Subject: [MMUSIC] BUNDLE (pre-5): New Answerer text

From: Christer Holmberg <[email-masked]>
Date: Thu, 19 Sep 2013 10:23:07 +0000

Hi,

Based on the new BUNDLE Offerer text, I also modified (and, hopefully clarified) the Answerer text.

In addition, the new text also covers 'bundle-only' m- lines.

Comments are welcome.

Regards,

Christer

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6.5.  SDP Answerer Procedures

6.5.1.  Answerer Bundle Address Selection and Usage

6.5.1.1.  Offerer Bundle Address Selection

When an Answerer generates an Answer that contains a BUNDLE group,
the Answer MUST select the Offerer's BUNDLE address. The first mid
value in the SDP group:BUNDLE attribute mid list of the Offer
represents the address which the Offerer wishes the Answer to
select as the Offerer's BUNDLE address [ref-to-offer-prec].

The Answerer SHOULD select the address represented by the first mid
value, unless the Answerer in the associated Answer will rejects the
"m=" line associated with the mid value [ref], or remove the "m=" line
from the BUNDLE group [ref] from the BUNDLE group. In such case the
Answerer MUST select an address associated with the next mid value in
the SDP group:BUNDLE attribute mid list of the Offer.

In the SDP Answer, the Answerer MUST place the mid value associated with
the selected Offerer's BUNDLE address first in the SDP group:BUNDLE
attribute mid list associated with the BUNDLE group.

Section 10.1 shows an example of an Offerer's BUNDLE address
selection.

6.5.1.2.  Anwerer Bundle Address Selection

When an Answerer creates an Answer that contains a BUNDLE group,
the Answerer MUST assign a local shared address, the Answerer's BUNDLE
address, to each "m=" line within the BUNDLE group.

The Answerer is allowed to change its BUNDLE address in any SDP
Answer.

The Answerer MUST NOT assign a shared address, that it has assigned
to an "m=" line within a BUNDLE group, to an "m=" line outside
the BUNDLE group.

Section 10.1 shows an example of an Answerer's local BUNDLE address
selection.

6.5.2.  Moving A Media Description Out Of A BUNDLE Group

When an Answerer generates an Answer, in which an "m=" line is moved
out of a BUNDLE group, the Answerer assigns an address to the moved
"m=" line based on the type of address that the Offerer assigned
to the associated "m=" line in the associated Offer, as described below.

If the Offerer assigned a shared address to the "m=" line, the
answerer MUST reject the moved "m=" line, according to the procedures
in Section 6.5.3.

If the Offerer assigned a 'bundle-only' attribute to the "m=" line,
the Answerer MUST reject the moved "m=" line, according to the procedures
in Section 6.5.3.

If the Offerer assigned a unique address to the "m=" line, the Answer
MUST assign a unique address to the moved "m=" line.

In addition, in either case above, the Answerer MUST NOT anymore
include a mid value, representing the "m=" line, in the SDP
group:BUNDLE attribute list associated with the BUNDLE group.

6.5.3.  Rejecting A Media Description In A BUNDLE Group

When an Answerer generates an Answer, in which an "m=" line associated
with a BUNDLE group is rejected, the Answerer MUST assign an address
with a zero port value to the rejected "m=" line, according to the
procedures in [RFC3264]. In addition, the Answerer MUST NOT anymore
include a mid value, representing the "m=" line, in the SDP group:BUNDLE
attribute midlist associated with the BUNDLE group.

---

From: Harald Alvestrand <[email-masked]>
Date: Sat, 21 Sep 2013 08:39:45 +0200

> In addition, the new text also covers 'bundle-only' m- lines.
Some grammar nits.
> Christer
"from the BUNDLE group" is repeated twice.
> the SDP group:BUNDLE attribute mid list of the Offer.
This should be "an address associated with the first unrejected MID that 
remains in the BUNDLE group".
Otherwise, rejecting MID #1 and #2 would leave you in an undefined state.

> _______________________________________________
> mmusic mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/mmusic

---

From: Christer Holmberg <[email-masked]>
Date: Sat, 21 Sep 2013 08:34:56 +0000

Hi Harald,

Thanks for your comments!

Regards,

Christer

Lähettäjä: [email-masked] [mailto:[email-masked]] Puolesta Harald Alvestrand
Lähetetty: 21. syyskuuta 2013 9:40
Vastaanottaja: [email-masked]
Aihe: Re: [MMUSIC] BUNDLE (pre-5): New Answerer text

Comments are welcome.
Some grammar nits.

Regards,

Christer

---------------------

Answerer MUST select an address associated with the next mid value in
the SDP group:BUNDLE attribute mid list of the Offer.
This should be "an address associated with the first unrejected MID that remains in the BUNDLE group".
Otherwise, rejecting MID #1 and #2 would leave you in an undefined state.

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