Re: [MMUSIC] Offer/Answer PT Questions - text proposal

[Christer Holmberg <[e-mail]>]

Hi,

>>>"The scope of a mapping from a particular dynamic payload type number to a codec
>>>(or codec configuration) is for a given RTP media flow direction within a session.
>>>The same dynamic payload type number can be mapped to another codec in another RTP
>>>media flow direction within the same session. The mapping MUST NOT change to a different
>>>coded (or coded configuration) for the duration of a session. Eventhough not recommended,
>>>for a given direction, multiple dynamic payload type numbers can be mapped to the
>>>same codec (or codec configuration).
>>>
>>> I think MUST NOT is too strict for this rule and SHOULD NOT should be sufficient. In current implementation this
>>> rule is often ignored. The worst thing that can happen is a small media disruption, but with the careful
>>> implementation, even that will not occur in most use cases.
>>
>> There may also be implementations that DO implement the rule. SHOULD NOT means that endpoints have to be prepared to handle it.
>
> I guess what I am trying to say is these implementations really should not be enforcing this rule. There is no technical reason for strict enforcement and this will break things during the interop.
>
>> Is there really a reason why we should allow it?
>
> It is impossible to implement 3pcc with this rule in place. 

In that case, maybe should allow it ONLY when an endpoint does not have any knowledge about the mappings, and give 3pcc as an example.

Regards,

Christer