Lossy cogent p2p experiences?

Mon Sep 4 11:27:35 UTC 2023

Masataka Ohta wrote on 04/09/2023 12:04:
> Are you saying you thought a 100G Ethernet link actually consisting
> of 4 parallel 25G links, which is an example of "equal speed multi
> parallel point to point links", were relying on hashing?

this is an excellent example of what we're not talking about in this thread.

A 100G serdes is an unbuffered mechanism which includes a PLL, and this 
allows the style of clock/signal synchronisation required for the 
deserialised 4x25G lanes to be reserialised at the far end.  This is one 
of the mechanisms used for packet / cell / bit spray, and it works 
really well.

This thread is talking about buffered transmission links on routers / 
switches on systems which provide no clocking synchronisation and not 
even a guarantee that the bearer circuits have comparable latencies. 
ECMP / hash based load balancing is a crock, no doubt about it; it's 
just less crocked than other approaches where there are no guarantees 
about device and bearer circuit behaviour.

Nick