IPv6 day and tunnels

Thu Jun 7 00:56:33 UTC 2012

Owen DeLong wrote:

>> Because bigger packets makes it rather circuit switching than
>> packet switching, which is the way to lose.

> Er... No. It's attitudes like this that killed ATM.

ATM committed suicide because its slow target speed (64Kbps
voice) and inappropriate QoS theory required small cell of
32B.

> (argument about whether the ATM cell payload should
> be 64 or 128 octets

It was between 32B and 64B.

> lead to a mathematical compromise

It is no mathematical. Instead, 48B is an algebraic mean of 32B
and 64B.

> Larger packets for sustained flows of large amounts of data
> do not make it circuit switched,

As I already gave blocking examples with problematic blocking
times, it's your problem of lack of understanding on why
circuit switching is bad.

> Admittedly, if you go to too large an MTU for your bps, you
> can create HOL blocking issues which have the same loss
> characteristics as circuit switching. However, let's say that
> anything>10ms HOL blocking is our definition of bad. At
> 10Gbps, that's 100,000 bits or 12,500 octets. At 100Gbps,
> that's 125,000 octets.

People, like you, who think 10ms blocking is fine care voice
communications only and are people for circuit switching.

We, people working on the Internet, which began as a
computer network, know 48usec can be significantly lengthy
for many computations today.

When experimental Ethernet was 3Mbps, 1500B meant 4ms blocking,
which was tolerable because computers were slow to compute
and most computation was done inside a single computer.

But, Moore's law changed everything.

Go your home of ITU.

					Masataka Ohta