Re: TCP/IP Terms

[Bill Sommerfeld]

I fail to see why this is such a pressing issue.  To be completely
unambiguous, you need to name the protocol.  That identifies the
layer, and then "packet" or "datagram" or what-have-you is
unambiguous.

- Bill

TCP/IP Terms

[Bill Cunningham]

I think the main goal is to compete with OSI's much more defined model. I
for one, don't want to see OSI overtake in any way TCP/IP, even in
definitions. But Bill S. is correct, all you have to do is mention the layer
and protocol. But there are so many new protocol's out there now, as I've
mentioned before PPP is an example written since rfc 1122-23. It is now its
own suite, with a family of link and network control protocols.

RE: TCP/IP Terms

[Michel Py]

Bill,

This slide is confusing, for sure. The reason I posted the link was the
comparison between the OSI and the TCP/IP models.

Michel.

> From: Bill Cunningham [mailto:[EMAIL PROTECTED]]
> http://dast.nlanr.net/Training/DCWJuly99/kai_tcpip/sld008.htm
> I looked at this page of one of the links you sent me. Notice
> at the Internet and Transport levels it simply says, Application
> data (datagram ?), TCP header, could this be a datagram, or
> maybe a packet. Then at the Internet level, application data,
> TCP header and IP header. Now according to rfc 1122, we know that -
> o application data, tcp header
> o application data, tcp header, and ip header.
> Are both datagrams. Wow IMHO what a mix up. Unless you know the
> name of the protocol and where you know (or think) it is in
> TCP/IP, you're lost.

Re: TCP/IP Terms

[Robert Elz]

Date:Mon, 30 Sep 2002 11:01:56 -0400
From:"Bill Cunningham" <[EMAIL PROTECTED]>
Message-ID:  <000701c26892$52428400$5844903f@a>

  | I think the main goal is to compete with OSI's much more defined model.

Why?

  | I for one, don't want to see OSI overtake in any way TCP/IP, even in
  | definitions.

I'd actually much prefer for OSI to win the "war of the definitions".
Rigid definitions tend to constrain thinking to fit into the patterns
defined.   We're much better off just having a rough idea what things
mean when it gets to this level.

kre

RE: TCP/IP Terms

[Michel Py]

Bill,

> Bill Cunningham wrote:
> I think the main goal is to compete with
> OSI's much more defined model.

What's wrong with the OSI model?

Michel.

RE: TCP/IP Terms

[Christian Huitema]

> I'd actually much prefer for OSI to win the "war of the definitions".
> Rigid definitions tend to constrain thinking to fit into the patterns
> defined.   We're much better off just having a rough idea what things
> mean when it gets to this level.

While the concept of layering is fine (more or less), the specific
layers adopted in the OSI model have only a moderate relation with
actual practice, and are a poor fit for the Internet architecture.
Specifically:

1) OSI's modeling of the lower layers was driven by the need to
accommodate X.25 split between physical transmission, HDLC/LAP-B, and
virtual circuits. This does not describe well the situation in the
Internet, in which IP is often layered on top of what OSI considers a
network layer, e.g. X.25 or ATM; the same problem arose when attempting
to layer CLNP on top of these networks; this led to Byzantine
discussions of sub-layers 3a, 3b and 3c. 

2) OSI's modeling of the upper layers was driven by the need to
accommodate the Teletex application, which used a pass-through transport
(class zero) and required a "session" layer to handle check-pointing and
restart. In the real world, check-pointing and other synchronization
tasks are performed a layer above marshalling and un-marshalling, i.e.
above the presentation layer. Again, OSI's response to the reality check
has been a Byzantine decomposition of the application layer into
"application service elements" that would what we usually understand as
"session control". 

The main problem with OSI is that they drew the layers in 1980, i.e.
before the client server architectures based on RPC stabilized, before
we gained experience with internetworking. The TCP-IP architecture
choice of having an internet layer on top of a subnet layer, and single
layer for the application were, at the time, much more practical. They
withstood time much better.

