Re: Internet Uselessness


H. Craig McKee (mckee@mitre.arpa)
Tue, 21 Jul 87 14:07:23 EDT


>As a whole, I think the internet community has been doing "clever
>engineering" for quite a number of years now. However, there
>comes a time when offered load just overwhelms the resources
>devoted to the task. We are very close to that point on the
>ARPANET, even though we just made the routing algorithm more
>"clever" and added another transcontinental trunk.

COMMENT: "Clever Engineering" - The ARPANET has been around for
17 Years and there is still a need for clever engineering;
that's discouraging.

>We are currently in the process of implementing congestion
>control in the PSNs. This should optimize the total available
>throughput of the network (at the expense of backing flows into
>source hosts if necessary).

COMMENT: With about a hundred different flavors of TCP/IP, some (many?)
of which are network-hostile, the subscriber community is forcing the
ARPANET designers to defend themselves.

>Finally, the X.25 spec really says nothing about what goes on in
>the subnet, it is just an interface spec between a DTE and its
>DCE. Internally, the PSNs use virtual circuits to support both
>AHIP (1822) and X.25 traffic while using good old dynamic
>adaptive routing to get the packets between the endpoint PSNs.
>Internally, neither AHIP nor X.25 data packets contain full
>addressing information, just the destination PSN number and a
>connection identifier at that PSN. So I guess you might say that
>we "do it right".

COMMENT: I didn't say it, Andy Malis said it: "...PSNs use virtual
circuits ... packets [DO NOT] contain full addressing information."
Then why are we flogging the network 40 octets of header per packet?

Isn't it time to swallow our embarrassment and admit that while
TCP/IP looks good on paper, in the reality of limited bandwidth and
unstable network delays, TCP/IP is, in fact, a Bad Idea? The subscriber
and network communities need to work together and come up with a scheme
that doesn't hammer the network to its knees when something goes wrong.
The Commercial/PTT networks can do it, why can't we?



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