Subject: PINT is another story...

From: [email-masked] (Lawrence Conroy)
Date: Tue, 30 Mar 1999 21:34:02 +0100

In answer to Igor's story, a little story of my own, (unfortunately a sore
point):

I'm at an Airport, and have been told by the ticket clerk that the flight I
want to take is full. I ask to be put on the "waitlist". The implication is
that I've subscribed to the status "not full" on the flight. If susequently
I receive a message that a seat is now available, I will react to this,
going onto the flight.

It's true to say that my action is in response to a notification I
received, but that isn't the whole story. I believe that it would be
imprecise to suggest that the "get onto flight" action on my part is
invoked by that notification; it's part of a longer transaction that I
initiated.

Now consider WHY I'm suffering at the Airport. My Boss asked me to get to
wherever, NOW, so I've turned up hoping to change my flight. In this case,
a request (ha!) from my Boss has initiated my airport transaction. This is
not just a notification from my Boss, he's started the whole sorry process.

Both this and the message that a seat is available trigger some activity on
my part; one, however, is a notification that I have requested, whilst the
other is a service request that I most certainly haven't.

If, as happens, my Boss has asked me to tell him whather or not I'm on the
flight, then I have to send this information back to him; in effect, he's
subscribed to the "Lawrence is on the way" status.

As far as I'm concerned, the trigger for this grief is receiving an email
from my Secretary; the details of what triggered her to send the email are
unclear to me, other than saying "the Boss sez..." (authorization, if you
like).

In our terms: imagine that the ticket clerk and P.A. system at the airport
are considered part of the PSTN, and I'm on the Internet.

In this case the subscription and their subsequent notification are part of
PINT; it's in the draft and may even be of wider interest in the MMUSIC
world.

The message from my Boss may NOT be part of PINT, as I received an email
that my Secretary sent me in reaction to a phone call from my Boss asking
her to pass on to me that I should be elsewhere. It's a "reverse PINT" or
TniP service ->request<-. IMHO, it isn't a notification.

When I call him to say I'm on the flight, the message that I'm on my way is
also not currently within PINT, as it's a notification send back to him via
a phone call. Even if it triggers some actions on his part, IMHO it's not a
service request; he asked to be informed and I'm complying with this
request.

In this scenario, using the word "Notification" in place of the word
"Message" is, IMHO, imprecise, when we're talking about two separate
(albeit nested) monitoring or control relationships. Igor proposes a much
tighter definition of the word "Notification"; looks good to me.

The current PINT draft talks about subscribing to notifications of events
in the PSTN. I'm a little uncomfortable about the reverse of this situation
(i.e. a PSTN/I.N. entity subscribing to notification of events that occur
in the Internet) being included within PINT; it makes the "bite" somewhat
large.

Igor's story also describes the word "trigger". This is specific to
requests that come from the PSTN world (where this is almost a reserved
word) thus I take this to mean that we should be careful of using the word
"Trigger" for different meanings in any work we take forward in PIN, or
PITS as Igor would have it, or the equally appropriate description Jim gave
in his last mailing.

In the PINT drafts, for example, we have been careful to use the word
service request for a similar initiating message. Thus I wholeheartedly
agree with Igor that the PIN services are those that are triggered from the
PSTN up into the Internet.

Now we only have to agree on whether or not we have complete symmetry with
PINT by incorporating notifications and responses back from the Internet
into the PSTN within PIN (in the same way that notifications and responses
back from the PSTN are included within PINT). I hope so.

All the best, Lawrence
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| Lawrence Conroy,    | "These Opinions must be mine, 'cos if they    |
| Roke Manor Research |  were my Company's they'd charge you for them"|
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From: Alec Brusilovsky <[email-masked]>
Date: Tue, 30 Mar 1999 15:41:10 -0500

Lawrence,

I hope you will agree that we do not have enough time to study long chain of
events leading to us suffering at the Airports. My hint would be to start with
"In the beginning God created the heaven and the earth..."

Meanwhile, we have to select classic PIN services and focus on the PIN services
requirements.
In order to do that we have to agree on what will constitute PIN service.
By focusing on the core PIN service and leaving subscription alone we can do
that much easier.

-Alec