-- Christian Huitema

Re: TCP/IP Terms

[Bill Cunningham]

>
>   | I for one, don't want to see OSI overtake in any way TCP/IP, even in
>   | definitions.
>
> I'd actually much prefer for OSI to win the "war of the definitions".
> Rigid definitions tend to constrain thinking to fit into the patterns
> defined.   We're much better off just having a rough idea what things
> mean when it gets to this level.
>
> kre

I don't want to see TCP/IP be overtaken either. It's the root of the
Internet, not OSI or anything else. Maybe TCP/IP needs to be more
competative.
>
>

Re: TCP/IP Terms

[Bill Cunningham]

- Original Message -
From: "Michel Py" <[EMAIL PROTECTED]>
To: "Bill Cunningham" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Monday, September 30, 2002 1:28 PM
Subject: RE: TCP/IP Terms


> Bill,
>
> > Bill Cunningham wrote:
> > I think the main goal is to compete with
> > OSI's much more defined model.
>
> What's wrong with the OSI model?
>
> Michel.

In and of itself, nothing. But it's not the Internet's true roots, and I
don't think it works as well for the net's architecture.
>

Re: TCP/IP Terms

[Brian Bisaillon]

In the four-layer model, "Application" encompasses "Layer 7", "Layer 6", and "Layer 5" 
from the seven-layer OSI model.

I always considered TCP headers or IP headers as data formats that make up the overall 
protocol. They have to be processed. Therefore, they are essentially "application 
data".

Anyway, it gets confusing when you start trying to differentiate between what is an 
algorithm, what is a data format, what is a file format, and what is a protocol. The 
terms should be a lot clearer. For instance, some people think algorithms and 
protocols are the same. Other people think data formats and protocols are the same. 
Additionally, some people have trouble differentiating between what is a data format 
and a file format. Does data format mean the data is generated on-the-fly whereas a 
file format is a static file? In the logical sense, something like XML still has to be 
processed so to me it's just another data format but if you think of it in its 
"statically and physically stored" sense it's a file format. Mind boggling... :-)

Brian B.

>>> "Bill Cunningham" <[EMAIL PROTECTED]> 09/30/02 12:34AM >>>
http://dast.nlanr.net/Training/DCWJuly99/kai_tcpip/sld008.htm

I looked at this page of one of the links you sent me. Notice at the
Internet and Transport levels it simply says, Application data (datagram ?),
TCP header, could this be a datagram, or maybe a packet. Then at the
Internet level, application data, TCP header and IP header. Now according to
rfc 1122, we know that -
 o application data, tcp header
 o application data, tcp header, and ip header.

Are both datagrams. Wow IMHO what a mix up. Unless you know the name of the
protocol and where you know (or think) it is in TCP/IP, you're lost.

-
This message was passed through [EMAIL PROTECTED], which
is a sublist of [EMAIL PROTECTED] Not all messages are passed.
Decisions on what to pass are made solely by Raffaele D'Albenzio.

Re: TCP/IP Terms

[Joe Touch]

Bill Cunningham wrote:
> - Original Message -
> From: "Michel Py" <[EMAIL PROTECTED]>
> To: "Bill Cunningham" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
> Sent: Monday, September 30, 2002 1:28 PM
> Subject: RE: TCP/IP Terms
>
>
>
>>Bill,
>>
>>
>>>Bill Cunningham wrote:
>>>I think the main goal is to compete with
>>>OSI's much more defined model.
>>
>>What's wrong with the OSI model?

