Subject: Re: [SPIRITS] Archie

From: Igor Faynberg <[email-masked]>
Date: Wed, 06 Dec 2000 21:03:46 -0500

First, thanks to Lawrence for submitting the drawing!

If it comes for replacing the one made by Lev for the Architecture
documents, I see a few minor-to-medium problems (like jibing the
terminology with what is presently in the text), which I believe can be
worked out, and one major problem.

While in PINT we had decided (and I agreed to that decision and still
stand by it!) that there is a need for a gateway and no-man interface
between the Internet and PSTN, in SPIRITS we have decided that the
SPIRITS client is located in the PSTN. (The extensive discussion took
place at the Washington meeting, and the subseqent agreement made later
firmly.) This is really the only thing that makes the present
architecture not so symmetric, and this is why it would be impossible to
reconcile the two drawings as they stand now.

For the protocol work, it does not matter much whether the connection is
over the gateway or not, but having an extra interface had caused some
problem in understanding PINT. As we produce the Informational
Architecture RFC for SPIRITS (which we had not done in the case of
PINT), we have a chance to make things clear. Beyond the pedagogical
argument, it is simply incomprehensible how an IN-supported service
originating in the PSTN ends up on the "SPIRITS client gateway." I
talked to Lev briefly to clarify a few things that made him make a
decision and to refresh the history. Even though this has been a clear
decision, I think it is not a bad idea to revisit it during the meeting.
It is a very straight-forward thing, so I don't expect much disagreement
or much time spent on the subject.

And--back to Jim Buller's earlier question (a very good one!) on
splitting PINT and SPIRITS. Prior to talking to Soren in September, I
saw no need for this, but his requirement that the IN be used ONLY to
initiate the service is something that we must respect. I am still
expecting some text for that in the overall requirements, and I intend
to state that while the joint PINT/SPIRITS package is needed for many
important services, it is NOT a necessary requirement. In other words, a
one-message NOTIFY thing is an acceptable solution for a (rather small)
SPIRITS implementation.

I doubt I will be able to talk much on the list before the meeting... My
day job has been rather overwhelming lately. But I am looking forward to
meet you all in San Diego and continue in a good spirit of cooperation. 
And lots of spirits drinking after the SPIRITS meeting!

With best regards,

Igor

Lawrence Conroy wrote:
> 
> Hi folks,
> This list does not allow .PDF to be included, so herewith:
> 
>    .............                 ................
>    . A.N.Other .                 .Separate  End .
>    . Client    .                 .User Interface.
>    .(e.g. Web  .                 ................
>    . Browser)  .                        .
>    .............                        .
>          .                              .
>     Protocol A                      Protocol B
>          .                              .
>    :...........:                 :.............:
>    :    ALG    :                 :     ALG     :
>    : e.g. Web  :                 : e.g.Protocol:
>    :   Server  :                 : Y Client    :
>     ...........                   .............
>     -----------                   -------------
>    !PINT Client!                 !  SPIRITS    !
>    !-----------!                 !  Server     !
>         !                        !-------------!
>     PINT Service                       !
>     Protocol                     SPIRITS Protocol
>         !                              !
>    .............                 ...............
>    : optional  :                 : optional    :
>    : PINT Proxy:                 :SPIRITS Proxy:
>    : /Registrar:                 : /Registrar  :
>    :...........:                 :.............:
>         !                              !
>        PSP                       SPIRITS Protocol
>         !                              !
>    !-----------!                 !--------------!
>    !PINT Server!                 !SPIRITS Client!       PSTN-
> \/! (Gateway) !\/\/\/\/\/\/\/\/\! (Gateway)    !\/\/\/ Internet
>    !           !                 !              !       Boundary
>    !-----------!                 !--------------!
>          ?                              ?
>     Some Protocol                Some other Protocol
>     _____?_____                   ______?_______
>    : Executive :                 :  Initiative  :
>    : System    :                 :  System      :
>    :e.g. SSF,  :                 :e.g. SSF, SCF :
>    :SCF, etc.  :                 :    etc.      :
>    :-----------:                 :--------------:
>          |                              |
>          |                              |
>        0---0        GSTN Handset      0---0
>         / \         or MS/UE           / \
>        -----                          -----
> 
> Note: Protocol A might be used if user interface for PINT service requests
> is (for example) a Web form. This would be submitted to a Web Server that
> used an internal PINT Client to initiate a PINT Service request. It is not
> required (for example, a program could "talk" PSP directly).
> 
> Protocol B is fairly similar; it MAY be used between an end User Interface
> and an Application Layer Gateway that included both a SPIRITS Server and
> an end node for this other program. It is not required; the SPIRITS Server
> may execute the requested service directly (with any needed end User
> Interface).
> 
> Regards, Lawrence
> 
> _______________________________________________
> SPIRITS mailing list
> [email-masked]
> http://lists.bell-labs.com/mailman/listinfo/spirits

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