Could he bond dwm multiples at lower rates? Chuck McCown McCown Technology Corporation 8401 N Commerce Dr Lake Point, Utah 84074 801-250-9503 435-830-4306 cell www.mccowntech.com www.microtrench-blades.com www.terabitnetworks.com
From: Trey Scarborough Sent: Thursday, January 25, 2024 5:00 PM To: af@af.afmug.com Subject: Re: [AFMUG] optical TX power levels Ive done a lot of these 100G 80k links and its not likely dispersion causing your problem. Its more likely the opposite. If you have segments of NZ fiber "Non-zero dispersion-shifted fiber" you can have issues. After looking at your OTDR it looks to be a mix of different fiber types thats how you get the negative loss splices. If it is a mix of NZ and smf28 fiber your probably not going to be able to get it to work. The NZ fiber causes issues with the 1200-1300 signals on those optics. I have had spans of 50k that 80k optics would not work on due to this. I would have them run an OTDR at 1310 and see what it shows you are likely to get a very different looking result. If that's the case there aren't too many good options. Your best is if your switch has 400g ports get some OpenZR 400G optics and use them. Surprisingly that aren't incredibly more expensive than the 100G 80ks. I would have the fiber provider give you a 1310 OTDR and also request fiber type information for the span. We build these things all the time so if you need some help feel free to email me and I can see about finding a solution that will work for you. On 1/24/24 6:40 PM, Zach Underwood wrote: Ok we got the report back from the fiber supplier. This is new to me so anyone can offer insight into it? PDF https://drive.google.com/file/d/1KeIuWHFsiKZHxcmpPiY8PX_-PABl55Sz/view?usp=sharing On Wed, Jan 24, 2024 at 6:00 PM Daniel Pautz via AF <af@af.afmug.com> wrote: Dispersion compensation module - https://www.fs.com/products/65783.html From: AF <af-boun...@af.afmug.com> On Behalf Of Ken Hohhof Sent: Wednesday, January 24, 2024 3:53 PM To: 'AnimalFarm Microwave Users Group' <af@af.afmug.com> Subject: Re: [AFMUG] optical TX power levels I spent a few minutes searching on the term DCM and came up with “chirped fiber Bragg grating”. https://en.wikipedia.org/wiki/Fiber_Bragg_grating OK, I’m out of my depth now. From: AF <af-boun...@af.afmug.com> On Behalf Of Daniel Pautz via AF Sent: Wednesday, January 24, 2024 4:40 PM To: AnimalFarm Microwave Users Group <af@af.afmug.com> Cc: Daniel Pautz <d...@webnx.com> Subject: Re: [AFMUG] optical TX power levels Perhaps pick up a used cheap DCM and see if it helps, adjustable preferred if not as close to the fiber distance. Our newest 100G dwdm build (dozen 100G optics) very much needed a DCM on it. From: AF <af-boun...@af.afmug.com> On Behalf Of Chuck McCown via AF Sent: Wednesday, January 24, 2024 3:36 PM To: 'AnimalFarm Microwave Users Group' <af@af.afmug.com> Cc: ch...@go-mtc.com Subject: Re: [AFMUG] optical TX power levels Gotta think of the Fourier series of the pulse. Yes group velocities or group delay of the whole enchalada. It is all kinda the same thing. They were doing some kind of soliton fiber development. Haven’t heard much for some time about that. No idea how frequency pure/coherent the tx is. I imagine phase coherency is a big deal. From: Ken Hohhof Sent: Wednesday, January 24, 2024 4:12 PM To: 'AnimalFarm Microwave Users Group' Subject: Re: [AFMUG] optical TX power levels Looks like different wavelengths have different group velocities, so compensation is possible (but probably not cheap?). Is this because the transmitter doesn’t generate literally a single wavelength? Or is this a WDM issue? Chuck says the pulses get smeared out in time, that sounds like the first one. From: AF <af-boun...@af.afmug.com> On Behalf Of Chuck McCown via AF Sent: Wednesday, January 24, 2024 3:56 PM To: AnimalFarm Microwave Users Group <af@af.afmug.com> Cc: ch...@go-mtc.com Subject: Re: [AFMUG] optical TX power levels Yeah, the pulses tend to get smeared out in time if there is too much dispersion. Similar to trying to use too high level of QAM with SNR issues. From: Josh Luthman Sent: Wednesday, January 24, 2024 12:26 PM To: AnimalFarm Microwave Users Group Subject: Re: [AFMUG] optical TX power levels Even if the RX level is good? > rx was within 0.3dBm on all 4 lanes on both sides On Wed, Jan 24, 2024 at 1:22 PM Daniel Pautz via AF <af@af.afmug.com> wrote: Yeah makes me think the two paths have different loss. We have had that on mirrored paths, or even single paths with crappy splices on one of the strands. From: AF <af-boun...