Subject: [MMUSIC] File-transfer issue 37: mandating (or not) message/cpim

From: Miguel Garcia <[email-masked]>
Date: Tue, 05 Jun 2007 17:22:12 +0300

The current file-transfer draft does not explicitly indicates the 
mandate for a message/cpim wrapper. There have been discussions seeking 
for clarification on the level of requirement with respect message/cpim.

Here we rely on MSRP, which mandates the implementation of message/cpim 
but does not mandate its usage, except when one of the endpoints is a 
CPIM gateway. Should the file-transfer draft mandate it?

I think mandating message/cpim at this stage will make our life much 
easier in the future, for example, if we think of sending a file on a 
multiparty connection, of via a CPIM gateway. However, since it is not 
really mandated in MSRP, I am not sure what to say. MSRP says:

    Furthermore,
    when one endpoint of the session is a CPIM gateway, instant messages
    SHOULD be wrapped in "message/cpim" [12] bodies.  Such a gateway MUST
    include "message/cpim" as the first entry in its SDP accept-types
    attribute.  MSRP endpoints sending instant messages to a peer that
    has included "message/cpim" as the first entry in the accept-types
    attribute SHOULD encapsulate all instant message bodies in "message/
    cpim" wrappers.  All MSRP endpoints MUST support the message/cpim
    type, and SHOULD support the S/MIME[7] features of that format.

Any views on this? Whatever is the decision, we should document it.

/Miguel

-- 
Miguel A. Garcia           tel:+358-50-4804586
Nokia Siemens Networks     Espoo, Finland

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From: Ben Campbell <[email-masked]>
Date: Wed, 6 Jun 2007 08:31:55 -0500

On Jun 5, 2007, at 9:22 AM, Miguel Garcia wrote:

> mandate for a message/cpim wrapper. There have been discussions  
> seeking for clarification on the level of requirement with respect  
> message/cpim.
>
> Here we rely on MSRP, which mandates the implementation of message/ 
> cpim but does not mandate its usage, except when one of the  
> endpoints is a CPIM gateway. Should the file-transfer draft mandate  
> it?
>
> I think mandating message/cpim at this stage will make our life  
> much easier in the future, for example, if we think of sending a  
> file on a multiparty connection, of via a CPIM gateway. However,  
> since it is not really mandated in MSRP, I am not sure what to say.  
> MSRP says:
>
>    Furthermore,

I'm not sure the potential for a CPIM gateway is as strong a  
motivator as it once was. However, message/cpim serves an additional  
purpose you do not mention, namely the association of "From" and  
other metadata with the content itself. This is useful for the multi- 
party conference case even without the presence of a CPIM gateway.

But, for file transfer, I don't see a need to make this a stronger  
requirement than it is in MSRP base. My reasoning is that if either  
party needs message/cpim for one reason or another, it can signal  
that fact. If one of the parties is a conference focus or a gateway,  
it probably will--but that is not really a file-transfer issue per se.

(Note that this is not a _strong_ opinion--I would not object to  
requiring it if we otherwise have a consensus to do so.)

---

From: Miguel Garcia <[email-masked]>
Date: Wed, 06 Jun 2007 16:40:45 +0300

Hi Ben:

Thanks for the reply. I agree with you, there is a lot of 
recommendations and benefits, but not a compelling reason for mandating 
CPIM usage.

I'll check the file-transfer draft and see if we need to add a reminder 
about the statements already written in the MSRP draft.

/Miguel

Ben Campbell wrote:
>> Here we rely on MSRP, which mandates the implementation of 
>> message/cpim but does not mandate its usage, except when one of the 
>> endpoints is a CPIM gateway. Should the file-transfer draft mandate it?
>>
> I'm not sure the potential for a CPIM gateway is as strong a motivator 
> as it once was. However, message/cpim serves an additional purpose you 
> do not mention, namely the association of "From" and other metadata with 
> the content itself. This is useful for the multi-party conference case 
> even without the presence of a CPIM gateway.
> 
> party needs message/cpim for one reason or another, it can signal that 
> fact. If one of the parties is a conference focus or a gateway, it 
> probably will--but that is not really a file-transfer issue per se.
> 
>> --Miguel A. Garcia           tel:+358-50-4804586