Re: 100G, input errors and/or transceiver issues

["Stonebraker, Jack J" <jjs () ots utsystem edu>]

We have a moderately dense deployment of 100-Gig LR4 (Both DWDM Lambdas and Juniper MX) around our WAN and we don't 
clock any background input errors on our interfaces unless there is an ongoing problem.  That said, we have experienced 
issues with sub-millisecond link state changes between two endpoints that are physically cross connected to one another 
with no intermediary Layer 1 (DWDM, Etc.).  There doesn't seem to be rhyme or reason to this and we've looked at each 
lane extensively and so far, everything has been inconclusive.  We also experienced some code issues on Juniper 
MPC3D-NG's running 100-Gig's and our DWDM Client Ports where timing would start to slip and eventually cause the link 
to fail.  Both Juniper and the DWDM Vendor found code variances they patched.  We haven't had any such issues on 
Juniper MPC5's 7's or the 10003 Line Cards.

TL;DR:  In my experience, 100-Gig might require some more TLC then 10-Gig to run clean and is more sensitive to 
variations in transport.  Other's mileage may vary.

Best,
JJ Stonebraker  |  Associate Director
The University of Texas System | Office of Telecommunication Services
(512) 232-0888  | jjs () ots utsystem edu

________________________________
From: NANOG <nanog-bounces+jjs=ots.utsystem.edu () nanog org> on behalf of Graham Johnston <johnston.grahamj () gmail 
com>
Sent: Monday, July 19, 2021 12:19 PM
To: Saku Ytti <saku () ytti fi>
Cc: nanog list <nanog () nanog org>
Subject: Re: 100G, input errors and/or transceiver issues

Saku,

I don't at this point have long term data collection compiled for the issues that we've faced. That said, we have two 
100G transport links that have a regular background level of input errors at ranges that hover between 0.00055 to 
0.00383 PPS on one link, and none to 0.00135 PPS (that jumped to 0.03943 PPS over the weekend). The range is often 
directionally associated rather than variable behavior of a single direction. The data comes from the last 24 hours, 
the two referenced links are operated by different providers on very different paths (opposite directions). Over 
shorter distances, we've definitely seen input errors that have affected PNI connections within a datacenter as well. 
In the case of the last PNI issue, the other party swapped their transceiver, we didn't even physically touch our side; 
I note this only to express that I don't think this is just a case of the transceivers that we are sourcing.

Comparatively, other than clear transport system issues, I don't recall this sort of thing at all with 10G "wavelength" 
transport that we had purchased for years prior. I put wavelengths in quotes there knowing that it may have been a 
while since our transport was a literal wavelength as compared to being muxed into a 100G+ wavelength.

On Mon, 19 Jul 2021 at 12:01, Saku Ytti <saku () ytti fi<mailto:saku () ytti fi>> wrote:
On Mon, 19 Jul 2021 at 19:47, Graham Johnston
<johnston.grahamj () gmail com<mailto:johnston.grahamj () gmail com>> wrote:

Hey Graham,

> How commonly do other operators experience input errors with 100G interfaces?
> How often do you find that you have to change a transceiver out? Either for errors or another reason.
> Do we collectively expect this to improve as 100G becomes more common and production volumes increase in the future?

New rule. Share your own data before asking others to share theirs.

IN DC, SP markets 100GE has dominated the market for several years
now, so it rings odd to many at 'more common'. 112G SERDES is shipping
on the electric side, and there is nowhere more mature to go from
100GE POV. The optical side, QSFP112, is really the only thing left to
cost optimise 100GE.
We've had our share of MSA ambiguity issues with 100GE, but today
100GE looks mature to our eyes in failure rates and compatibility. 1GE
is really hard to support and 10GE is becoming problematic, in terms
of hardware procurement.


--
  ++ytti