Network Isolation

[pl_svn]

Alex... what about those inside devices (eg. Mac mini or NAS) that come with gigabit ethernet? :-/

[jabbr]

Larry and Jonathan: Thanks very much for the explanation regarding the reasoning behind your choice to use SFPs and LC-LC cables.

 

When I catch my breath after June's big shipping frenzy (REGEN "ambers" are being boxed now!), I am going to order a pair or two of the TP-Link FMCs. I plan to compare the 100MB models to the Gigabit ones. John Swenson has dug into some Ethernet PHYs recently and found that the Gigabit ones are vastly more complex and generate a lot of ultra-higf frequency noise and spikes. Obviously does not matter for the normal data applications, but it might for us audio crazies.

 

Ciao,

ALEX

 

Well it turns out that noise is very important for data applications as well as audio and there is a surprising amount of work that has been done regarding noise and jitter in the ultra high speed ethernet domain e.g. 10gbe, 40gbe and 100gbe. This is where optical ethernet really pulls away from copper. As the network speed goes up, and as the cable length goes up, the copper ethernet power requirements go way way up, but not so much for optical. So for example, a 10 or 100mbs copper ethernet chip requires much less power than 1 gbs ethernet and much much less than 10 gbe, but actually the 40gbe Intel card (x710 series) requires 1/2 the power of the x520 series! These cards require just a few watts regardless. Power supply noise is clearly a factor however.

 

I think that regardless of the fact that a 100mb ethernet connection is being made, at the computer is a 1 gbe chip. Copper ethernet is known to be noisier than optical particularly for long connections, and particularly if "green ethernet" is not being used. What we may be seeing is that in the case of the FMC is acting in a similar fashion to the regen, that is capturing a copper ethernet signal which may have become degraded by a long cable, and then regenerating an optical signal, which is then reconverted back into electrical ethernet (but now reconstituted).

 

The short ethernet patch cord provides a much cleaner ethernet signal to the destination PHYS. Even better is eliminating the electrical ethernet signal with an optical ethernet NIC and switch. At least for the E5 Xeon series and with Intel NICs, the bits flow directly into the processor cache. I don't think there is one single answer that applies to all situations.

[tranz]

Thanks for all the ideas and it looks like I will have to try this too. I have noticed that wired sounds better than wireless in the streamer world, and the most logical answer is that the streamer receiver chip has to work harder in (re-)requesting data packets which in turn means more electrical noise. Similar in concept to the USB Regen. So providing the streamer (or Network DAC) with the data in away that allows it to not have to work hard helps.

 

It also makes sense why the NADAC requires a very specific network setup.

 

Cheers

[tranz]

Is it not interesting that when the thread was revived 2 years ago, Miska's first suggestion was optical ethernet!! The man was right, again...

 

Time for a no holds barred, money no object, CAPS update from Chris...

[tranz]

Thanks jabbr and Ted, I think I am getting it.

 

So, as I see, if I go to fiber switch, then I only need one FMC to connect a component (still need SFP's on both ends per jabbr and Ted). To me that is a plus, fewer pieces of equipment, less clutter, one less LPS may be. So I think I am going to take the fiber switch route. I have to see which one out of the three mentioned in posts above. If TP Link has a fan, that's probably not good. These fans can be very noisy. So there is the Diablo and a Netgear I think.

 

Shopping List (to connect HTPC, NAA, and NAS):

 

- 1 Fiber Switch.

- 2 FMC's TP MC220L (one to NAS, one to NAA).

- 5 SFP's (Cisco GLC-SX-MM SFP 1000-baseSX, as mentioned by jabbr few posts back).

- 1 fiber network card for HTPC, jabbr had mentioned Mellanox ConnectX-2 on ebay.

- 3-LC-LC multi-mode fiber cables.

 

Please let me know if I missed anything. Thanks.

 

Would it not be better to use single mode cables?

[sig8]

Would it not be better to use single mode cables?

