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Optical Network Configurations


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On 2/16/2019 at 1:06 PM, Superdad said:

 

$1,000 SFP modules? Yikes!

So then what is your opinion of the Foxconn or Finisar modules that can be had from DigiKey for $22-32?

 

Yikes indeed. I just setup two Catalyst 9300's and the entire cabling bill came to $675.

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  • 6 months later...
1 hour ago, jabbr said:

24 ports 10Gbe SFP+ and 2 ports 40 Gbe QSFP $495!!

https://www.servethehome.com/mikrotik-crs326-24s2qrm-review-insane-switch/

 

That's crazy. I wonder what ISL and LAG technologies it supports. Gonna take a look. FS.com 10GBe LC MM  transceivers are ~$17.

 

Took a quick look at their product lineup and the CRS317-1g-16S+RM is $349. 16 port SFP+.

 

Important: Passive Cooling.

 

 

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35 minutes ago, jaaptina said:

I'm going to buy the Sonore opticalModule to use down stream just in front of my network player. Upstream I have TP-Link MC220L or Trendnet TEG S51SFP. What would you recommend? Or should I sell both and buy some Cisco SFP switch? 

 

If your streamer is only Copper RJE plus wireless I don't see the point in going copper<>optical<>copper. The media converter is going to have it's own power supply. You are trading deck chairs on the Titanic in this regard.

 

You are better off going copper from the get go and let distance attenuation do the job for you. No sense in putting a power supply as close to the streamer input as possible.


Better yet use the WiFi.

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33 minutes ago, barrows said:

While I do not agree with Gordon Rankin on everything, I d.o agree with his position on WiFi.  In any case this podcast is a good listen:

 

https://www.audiostream.com/content/gordon-rankin-wavelength-audio-audiostream-podcast-no12

 

At Sonore we do not really recommend WiFi for those looking for best sonic performance.

 

All you or Gordon would have to do is listen to some music while Airplane mode is enabled/disabled and pick it out.

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54 minutes ago, barrows said:

And there are things I disagree on with him as well...  But it would be a boring world with nothing to learn if everyone, even EEs, all agreed!

 

 

At 31 minutes. Wow, just WOW. He's clueless. I don't know how one even begins to make the claim he just made. It's nonsensical.

 

He's maintaining that WiFi takes 40 times the amount of data to do the same thing as Wired. He's talking about WiFi that for $100 can deliver easily 50 concurrent 24/192 streams.

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  • 1 month later...
36 minutes ago, ericuco said:

 

Yes, I have a TP-Link MC220L FMC between the Google Wifi & Mikrotik. I tried the FMC in both Auto and Force mode but neither would connect.

 

On the Mikrotik, all four SFP ports are used - 1) music server w/ Intel X520-DA1 NIC, 2) opticalRendu, 3) Google Wifi/FMC & 4) another optical switch for Roku connection. The only connection that does NOT connect (judging by the lights on the Mikrotik) is the Google Wifi/FMC when using SwOS. There are no problems with the default RouterOS.

 

I am not in configuring a managed switch. Much more of an unmanaged switch person so either it works or it doesn't for the most part. I might revisit this later but not just enjoying the music.

 

Have you tried flipping the fiber connector Tx/Rx at one end? Just remove the tab.

 

 

LCLC TX RX swap.jpg

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10 hours ago, hpfish said:

I connect my TPlink FCM to my EtherRegen using single mode SFPs and fiber cable and it works fine, but wonder if I should use multi-mode instead of single mode.  Which method is preferable?   Any ideas why one prefers one over the other?  

 

Single mode is 1350nm, MM is 850nm. Single mode is for long haul (distances greater than MM 980 feet). Single mode tranceivers will, comparatively, drive your impelementation costs up.

 

There's zero reason to go with Single Mode. Since these are data devices and not audio devices neither makes an audible difference.

 

 

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On 4/16/2020 at 11:37 AM, jabbr said:

Laying cable is work! QSFP28 with Source Photonics 100Gbase-LR4 end to end from Mellanox SN2700 running Sonic to Dell Precision 5820 W-2245 Workstation

 

Is there a reason your running LR optics in a home vs the cost savings of SR?

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2 minutes ago, jabbr said:

 

Let's see ... 0S2 100m 3.0mm from fs.com is $30 including shipping from China...

 

I picked up 100Gbase-LR4 modules for $100/each ...

 

Alternatively 100Gbase-PSM4 or 100Gbase-SR4 modules for $50 and run MSO  cables ...

 

So no real cost savings anymore ... particularly PSM4 vs SR4 and this way I can run 1/10/25/40/100Gbe over same cable ...

 

I've been seeing new QSFP28 LR for ~$400 and new SR for $100. There isn't a price premium in cabling like there used to be.

 

Are you purchasing used transceivers?

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6 minutes ago, jabbr said:

 

Yeah ebay ... you can even get "new" PSM4 or SR4 modules easily at $50 ... I just jumped on the LR4s because of the price but there are many ways that work -- as well as those awesome fiberoptic cables with QSFP28's at each end (Mellanox and others). I got a few for $100 each! I mean ha ha there is zero need to do this but I've been stir crazy ... 

 

I'm halfway through my ACEP (Aruba Certified Edge Professional). It's HPE's equivalent of my CCNP Route/Switch. Bonus is that my employer is paying out bounties because they need this for partner status. It's 6 tests though. Bit of a slog but most of the material is review to my CCNP.