@af.afmug.com> On Behalf Of Chuck McCown via AF Sent: Wednesday, January 24, 2024 11:12 AM To: AnimalFarm Microwave Users Group <af@af.afmug.com> Cc: ch...@go-mtc.com Subject: Re: [AFMUG] optical TX power levels Did anyone do dispersion testing on the fiber? Chuck McCown McCown Technology Corporation 8401 N Commerce Dr Lake Point, Utah 84074 801-250-9503 435-830-4306 cell www.mccowntech.com www.microtrench-blades.com www.terabitnetworks.com From: Zach Underwood Sent: Wednesday, January 24, 2024 12:07 PM To: AnimalFarm Microwave Users Group Subject: Re: [AFMUG] optical TX power levels tired again this morning and still no link. rx was within 0.3dBm on all 4 lanes on both sides. We got 10gb 80km to link up. This will do for now. We will be looking at getting 40gb 80km single lane optics or adding another site to fiber loop to shorten the footage to under 40km. On Wed, Jan 24, 2024 at 11:14 AM Colin Stanners <cstann...@gmail.com> wrote: So both of those SFPs are within the tx power range. 100G may not work on a link that long unless you have dispersion compensation fiber on the path or in a huge loop in a box style at one end. You likely cannot change tx power levels on those SFPs, they will run at the max they can do for that specific unit. On Wed, Jan 24, 2024, 7:46 a.m. Zach Underwood <zunder1...@gmail.com> wrote: TX Power 2~6.5dBm I am struggling to get this 100gb link up. In the field this link is quoted at 31 miles. The rx levels are -22 and -20 on both sides but I can't get it to link. I take the same optics to the lab and add 20dbm of attenuator to get almost the same rx levels as the field and it will link up. I have added error-correction encoding reed-solomon per the user guide for links over 40km. So far I have not found a way to change the TX levels in arista, the options are in the CLI but they dont seem to change the outcome. For me this is the first time dealing with 80km optics or 100gb optics over 10km. switch is Arista DCS-7060SX2-48YC6-R https://resource.fs.com/mall/doc/20230531114903y4ljxw.pdf https://www.fs.com/products/115818.html?attribute=29032&id=3462585 On Wed, Jan 24, 2024 at 8:35 AM Colin Stanners <cstann...@gmail.com> wrote: There should be. What does their datasheey indicate for tx power range? On Wed, Jan 24, 2024, 7:31 a.m. Zach Underwood <zunder1...@gmail.com> wrote: Yep labels identical but there is a difference in default power levels. On Wed, Jan 24, 2024, 8:13 AM Mike Hammett <af...@ics-il.net> wrote: Oh, meaning the variance between the two, otherwise identical models? ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP ---------------------------------------------------------------- From: "Zach Underwood" <zunder1...@gmail.com> To: "AnimalFarm Microwave Users Group" <af@af.afmug.com> Sent: Tuesday, January 23, 2024 12:51:39 PM Subject: [AFMUG] optical TX power levels I got 2x 100gb 80km optics from FS that run difficult default TX power levels one is 3.81dBm and the other 2.63dBm, the config on the arista devices hosting the optics is the same. Has anyone seen much difference between optic like this? My sample size is small due to the optices costing $4k each -- Zach Underwood (RHCE,RHCSA,RHCT,UACA) My website advance-networking.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- Zach Underwood (RHCE,RHCSA,RHCT,UACA) My website advance-networking.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- Zach Underwood (RHCE,RHCSA,RHCT,UACA) My website advance-networking.com -------------------------------------------------------------------- -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -------------------------------------------------------------------------- -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com ---------------------------------------------------------------------------- -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- Zach Underwood (RHCE,RHCSA,RHCT,UACA) My website advance-networking.com -------------------------------------------------------------------------------- -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
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