Re: [rtcweb] Constraint to disable IPv6 candidate collection

[Roman Shpount <[e-mail]>]

On Wed, Apr 8, 2015 at 5:20 AM, Iñaki Baz Castillo <[e-mail]> wrote:

> 2015-04-08 0:28 GMT+02:00 Roman Shpount <[e-mail]>:
> > it would be better to define a constraint that can be used to suppress
> > IPv6 candidate collection
>
> I'm against any approach or option that treats IPv6 as "optional" or
> less important than IPv4. IMHO if Firefox fails (even) to parse IPv6
> candidates, the vendor should fix it.
>
> Said that, it is very *sad* that Firefox fails to parse an SDP due to
> an IPv6 address in the c= line. Come on! this is about a grammar
> defined more than 15 years ago!
>

We will retest Firefox 37 for IPv6, but this was really not the reason for
the constraint, but an illustration of the problem. This issue was brought
up as one of the examples of SDP mucking that is currently required to deal
with interop issues. Until IPv6 is implemented by default in both Chrome
and  Firefox, we will be in the state of transition. During this transition
all surrounding services would need to be updated to IPv6 and tested with
the browser implementations. Until this happens, IPv6 as a feature would
need to be disabled in the JavaScript client code. One way to do this is
via constraints, and Chrome already provides such a constraint. I assume
when Firefox will introduce IPv6 support, some sort of similar constraint
is going to be provided there as well. If such constraint will not be
provided, we will need to do SDP mucking, which everyone assumes is bad.

So, in the real world outside of standard committees and labs, each new
feature which is introduced needs to be controlled in such a way that it
can be deployed into production in gradual and managed manner. Since IPv6
is not a feature which was implemented from the start by the browsers, we
now need to manage the transition. This will take at least another year, or
at least this is how long it will take for Firefox 36 and older
installations to clear out. I understand that this is a short time frame in
comparison with the lifetime of the specification, but some solution for
managing the transition to IPv6 would be appreciated. I understand that in
this particular case a client side SDP filter for old Firefox versions
which removes IPv6 candidates and IPv6 address from the c= line can be
clunky but acceptable answer to this problem.

Regards,
_____________
Roman Shpount