 

It is my understanding based on post #496 by jabbr here and few others that all Optical Switches use Multi Mode SFP's and I think all SFP's are multi mode as well, that is if you want to go to a fiber switch route, which I think I would; then you should/need to stick to multi-mode.

 

If you just want to do EuroDriver's 2-FMC solution under post number 151, then you can use single or multi-mode.

 

Choose one and stick with it. Multi-mode for two way traffic, single mode for long distances; this is what my basic understanding is.

[ted_b]

So for example, a 10 or 100mbs copper ethernet chip requires much less power than 1 gbs ethernet and much much less than 10 gbe, but actually the 40gbe Intel card (x710 series) requires 1/2 the power of the x520 series! These cards require just a few watts regardless. Power supply noise is clearly a factor however.

 

 

So, as I posted on your results thread, my first foray into fiber is a great success. Next is my NAS, followed closely by installing a fiber NIC card (to go direct to my i7 instead of the FMC and a copper umbilical). However, these NIC cards do not show a separate power option; i.e they get their power from the noisy pc environment. Am I robbing Peter to pay Paul here?

[jabbr]

So, as I posted on your results thread, my first foray into fiber is a great success. Next is my NAS, followed closely by installing a fiber NIC card (to go direct to my i7 instead of the FMC and a copper umbilical). However, these NIC cards do not show a separate power option; i.e they get their power from the noisy pc environment. Am I robbing Peter to pay Paul here?

 

I've considered that, and don't think so because the optical connection should be lower noise than the Ethernet connection regardless.

 

Its probably more important to go with the lowest noise solution closest to the DAC connection.

 

You could go with a LPS ATX power supply, or LPS 9V on the DN2800MT board ... now there is a single PCI-e slot and the question becomes whether it should be used for the USB card, or Ethernet card ... probably USB (its closer to the DAC). There might be a better board for NAA that has 2 PCI-e slots ... but still has low power (hard to beat the DN2800MT ...). I'm also going to test the DN2800MT with no local disk at all (network boot).

 

Time of experimentation.

[jabbr]

It is my understanding based on post #496 by jabbr here and few others that all Optical Switches use Multi Mode SFP's and I think all SFP's are multi mode as well, that is if you want to go to a fiber switch route, which I think I would; then you should/need to stick to multi-mode.

 

If you just want to do EuroDriver's 2-FMC solution under post number 151, then you can use single or multi-mode.

 

Choose one and stick with it. Multi-mode for two way traffic, single mode for long distances; this is what my basic understanding is.

 

No, you can certainly use single mode with fiber switches!. SFP allows you to choose between single mode and multi mode ... you should be sure to use the single mode SFPs at each end of the fiber. You can swap cables and SFPs to try each out.

 

Single mode optics (SFP) tend to be more expensive and are not as widely available. Whether one is better than the other is complicated. Certainly at long distances singlemode/LR is best. For short distances other factors including quality of the SFP modules, quality of the cables, power supplies etc. may make much more of a difference.

 

Think of it sort of like the USB Regen: when using a very short USB-USB connector, the quality of the connector is not so important and is better than a USB cable. In any case once I get my system up and running, for the final connection between switch and NAA I'd try single mode.

 

You can search for 1gbs SFP modules: single mode: 1000base-LX and 10Gbase-LR, multi mode: 1000base-SX, 10Gbase-SR

[tranz]

It is my understanding based on post #496 by jabbr here and few others that all Optical Switches use Multi Mode SFP's and I think all SFP's are multi mode as well, that is if you want to go to a fiber switch route, which I think I would; then you should/need to stick to multi-mode.

 

If you just want to do EuroDriver's 2-FMC solution under post number 151, then you can use single or multi-mode.

 

Choose one and stick with it. Multi-mode for two way traffic, single mode for long distances; this is what my basic understanding is.

 

Thanks signature 8.

 

I was looking at this, but I guess for the distances we are using it for it really does not matter. Except for the reason you mentioned.

