Subject: [MMUSIC] Should draft-dtls-sdp-23 be a normative update to RFC4572

From: Roman Shpount <[email-masked]>
Date: Tue, 18 Apr 2017 15:17:53 -0400

Re-sending to mmusic list and changing the title:

On Tue, Apr 18, 2017 at 10:51 AM, Paul Kyzivat <[email-masked]>
wrote:

> Section 8 has a number of normative requirements around the use of
> 'tls-id'. This seems to break interoperability with existing
> implementations that follow RFC4572.
>
> What is the intent here regarding interoperability with RFC4572?
> Perhaps this doc should now also be a formal update to that.
>

Should we reword those requirements that they only apply when tls-id is
used?

So instead of

If an offerer or answerer inserts an SDP 'connection' attribute with a
'new' value in the offer/answer, the offerer/answerer MUST also insert an
SDP 'tls-id' attribute with a new unique value.

We would say:

If an offerer or answerer inserts an SDP 'connection' attribute with a
'new' value in the offer/answer and also provides SDP 'tls-id' attribute,
the value of tls-id' attribute MUST be new and unique.

And instead of

If an offerer or answerer inserts an SDP 'connection' attribute with a
'existing' value in the offer/answer, and if a previously established TLS
connection exists, the offerer/answerer MUST also insert an SDP 'tls-id'
attribute with the previously assigned value in the offer/answer.

We would say

If an offerer or answerer inserts an SDP 'connection' attribute with a
'existing' value in the offer/answer, if a previously established TLS
connection exists, and if the offerer/answerer provided 'tls-id' value in
the previous offer/answer which established this TLS connection,
the offerer/answerer MUST also insert an SDP 'tls-id' attribute with the
previously assigned value in the offer/answer.

If we reword these statements like this, do we still need to specify that
this document updates RFC4572?

Regards,
_____________
Roman Shpount

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From: Martin Thomson <[email-masked]>
Date: Wed, 19 Apr 2017 09:39:51 +1000

I agree with Roman, we can and should just ensure that this is a new
feature, not a rewrite.  I don't think that we need to invalidate RFC
4572 implementations.  This is an enhancement (a very useful one, but
an enhancement only).

p.s., Any updating should be done to RFC 8122 now, if at all.  That
probably removes any heat from the discussion as pertains to updating
of old specs.

On 19 April 2017 at 05:17, Roman Shpount <[email-masked]> wrote:
>> 'tls-id'. This seems to break interoperability with existing implementations
>> that follow RFC4572.
>>
> If an offerer or answerer inserts an SDP 'connection' attribute with a 'new'
> value in the offer/answer, the offerer/answerer MUST also insert an SDP
> 'tls-id' attribute with a new unique value.
>
> We would say:
>
> If an offerer or answerer inserts an SDP 'connection' attribute with a 'new'
> value in the offer/answer and also provides SDP 'tls-id' attribute, the
> value of tls-id' attribute MUST be new and unique.
>
> And instead of
>
> the previous offer/answer which established this TLS connection, the
> offerer/answerer MUST also insert an SDP 'tls-id' attribute with the
> _______________________________________________
> mmusic mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/mmusic
>

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From: Christer Holmberg <[email-masked]>
Date: Wed, 19 Apr 2017 07:45:09 +0000

Hi,

I agree that the draft should be an update to 8122 (not 4572). That was
actually my intention, but I forgot about it.

The changes suggested by Paul look good.

Regards,

Christer

On 19/04/17 02:39, "Martin Thomson" <[email-masked]> wrote:

>>'new'
>>'new'

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From: Christer Holmberg <[email-masked]>
Date: Wed, 19 Apr 2017 07:51:45 +0000

Hi,

Sorry, I messed up the RFCs.

I do NOT think we need to update 8122. The text says that the new
procedures are used ³in conjunction² with the 8122 procedures, and the
text suggested by Paul fits into that.

Regards,

Christer

On 19/04/17 10:45, "mmusic on behalf of Christer Holmberg"
<[email-masked] on behalf of [email-masked]>

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From: Christer Holmberg <[email-masked]>
Date: Wed, 19 Apr 2017 07:54:11 +0000

Text suggested by Roman, that is… I really need a cup of coffee :)