RE: Draft on Callout Protocol Requirements

--On Friday, November 23, 2001 15:03 -0800 Reinaldo Penno<reinaldo_penno(_at_)nortelnetworks(_dot_)com> wrote:

-----Original Message-----
From: Ian Cooper [mailto:ian(_at_)the-coopers(_dot_)org]
Sent: Wednesday, November 21, 2001 3:52 PM
To: 'OPES Group'
Cc: Penno, Reinaldo [SC9:T327:EXCH]
Subject: RE: Draft on Callout Protocol Requirements

I agree that the wording isn't too good with respect to your
comment.  That
said, it's possible that by adding the intermediary to offer the OPES
service that network becomes a Content Network.  (And on that
note I think
the authors/editors need to be a little more careful about
the distinction
of content networks and CDNs as they are typically understood.)

But yes, if you only have plain IP there's no device that OPES could
connect to in order to provide its services (OK, I'm not
avoiding that
issue, am I).  You need an application layer intermediary
(and for the
protocols proposed that would tend to be called a proxy) on
which to do the
value-added services that OPES enables.


hummm. Let's see a real example. My broadband provider is ATT and I have
webmail. If AT&T offers anti-virus with a intermediary (proxy) and remote
call-out server (anti-virus scanner), does ATT as a whole suddenly
becomes a CDN? A Content Network?

Another example. In my house I run a web server with a reverse proxy. If
in this (OPES) reverse proxy I offer some service, for instance language
translation, does my home network becomes a CDN? Does ATT as a whole
becomes indirectly a CDN? A Content Network?

I appreciate your point and that the phrase "Content Network" might implysome additional things (certainly CDN implies more and in both of theexamples above neither becomes a CDN in my view). The problem is that Ithink we need some phrase to help identify these "special content adaptingnetworks"... "Content Network" works to a degree.

As I said, "it's possible that by adding the intermediary... that networkbecomes a Content Network."

If you have an exceptionally limited case, as in your examples, I wouldn'tsuggest that's a Content Network, no. (And that's most likely becauseyou've only got one service being undertaken.)

As for the examples you give, those services appear to be provided by thesame business entities as the core services. So no, I don't think thatadding new devices to perform transformations within their own networks ontheir own content really makes them Content Networks.

> Another option to be explored is when you ask for a
service, you do not
> know a priori how the content will be transformed. You just ask for
> ad-insertion, not for a specific ad. So when call out send the first
> response with an ad-insertion, he also might say "and by
the way, apply
> the same ad to all HTTP requests from network A.B.C.D to
network F.G.H.I
> for a period of time T".

Of course, the problem with pipelining is that things can get
delayed in
the pipe, so responses become serial.

As to Reinaldo's suggestion above... I don't really see how
that logic can
be passed back in a way that can be used in quite that way.
Caching of
transformations may be appropriate if these can be addressed
appropriate,
of course.


I do not see any difficulty doing this. It all depends on the remote
call-out protocol. Maybe you are thinking in terms of a specific call-out
protocol.

Perhaps, though I'm not sure if you're addressing one or the other or bothof my comments.

I believe I might be thinking slightly different to you regarding thecomment "apply the same ad to all HTTP requests". If the ads are beinginserted by a callout server then I don't immediately see how the devicethat used the callout would be able to cache all the logic to do that. Ofcourse, there are examples where this would be possible, and the disconnecthere is probably because we're thinking of different examples.