See Padlipsky's "Elements of Network Style", again available in print.
It's as relevent now as it was when it was written in 1984:
http://www.iuniverse.com/bookstore/book_detail.asp?isbn=0%2D595%2D08879%2D1

Joe

RE: Report on Peering and Transit Economics (etc)

[Bill Strahm]

All I have to say is "WOW" A three page executive summary.  I am afraid
to read the rest... Guess I will have to see what is going on especially
when they start talking about ICANN (At the VERY bottom) I'd love to
know how that fits into Peering and Transit economics


Bill

-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of
Gordon Cook
Sent: Sunday, September 29, 2002 9:46 AM
To: [EMAIL PROTECTED]
Subject: Report on Peering and Transit Economics (etc)


I have published an extremely detailed report on the economics, 
technology, and politics of peering and transit.  At 
http://cookreport.com/11.08-09.shtml you will find the complete 
introductory article, contents and  list of 25 contributors to the 
effort.  The report centers on interviews with Bill Woodcock, an 
essay / critique by Farooq Hussain and an edited version of the 6 
weeks of discussion by the 25 contributors.

I  include here the executive summary from the report.  This summary 
is not on my web site and I am not posting it elsewhere.

Executive Summary

Whither the Policy, Technology, and Economics of the Interconnection 
of the Internet?

The collapse of the industry and of the price of bandwidth is 
bringing significant changes into the ways in which ISPs and the 
remnants of the Old Guard of Tier 1 backbones interconnect.

Some people who are affected have made some significant steps in 
using NetFlow data in developing tools that are being refined into 
what can function as bandwidth cost management systems.  We identify 
several explorations being taken in this direction and explore what 
looks to be the most refined developed by Bill Woodcock with the 
assistance of Alex Tudor at Agilent Labs.

Bill has developed a philosophy of interconnection that appears to 
have a sound  business model behind it.  Bill's approach was 
developed from the point of view of a small ISP that needs to 
understand with as much precision as possible what it does cost to 
get its bandwidth delivered.  His model says that ISPs that are 
multi-homed and have their own leased line customers need to peer as 
much and as cheaply as possible.  They also need to have two reliable 
transit providers in case one fails.  As long as their peering can 
cut over to transit if it fails, he points out that economics would 
seem to demand delivery of as much bandwidth by cheap peering as 
possible to cut down on the requirement for expensive transit 
bandwidth.

ISPs need to avoid local loop charges from their LECs and acquire 
their own back haul to an exchange for inexpensive peering and if 
possible a different exchange or exchanges for more reliable transit. 
In order to figure how to most cost effectively architect their 
networks they need to take and manipulate NetFlow samples of their 
traffic in order to identify potential new peers via a study of the 
traffic being delivered by their transit providers.  If they have 
automated tools to take samples from appropriate points, they can 
over time get clear pictures of how their traffic is evolving through 
actual NetFlow path analysis.

But Woodcock's colleagues seem to agree that he has done something 
unique.  He explains it in writing for the first time in this issue 
of the COOK Report.  Namely he does what he calls synthetic path 
analysis by tacking his actual path data and doing a series of "what 
if" transformations on that data.  With the help of Alex Tudor from 
Agilent labs he explains using actual data from January 31 2002 how 
this synthetic analysis can be applied so that for the first time an 
ISP, by plugging circuit cost data into its modeling software, can 
know how much it really does cost to deliver its bits.

These ideas are new. While our experts agreed that perhaps 100 ISPs 
may be doing some form of actual NetFlow data analysis, virtually no 
one except Woodcock had done the synthetic path analysis.  Avi 
Freedman in his position as Chief Network Scientist at Akamai has had 
ample occasion to use network routing and DNS to figure out data 
flows.  After studying Bill Woodcock's explanation found that he had 
evidence from his own related experience that indicated Bill's 
approach seemed valid. He points out that since 1999 he has been 
doing a "what if" analysis on "Akamai flows" similar to Woodcock's 
synthetic path analysis on router flows.

