Subject: RE: Is WAP mobile Internet??

From: Vernon Schryver <[email-masked]>
Date: Wed, 5 Jul 2000 12:02:33 -0600 (MDT)

> > > > think we mean having unincumbered availability of the common application
> > > > protocols, email, http, ftp, ssh, ...  
> > >
> > > that's not quite enough; in the UK we're seeing cable-modem ISPs
> > > attempt to restrict services to those applications, or to a subset of 
> > > those applications (lotsa luck setting up an http server or using
> > > ssh.)
> > > ...
> > 
> > and also like AOL's redirecting proxies for out-bound SMTP?
> > and the port-25 filtering of many ISP's including UUNET?

> From: Rick H Wesson <[email-masked]>

> would pacbell filtering all multicast at all CPE equipemt fall into your 
> bucket, where do you draw the line?

I think it depends on motives.  Port 25 filtering and SMTP redirecting
proxies exist for the same reasons slumlords put bulletproof glass in
their windows and chainlink fencing on their balconies instead of evicting
or otherwise dealing with criminals.  Port 25 filtering and SMTP
redirecting is easier but more expensive in the long run than enforcing
strong terms of service, such as $500/day clean-up fees.  HTTP redirecting
proxies sometimes have much worse, completely intolerable motives, from
unvarnish government censorship of political speech to inserting ads.

Historically multicast was filtered because routers didn't know about it
and those operating them no better informed and caring even less.  Today,
I can still imagine some technical motives for filtering multicast packets.
They would be defensible for a while.  I know nothing about what PacBell
is doing now, but they're filtering class-D addresses for any except real
technical reasons that they honestly plan to fix, then they are not selling
Internet access.  If they are advertising otherwise, then appropriate
legal steps should be taken.

Instead of silly blathering about getting wireless phones and SuperHypeWay
access to the billions of people who currently have neither those modern
necessities, reasonable food or shelter, or even per capita incomes of
$1000/year, those who care about the Internet should be worrying about
the efforts of the old media and communications outfits to transform the
Internet into something they know, whether POTS or TV.

Vernon Schryver    [email-masked]

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From: Joe Touch <[email-masked]>
Date: Thu, 06 Jul 2000 09:42:01 -0700

> > bucket, where do you draw the line?

At IP, as Bob Braden said.

SMTP is _over_ IP.

Multicast _redefines_ IP (or portions of the address space thereof); it
could be argued that a service provider sells 'Internet' without selling
multicast IP.

Joe

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From: Masataka Ohta <[email-masked]>
Date: Fri, 7 Jul 2000 10:25:10 +0859 ()

Joe;

> At IP, as Bob Braden said.

Wrong. RFC821 says:

   SMTP is independent of the particular transmission subsystem and
   requires only a reliable ordered data stream channel.  Appendices A,
   B, C, and D describe the use of SMTP with various transport services.
   A Glossary provides the definitions of terms as used in this
   document.

> could be argued that a service provider sells 'Internet' without selling

See STD1 for a list of "required" protocols.

							Masataka Ohta

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From: Joe Touch <[email-masked]>
Date: Thu, 06 Jul 2000 18:49:23 -0700

>    A Glossary provides the definitions of terms as used in this

Appendix A is SMTP over TCP (over IP). (I was implying that it was on
TOP of IP, not that it was exclusively on top of IP).

SMTP in the Internet is, by definition, over IP. STD1 defined only one
required reliable ordered data stream protocol - TCP.

> See STD1 for a list of "required" protocols.

Multicasting is RFC1112, one of the 'required' protocols.

On page 1 of that RFC:   

	Level 0: no support for IP multicasting

   There is, at this time, no requirement that all IP implementations
   support IP multicasting.  Level 0 hosts will, in general, be
   unaffected by multicast activity.  The only exception arises on some
   types of local network, where the presence of level 1 or 2 hosts may
   cause misdelivery of multicast IP datagrams to level 0 hosts.  Such
   datagrams can easily be identified by the presence of a class D IP
   address in their destination address field; they should be quietly
   discarded by hosts that do not support IP multicasting. 

Interestingly, the RFC indicates 'should be quietly dropped' where not
supported. There is no requirement that they not be dropped, or that the
dropping be quiet.

Joe

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From: Masataka Ohta <[email-masked]>
Date: Fri, 7 Jul 2000 11:21:44 +0859 ()

Joe;

> required reliable ordered data stream protocol - TCP.

What is your point?

Are you saying that, in the Internet, there is some application/transport
protocols not over IP but SMTP is exclusively over IP?

> Multicasting is RFC1112, one of the 'required' protocols.

In RFC 2400, the last STD1 which included information on requirement
levels, it is a "recommended", not "required" protocol.

I wonder why the information is missing in the recent STD1.

							Masataka Ohta