Re: constant FEC errors juniper mpc10e 400g

[Saku Ytti <saku () ytti fi>]

On Sun, 21 Apr 2024 at 09:05, Mark Tinka <mark@tinka.africa> wrote:

> Technically, what you are describing is EoS (Ethernet over SONET, Ethernet over SDH), which is not the same as 
> WAN-PHY (although the working groups that developed these nearly confused each other in the process, ANSI/ITU for the 
> former vs. IEEE for the latter).
>
> WAN-PHY was developed to be operated across multiple vendors over different media... SONET/SDH, DWDM, 
> IP/MPLS/Ethernet devices and even dark fibre. The goal of WAN-PHY was to deliver a low-cost Ethernet interface that 
> was SONET/SDH-compatible, as EoS interfaces were too costly for operators and their customers.
>
> As we saw in real life, 10GE ports out-sold STM-64/OC-192 ports, as networks replaced SONET/SDH backbones with DWDM 
> and OTN.

Key difference being, WAN-PHY does not provide synchronous timing, so
it's not SDH/SONET compatible for strict definition for it, but it
does have the frame format. And the optical systems which could
regenerate SONET/SDH framing, didn't care about timing, they just
wanted to be able to parse and generate those frames, which they
could, but they could not do it for ethernet frames.

I think it is pretty clear, the driver was to support long haul
regeneration, so it was always going to be a stop-gap solution. Even
though I know some networks, who specifically wanted WAN-PHY for its
error reporting capabilities, I don't think this was majority driver,
majority driver almost certainly was 'thats only thing we can put on
this circuit'.

-- 
  ++ytti