Subject: [Simple] Comments to draft-stafford-simple-dmdn-00.txt

From: Miguel Garcia <[email-masked]>
Date: Mon, 05 Feb 2007 12:38:50 +0200

Hi:

So, a summary of draft-stafford-simple-dmdn is  that there is a use case 
that is not covered by the current IMDN, which is:

- An MSRP session is intercepted by a store-and-forward server. The 
sender would like to be informed when the final recipient receives or 
reads the message(s).

One first question about the use case. It appears form the text in the 
draft that the use case applies only to large messages. However, I can 
envision store-and-forward servers that store a complete MSRP session 
(not only ONE large message).

I think it is important to consider these collections of MSRP messages, 
because, imagine we add something to the CPIM headers of each MSRP SEND 
requesting delivery disposition notification, then the sender will 
receive one MESSAGE request (message 15 in Figure 1) per MSRP SEND 
request. I guess this is not reasonable.

On the other hand, if there isn't a store-and-forward server in the 
path, then there is no need for the sender to receive additional 
notifications, because the success reports in MSRP will do the job.

So, I guess where we are going is to get some sort of conditional IMDN 
for MSRP. The condition being the unavailability of the recipient to get 
the messages and a store-and-forward server storing them. This will 
obviously apply to either large messages or short ones.

Any views on this?

BR,

      Miguel
-- 
Miguel A. Garcia           tel:+358-50-4804586
sip:[email-masked]
Nokia Research Center      Helsinki, Finland

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From: "Salvatore Loreto (JO/LMF)" <[email-masked]>
Date: Mon, 05 Feb 2007 15:02:20 +0200

Hi ,

some comments in line

br
/sal

> (not only ONE large message).

you are right, if you have a store-and-forward in the path this is a
possible scenario, even if I can not imagine at present a specific use
case. (e.g. Why someone would establish a MSRP session with an off-line
user and start to chat with him?)
> request. I guess this is not reasonable.

I agree. 
A solution could be that the store-and-forward server collect all the
message in one single big message, but in this case it shouldn't be any
more a simple store-and-forward.

> obviously apply to either large messages or short ones.

I don't have a clear view on this,
but maybe if we introduce a indication that an MRSP session is
established for just sending one message, this indication could help.

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From: Miguel Garcia <[email-masked]>
Date: Mon, 05 Feb 2007 15:17:01 +0200

Some inline discussion:

> user and start to chat with him?)

Well, look at commercial systems. They do it. I can do it. I actually do 
it... I establish a session with some offline friend to send a few 
messages, or pending items, such as my latest pictures. This is a real 
use case.

> more a simple store-and-forward.

Certainly that is one possibility. Another one is to promote the IMDN 
request to the INVITE, and provide a "session-level" IMDN.

In any case, I think these should be dependent on the presence of a 
store-and-forward server in the path.

/Miguel

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From: "Salvatore Loreto (JO/LMF)" <[email-masked]>
Date: Mon, 05 Feb 2007 15:39:43 +0200

Hi Miguel,

see the discussion on line

br
/sal

> messages, or pending items, such as my latest pictures. This is a real 

Yes I am aware that some IM programs behave in this way.
What I don't see is the necessity to have or provide a delivery
notification in this scenario, and in fact they don't do.
But I understand and fully agree with your concern about adding some
header for Deliver Notification in the CPIM headers of each MSRP SEND
request.

> request to the INVITE, and provide a "session-level" IMDN.

yes, promoting the IMDN request to the INVITE could work in both the
scenario: the only one large message and several short/normal messages.
It can say to the final recipient to send an IMDN to the original sender
when as soon as he has received the whole large message or all the short
messages. For example as soon the store and forward server close the
MSRP session.
But promoting the IMDN request to the INVITE levels means we have also
put at this level same information about the original sender. what do
you think about?

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From: Miguel Garcia <[email-masked]>
Date: Mon, 05 Feb 2007 15:42:54 +0200

> put at this level same information about the original sender. what do

I think it is not a straight forward option. At least, I would like to 
re-use IMDN as much as possible. Including IMDN requests in INVITE 
requests is not feasible today, since IMDN requests are embedded in CPIM 
messages, and we don't have CPIM in INVITE requests.

/Miguel

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From: "Nancy Greene \(QA/EMC\)" <[email-masked]>
Date: Wed, 7 Feb 2007 01:59:15 -0500

We can have CPIM in an MSRP SEND though, so that is where we should be
concentrating. Especially if we have this large message mode where only
one message is sent within the SIP session and that is the one that is
actually deferred.

Nancy 

-----Original Message-----
From: Miguel Garcia [mailto:[email-masked]] 
Sent: Monday, February 05, 2007 8:43 AM
To: Salvatore Loreto (JO/LMF)
Cc: [email-masked]'
Subject: Re: [Simple] Comments to draft-stafford-simple-dmdn-00.txt

/Miguel

---

From: "Nancy Greene \(QA/EMC\)" <[email-masked]>
Date: Wed, 7 Feb 2007 01:59:15 -0500

Nancy 

-----Original Message-----
From: Miguel Garcia [mailto:[email-masked]] 
Sent: Monday, February 05, 2007 8:43 AM
To: Salvatore Loreto (JO/LMF)
Cc: [email-masked]'
Subject: Re: [Simple] Comments to draft-stafford-simple-dmdn-00.txt

/Miguel