 

http://www.multicominc.com/training/technical-resources/single-mode-vs-multi-mode-fiber-optic-cable/

 

Thanks jabbr for the update.

[pl_svn]

Single mode optics (SFP) tend to be more expensive and are not as widely available. Whether one is better than the other is complicated. Certainly at long distances singlemode/LR is best. For short distances other factors including quality of the SFP modules, quality of the cables, power supplies etc. may make much more of a difference.

 

I also argued, from a post here, that SC connectors (and single mode fiber cables) are "bulkier" than LC and multi mode

never seen both kinds one beside the other so... not sure I got it right

[ted_b]

I've considered that, and don't think so because the optical connection should be lower noise than the Ethernet connection regardless.

 

Its probably more important to go with the lowest noise solution closest to the DAC connection.

 

You could go with a LPS ATX power supply, or LPS 9V on the DN2800MT board ... now there is a single PCI-e slot and the question becomes whether it should be used for the USB card, or Ethernet card ... probably USB (its closer to the DAC). There might be a better board for NAA that has 2 PCI-e slots ... but still has low power (hard to beat the DN2800MT ...). I'm also going to test the DN2800MT with no local disk at all (network boot).

 

Time of experimentation.

 

Yeah, tradeoffs. And in my case, I haven't even tested an NAA yet. My JCAT card is still in my i7 (single pc mode right now). So, my tradeoff issues are about NAA v single pc, then if I configure an NAA on my DN2800MT I use the ONE PCie slot for my JCAT card (assuming that use of the PCIe slot is better than putting a fiber NIC there and simply using a mobo USB with Regen). There are mini-PCI (horizontal) spots on the mobo but I don;t know of any fiber NIC card that can go there. And with a NAA architecture, does the audiopc (HQPlayer desktop) benefit as much from fiber as the NAA? Argh!

 

Another tradeoff issue I'm dealing with is the cheap used SFP switches on ebay (under $80) that all use an internal power supply vs. a $259 Diablo that can accept a linear or battery 5V/2A. And is the noise in these switches more or less if they are capable of higher speeds than gigabit (speeds audio doesn't need).

[Superdad]

I've been enjoying this discussion even though I've yet to order any optical network toys (I'll get there). And great posts Jabbr.

 

So, as I posted on your results thread, my first foray into fiber is a great success.

 

Which thread is that Ted? Is it this one?: http://www.computeraudiophile.com/f22-networking-networked-audio-and-streaming/optical-network-configurations-24641/

[ted_b]

Yep, Alex that's the one. It's gotten kind of cluttered but Jabbr put it up as a results thread for those of us trying fiber LAN stuff.

[frederick184]

OK, so I'm about to jump in and try out some optical isolation in my system. I've read through most of this thread and I'm wondering what to do for the best. My system comprises a PC running Windows 10 with HQ Player, a Synology NAS for my music files, both connected by ethernet to my router. I then have an ethernet run from the router to my CAPS server running WS2012 with AO which is my HQ Player NAA. From there it connects to my DAC via a USB cable and an Uptone Audio Regen Amber.

 

Rather than purchase two FMC's and some fiber, I figured why not just purchase a fiber switch, some SFP's and be done with it. Here's where I am getting confused. How do I tie all of this together at the fiber switch? I understand that I would simply replace the ethernet run to the NAA PC with fiber and plug it into the fiber switch via an SFP, and at the other end I would use an FMC and a short length of ethernet cable to connect to the NAA PC. I also have a Comcast router which is currently feeding my internal router (which I want to replace), my Windows 10 PC and my NAS. I assume these all just plug into the ethernet ports on the fiber switch? Does any mapping or port setup configuration need to take place on the fiber switch? Never owned one, so at a loss here.