Our 50,000 word eight week long discussion involving 25 different 
people contains a quite interesting dialog between the Avi and Bill 
as they compare their approaches to the problem and conclude that the 
ideas appear to be valid. However, we must also point out that Bill's 
synthetic path analysis is not meant to be  the sole criterion on 
which to base peering and transit decisions.  Once they have 
identified potentially good peers, ISPs will find that factors of 
geography and costs of interconnection at various exchanges may 
become decisive factors in making their final decisions.

Although the largest c

Re: TCP/IP Terms

[Ari Ollikainen]

At 1:30 PM -0700 9/30/02, Joe Touch wrote:
>>>
Bill Cunningham wrote:
I think the main goal is to compete with
OSI's much more defined model.
>>>
>>>What's wrong with the OSI model?
>
>See Padlipsky's "Elements of Network Style", again available in print.
>It's as relevent now as it was when it was written in 1984:
>http://www.iuniverse.com/bookstore/book_detail.asp?isbn=0%2D595%2D08879%2D1

Or, at the very least, read RFC 871 ...

RE: TCP/IP Terms

[Michel Py]

kre / Bill,

>>> kre wrote:
>>> I'd actually much prefer for OSI to win the "war of the
>>> definitions". Rigid definitions tend to constrain thinking
>>> to fit into the patterns defined. We're much better off
>>> just having a rough idea what things mean when it gets to
>>> this level.

>> Bill Cunningham wrote:
>> I for one, don't want to see OSI overtake in any way TCP/IP,
>> even in definitions.

> I don't want to see TCP/IP be overtaken either.

Nobody's ever suggested this. 


> kre wrote:
> It's the root of the Internet, not OSI or anything else.
> Maybe TCP/IP needs to be more competative.

In terms of design, if you do TCP/IP *only* design, the TCP/IP model is
probably enough. However, the Internet is not only TCP/IP. Carriers, for
example, don't care much if their fiber transports TCP/IP or IPX or
voice or video or GigE.

And, there are complex multi-protocol networks that a) don't use only
TCP/IP and b) would not be able to use the TCP/IP model anyway because
it's too simple.

Also, the Internet can be used to tunnel other protocols. How would you
describe the subtilities of Token-Ring DLSW+ with the TCP/IP model?

I understand that we are the *Internet* Engineering Task Force. However,
I don't see the incompatibility between TCP/IP and the OSI model.

The bottom line is: lots of people are going to continue using the OSI
model. We don't need two different models.

Michel.

RE: APEX

[Michel Py]

Dave,

Could you share what motivated the choice of the word "datagram" for
APEX? What puzzles me is that APEX rides on top of TCP, a
connection-oriented protocol. APEX might be stateless, but if it rides
on top of TCP how could you call it connectionless (which would be why
one uses the word "datagram") ?

Thanks
Michel.

RE: TCP/IP Terms

[Chris Evans]

Thanks man.. that clear up confusion on PPP ! 

>mentioned before PPP is an example written since rfc 1122-23. It is 
>now its
>own suite, with a family of link and network control protocols.
>
>

The dismal science meets computer science - The obvious thought experiment

[Dan Kolis]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

On [EMAIL PROTECTED]

Hmmm. Very interesting material here on economics and traffic
analysis. I remember when I heard as a young teen Kruschev and
Kennedy agreed and primarily designed Intelsat, that anything upon
which those guys agreed with certainty must be wrong. (doesn't really
matter who decided this. The point is a framework for a thought
experiment about Internet economics).

Now, the argument I recall WAY BACK then; (ex post facto to me, but
this also doesn't matter), is that the earth was DEFICIENT in that
the moon wasn't a good enough natural reflector for unlimited telcom
traffic by using it as a reflector. This is the thought experiment I
(either) recalled or dreamt up during a discussion. -So-
to remedy this deficientcy, institutions of a non profit and non
discriminitory nature (Intelsat) came to be as an alleged no profit,
dogooder driven institution. Of course it got, fat, overpriced,
arrogant and bad at technology.


