ATM (was Re: too many routes)

Carmen Hillenburg carmenh at
Fri Sep 12 05:50:43 UTC 1997

Sean M. Doran wrote:

> BTW, your formatting sucks to the point that your note is
> unreadable and unquotable without fmt(1) or fill-paragraph.

 Sorry, bad program to send from ;{

>So anyway, as I was saying, I'm ignorant about such matters.

Cute. ;) Its nice to know you have a sense of humor !

>Oh now THERE's a reliable source.  "Hi my name is Frank
> and ATM will Just Work.  Hi my name is Warren and ATM is
> fantastic.".  Ugh.  (kent bait kent bait kent bait)

 Not my point, I was just quoting my "source" of timings, nothing more.

>At higher bandwidths bits are shorter not faster.

  Yes, but at lower bandwidth they are spaced further apart.

>Repeat that several times.

  Yes, do.

>Whether you are signalling at 300bps or at
>293875983758917538924372589bps, the start of the first bit
>arrives at the same time.

 I was talking about a total performance increased experienced by more
bandwidth, not *just* latency.
BTW the total transmission time is still reduced, my original point. I
was careful to note the resultant transmission time, not latency.

 Also, if the cell entered the net to carry the "first bit" before it's
natural TAT......

>Um, no it doesn't.  As with all demand-cached forwarding
>schemes you have to process a packet heavily when you have
>a cache miss.

 You are right. I was not accurate on full implementation detail, but
the concept was there. I *really* must remember *not* to use
simplifications for brevity in the nanog list. But, the description was
not intended as an RFC. I was only noting the advantage to not needing
to look up where to send a packet , * every time *.

> MPLS is conceptually related, btw.

   Interesting. PS. I am a supporter.

>P.S.: You have some very entertaining and unique expansion
>      of a number of acronyms in general and relating to
>        ATM in particular.  I'm curious how you expand "PDH".
>        Personally I favour "Pretty Damn Historical",
>        although other epithets come to mind.

   I repeat, I will NEVER, NEVER, NEVER, over simplify for brevity to
the nanog again.
Bad Richard, Bad! (But each one gave you the general idea, didn't it.)

  I rather liked your response(s), it was informative. I still hold to
my point, though.

 Now rather than fire a response to all those flames, one at a time....

To One individual:

  Yes, I used some terms from Frame Relay, instead of ATM. (OOPs! I work
with all the above, and it was the end of a 10 hour day) And yes, the
acronyms are in error in literal expansion, however, not in concept.
They perform the same BASIC function.
Never, never, never again....
  And to another, I did not claim that the speed of light is NOT a
factor, just not the only one.
And since I cannot change the speed of light .....
Bad! Never, Never..

(One guy hated a 12ms difference between my "on the cuff estimate", and
his calculation of the RTT.) Boy, THAT invalidates ATM.
Never, Never, Never...

> I wasn't around for the invention of statistical muxing,
>but I'm sure there are some people here who could clarify
>with first-hand knowledge (and I'll take email from you,
>thanks :) ).

  Neither was I. However, I wasn't being quite that literal. I will
accept that I presented an inaccuracy.
SDM just allowed more diverse use of a given voice circuit.

A lot of this chain-flame is my fault, a little too tired.., and not
exacting detail. However,
Sorry, I still hold to ATM being superior for WAN, and possibly exchange

This does not mean ATM will hold as well as other technologies when
seriously OVERSUBSCRIBED. (Now, what fool would do that .) But, I should
note that during the recent "brown outs"  it was not the ATM NAP's that
were collapsing.
(Not that some peoples ports weren't lossy)

 Many of you picked at details you could find wrong, from spelling to
12ms differences in earth round trip time. etc. I hope some of you noted
what was right. Those points never seem to get "cut and pasted."  Some
times you just can't see the forest for the all tree's in the way..

  And boy there were a LOT of tree's.

A) ATM is better.
B) No its not!
A) Yes it is!
B) No its not!
A) Yes it is !
B) Your hair is died !!
A) Uhhh...Its only grecian formula...
B) Is that your natural color ?
A) Well, no, I told you I use greci...
B) uh-huh, SEE! ATM isn't better!
A) sigh.......

 Wasn't this on Monty Python ?

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