream. Considering that
aggressive nomination is deprecated, nothing implementing ice-sip-sdp
should be doing this and only one candidate pair (per component per data
stream) should be nominated. I do not think this is a problem.


2. This language does not take into account that state for some check lists
can be Failed. It is unclear if new offer should always be generated in
this case or only generated if ice2 options is not set. I am not sure what
is the use case for partial ICE failure. I have never dealt with this in
practice. If you feel this needs to be fixed, please propose the language.


Best Regards,
_____________
Roman Shpount