"The Communications Satellite Act of 1962 was passed and the new
organization came into 
being in March of 1963 with a charter to establish in conjunction
with other countries 
a global communications satellite system to serve the needs of all
countries, especially 
the underdeveloped, and to hopefully, through its creation,
contribute to world peace 
and understanding. 

http://www.clarkeinstitute.com/lecture4.html

Of course, the underdeveloped world never got anything whatsoever,
but an endless expensive committee blundering along for 11 years and
subsidizing a lot of probably entertaining travel:

http://www.peak.sfu.ca/cmass/issue1/access.html

Anyway, nothing new there. I leave it to you to decide on the "peace
and understanding" part. Also "serve the needs of all countries", is
a bit of a hint, too. How about the people in them?

But, *if* the moon allowed reliable low attenuation telecom; (or if
the atmosphere simply permitted it by some other physical law
unmediated by humans). Its nearly impossible to understand if
Internet would be sustainable. Without a rare resource; (transponder,
fiber, etc) to allocate via a cost, its possible the initial anarchy
would yield to some licensing system; but whatever system it would be
would still leave it brutally overutilized and barely functional. And
investment to make alternatives would be impoverished, as they would
always face the prospect of competing with a free system. The only
reserved parking spot carefully considered is the *last* spot.

Now in the book "Technologies of freedom"; the mightly intellect of
Illithel de sola Pool is even stuck on resolving much of this.

Now; you PROBABLY EXPECT SOME ALLEGED MASTER PLAN  from
a smarty pants guy like me, but, ah no. Instead the possibilty Global
Crossing, Worldcom, etc fiber operators will operate the businesses
without replacing / sustaining the investment, and the emergence of
Low Earth orbiting satelittes carrying TCP/IP for next to nothing;
(or nothing as part of some value added package). Is going to happen.
The reference condition for any theory of telecom should be that
transport itself doesn't cost anything, and its all still
sustainable. 

This has hints in it: http://www.isen.com/

AKA the "rise of the stupid network". 

(1) But the reference condition is a network so stupid its: infinite
in bandwidth, instant, 100% available, secure, and free. 

"We first encountered this formulation in the September 2001 issue of
Roxane 
Googin's High Tech Observer. She wrote, "The perfect network is
perfectly plain,
and perfectly extensible. That means it is also the perfect capital
repellant, 
[which] implies a guaranteed loss to network operators, but a boon to
the 
services on the 'ends'."

http://netparadox.com/

I promised no master plan, but it seems like its at least possible to
have an endless stack of value added services absorb the
infrastructure costs. Maybe there should be a structural floor for
all the infrastrucutre services, and it simply be replacement at life
end for the hardware? I don't know. When Atomic energy was proffered,
it was going to be "electricity too cheap to meter", so this reductio
ad absurdum tends to show up; and when done on a large scale (aka
California power), hurt people.

Sometimes, I wish I hadn't napped quite so much in economic's class,
sometimes. )But the room was always so darn warm) !

Regards,
Dan



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Re: TCP/IP Terms

[Randy Bush]

> I don't want to see TCP/IP be overtaken either. It's the root of the
> Internet, not OSI

you have a problem with your email system.  ten year old mail is
being resent from you, but somehow it has current dates.

randy

Re: TCP/IP Terms

[Bill Cunningham]

- Original Message -
From: "Ari Ollikainen" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, September 30, 2002 6:46 PM
Subject: Re: TCP/IP Terms


> At 1:30 PM -0700 9/30/02, Joe Touch wrote:
> >>>
> Bill Cunningham wrote:
> I think the main goal is to compete with
> OSI's much more defined model.
> >>>
> >>>What's wrong with the OSI model?
> >
> >See Padlipsky's "Elements of Network Style", again available in print.
> >It's as relevent now as it was when it was written in 1984:
>
>http://www.iuniverse.com/bookstore/book_detail.asp?isbn=0%2D595%2D08879%2D1
>
> Or, at the very least, read RFC 871 ...