 

I'm good with 10G at home. I get to do plenty of 10/25/40/80/100 at work. I don't even know what I'm going to do with 10G but for $210 in pieces parts why not 😉

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5 minutes ago, jabbr said:

Getting the firmware updated on my 'old' SN2700 (circa 2016) required black magic and then loading SONiC has been another experience, but thank god for open source! I can't even imagine what I'd do with the layer 3 capabilities -- and no idea how to use them! Your field is advancing at an astonishing rate!

 

It's crazy. My goal is to turn myself into a NAC and Firewall unicorn. So it's going to be Cisco ISE, HPE Aruba Clear Pass and Fortigate. Couple that with deep dive into Python and that's where I'm going to specialize.

 

We are at the point that there can't be any generalist any longer like 20 years ago.

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1 hour ago, John769 said:

Hi. Out of interest, what advantage would it have over a microtik crs305?  Cost wise, here in the EU, a s/h cisco might be about the same (ish) as new Microtik.

 

Any crs305 users care to offer more feedback on it versus other fmc's or switches?  One minor observation from the reviews is that it appears to run quite hot, which could be disinsentive in summer if you live in a hot place.  

 

1: 48 1GBe copper ports

2: 4 SFP+ 10GBe ports. Looks like the crs305 is SFP (1GBe).

3: In the states I can get them for $50-$60 shipped. You'll have to check ebay listings in your neck of the woods.

4. It's Cisco

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  • 1 month later...
On 6/9/2020 at 2:36 AM, tgb said:

But SFPs sounds different too !? what a weird hobby we have...in fact, "weird" is not the proper word, "difficult" is more appropriate

 

I like to look at it from a critical thinking perspective. 

 

Fully realized 10G can ship 2 CD's worth of audio every second. My system can cue up a 16/44.1 track in about 300ms and then not use the connection any longer.

 

You are playing out of buffer, not off the wire. As a matter of fact, on well engineered systems, you can start playback and pull the plug. 

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Just now, The Computer Audiophile said:

If I had to guess, I'd say their comments have nothing to do with the speed of the interface. Just a guess. 

 

In a well engineered system, the faster the wire speed, the less the wire is used the less the transceiver is used. Hence talking about MM OM3/OM4/OM4/MPO 12 strand/LC BiDi or SM fiber or transceivers. 10/QFSP+/QFSP28/40/80/100G. 

 

One HAS to accept that we aren't playing off the wire. We are playing out of buffer. The quicker you can fill the buffer (regardless of size) the less the wire is of any issue. If I can get 5000MB/s wire rate (QFSP+) my wire time for a 75MB track is .015 of a second. It's also my tranceiver time. 

 

The only other argument that can be made is that somehow having a SM vs MM tranceiver installed, but playing back from local disk would still be affected, is one that could be effectively made. I'm all ears on that one. 

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7 minutes ago, ray-dude said:

The correlation I have seen for SFPs seems to be more related to power consumption of the module.  I suspect the mechanism is some induced noise from the transceiver.  Generally speaking, the lower the power consumption, the better the sound.

 

Power is consumed when the connection is in use. The faster the connection the less power is used. 

 

Also if we are talking power then you have an inherent problem with the SM vs MM position. 

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27 minutes ago, The Computer Audiophile said:

I hear you 100%. But, the faster the interface the less TIME it is used. I don’t know if faster interfaces have more noise due to higher speeds. No clue. 

 

Faster interfaces typically have a clock that as speed increases clock increases away from our hearing threshold. 

 

Using my QSFP example: If we are only making 'noise' for 0.015 of a second for say a 9 minute track. That interval might as well zero.

 

The bottom line is that network connections are only using power when there is traffic flowing. These are all greened up from a power conservation standpoint. 

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24 minutes ago, ray-dude said:

 

If the root cause is induced noise to power/ground plane, things are more insidious.  A faster interface would have faster switching components, which could be generating a different noise profile.  Depending on the sensitivity of the rest of the system, moving the noise could help or it could hurt SQ.  Other than the truism that less noise is better, noise related SQ impact is devilishly difficult to rationalize or connect the dots on (so system/environment dependent).

 

With optical configurations there is no ground plane. It's optical. Faster is measured in Hz. The faster the higher the Hz the farther away from human hearing. 

 

Agreed the less noise the better: Faster connections spend less time making noise. 

 

I have a dual SFP+ Solar Flare NIC that I can 1 or 10G connections into. One link could be SM and the other MM. I'm keen on anyone being able to pick which is which even if I dialed back the buffering to 10 seconds. 

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14 minutes ago, ray-dude said:

I have not tested an MM transceivers yet.  Have you seen spec sheets where they are less than 500mW consumption? (best I've seen/heard for SM).  Alas, we're still in the empirical stages for these transceivers...try them and see if they sound better, then look at specs and try to figure out why things may be different.

 

MM tranceivers have less Tx power than SM. SM is for long haul 10/40/80Km runs. At 40/80Km Optics I would have to use attenuators if going simply cross rack because the modules would burn out. 

 

Use MM for home environments. The spec is 980 feet. 

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Just now, The Computer Audiophile said:

I’d say they are only using more power when traffic is flowing. If there was no power use the switch would warn me that the device has dropped off the network. It may be a trickle compared to full blast at all times, but it has to be something. 

 

Fair enough. What happens is the certain portions of the PHY will power down. Think of it like Magic Packet/WoL. 

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