Thanks Ari, I'll take a look at it.
>
>
>

Re: TCP/IP Terms

[Bill Cunningham]

> In terms of design, if you do TCP/IP *only* design, the TCP/IP model is
> probably enough. However, the Internet is not only TCP/IP. Carriers, for
> example, don't care much if their fiber transports TCP/IP or IPX or
> voice or video or GigE.
>
> And, there are complex multi-protocol networks that a) don't use only
> TCP/IP and b) would not be able to use the TCP/IP model anyway because
> it's too simple.
>
> Also, the Internet can be used to tunnel other protocols. How would you
> describe the subtilities of Token-Ring DLSW+ with the TCP/IP model?
>
> I understand that we are the *Internet* Engineering Task Force. However,
> I don't see the incompatibility between TCP/IP and the OSI model.
>
> The bottom line is: lots of people are going to continue using the OSI
> model. We don't need two different models.
>
> Michel.

Fine let them use OSI or whatever they choose. But if TCP/IP has
incompatibilies with token-ring LANS, this
should probably be worked on. I believe in freedom to
choose whatever model you wish, but TCP/IP is the Internet's model. Why does
TCP/IP have trouble passing a token ring around hosts? I've never really got
into that issue. I thought TCP/IP worked fine in Intranets.
>
>

Re: APEX

[Bill Cunningham]

- Original Message -
From: "Michel Py" <[EMAIL PROTECTED]>
To: "Dave Crocker" <[EMAIL PROTECTED]>
Cc: "Bill Cunningham" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Monday, September 30, 2002 7:41 PM
Subject: RE: APEX


> Dave,
>
> Could you share what motivated the choice of the word "datagram" for
> APEX? What puzzles me is that APEX rides on top of TCP, a
> connection-oriented protocol. APEX might be stateless, but if it rides
> on top of TCP how could you call it connectionless (which would be why
> one uses the word "datagram") ?
>
> Thanks
> Michel.

Sounds like it should ride on a faster UDP connection,
if CRC and error checking isn't necessary, but that's probably why he chose
TCP, a secure transfer.
>
>
>

RE: TCP/IP Terms

[Michel Py]

Bill,

>> Michel Py wrote:
>> The bottom line is: lots of people are going to continue
>> using the OSI model. We don't need two different models.

> Fine let them use OSI or whatever they choose. But if TCP/IP has
> incompatibilies with token-ring LANS, this should probably be
> worked on. I believe in freedom to choose whatever model you wish,
> but TCP/IP is the Internet's model. Why does TCP/IP have trouble
> passing a token ring around hosts? I've never really got into that
> issue. I thought TCP/IP worked fine in Intranets.

It's not a matter of compatibility, it's a matter of semantics. The
point is *not* if TCP/IP works fine in Intranets; it does and it is
becoming the only protocol suite on Intranets as well (faster in my
dreams than in reality).

The point I am trying (with difficulties ;-) to make here is: The OSI
model as of today is a conceptual model. In the past, some good stuff
came out of it and some real junk too; that was in the past. Today, if
your protocol maps nicely to it, fine. If it does not, though.

That being said, the Internet is not the only network out there and even
on the Internet itself there are parts where the 4 1/2 layers TCP/IP
model is way too simple.

Take a reality check: go to Border's or any bookstore and browse books
about networking or internetworking. Tell me if you find the TCP/IP
model there or the OSI model.

As I said before, the time to design according to a model is way passed.
What I do today as a protocol designer is based on my and other people's
experience, not on a model that was invented 20 years ago before nobody
could really envision today's Internet.

In other words: I am not preaching for the ISO or any other model being
a set of design guidelines. What I am trying to say is that when
defining terms (read the subject of this thread) the OSI model is more
precise than the TCP/IP one and is still the one used by people
including myself that have a broader horizon than TCP/IP or the
Internet.

Michel.