 

Thanks

Colin

[ted_b]

Colin,

Both ends of a fiber run need an SFP which slides into a unit (at the source end that would be a fiber card or an FMC-connected-to-a-short-copper-umbilical; at the switch end that would be another FMC and umbilical, or a true Fiber switch). So having a fiber switch allows you to use the FMCs only at the source end (pc, NAS, etc) unless of course you have an available PCie slot and then you can install a $40-50 Mellanox fiber card in your pc and delete an FMC.

 

Your fiber switch needs to accommodate the copper coming in (rj45), any copper needed for non-fiber connections, and then enough SFP ports for your fiber needs (HQP pc, NAS, NAA,). No real port config needed, I don;t think (I will know more when I get signature8's two switches tomorrow....a TP Link and a Diablo). He compared them and so will I. The Diablo has our interest cuz it has an external ps that can be replaced with a linear or battery solution. Signtaure8 won't tell me his final decision so as not to "lead the witness". Currently I have my HQP pc with a Mellanox fiber card-to-FMC setup, and my NAA with an FMC-to-FMC setup. Either switch will allow me to also attach my NAS (10 meters) and my Rendu (2 meters) to fiber, using two of the FMCs that the new switch will replace.

[frederick184]

Thanks, Ted. I see you guys went for the TP Link MC220L so that explains the use of SFPs at both ends. I planned on buying:

 

Fiber Switch (manufacturer TBD)

2 x MC220L

5 x SFPs

1 x Mellanox ConnectX-2 fiber network card

3 x LC-LC MM fiber cables

 

1 x optical link to PC, NAS and NAA

 

Thanks a lot for your guidance

Colin

[jabbr]

Don't you need 6 SFPs? 3 for switch, 1 for NIC and 2 for FMCs

[ted_b]

Thanks, Ted. I see you guys went for the TP Link MC220L so that explains the use of SFPs at both ends. I planned on buying:

 

Fiber Switch (manufacturer TBD)

2 x MC220L

5 x SFPs

1 x Mellanox ConnectX-2 fiber network card

3 x LC-LC MM fiber cables

 

1 x optical link to PC, NAS and NAA

 

Thanks a lot for your guidance

Colin

 

Yes, I count 6 SFP's. What is the "1 x optical link"?

[frederick184]

Sorry, I mis-typed. I meant 6 SFP's. "1 x optical link" - I meant one optical link each to PC, NAS and NAA. It's Friday, I need to go home :-)

 

Colin

[frederick184]

Ordered everything but the fiber switch. Came to around $200 by buying everything on eBay. Good deal!

 

Colin

[jabbr]

Ordered everything but the fiber switch. Came to around $200 by buying everything on eBay. Good deal!

 

Yes. If you are into LPS, the Diablo is attractive. The TP Link is a better general purpose switch (12 SFP ports with 4 shared copper/SFP ports). I got the TP Link because I got a great deal.

 

It is possible but unknown whether an LPS would affect the audio quality. Likewise different SFP modules might affect audio quality including multimode vs singlemode fiber. My prediction is that simply going optical will make the biggest difference but there certainly is a great deal of room for experimentation.

[Superdad]

I'm still really enjoying this still comprehensible thread. I just wish I had the time to order up some FMCs and goodies to experiment in my own system. In due time for sure.

Hope you all are having a great weekend. Happy Father's Day to those who are one!

 

AJC

[tranz]

The answer is more complicated than it might be, partially because there are so so many products and while they are intended to interoperate, they may not always. Like everything. Generally when we say 1Gbe (gigabit ethernet), we are refering to 1000base-T (gigabit ethernet over twisted pair using RJ-45 connector).

 

A requirement of 1000base-T is autonegotiation with 10base-T and 100base-T devices. Optical gigabit ethernet (1000base-SX) does not have this requirement, but specific switches and SFP modules may implement e.g. 10G/1G SFP+ or 1000/100 base-SX.

 

So.... bottom line is that I would assume that any sensible NAS would do 1Gbe (1000base-T). I looked up the Sonore Rendu and it mentions Ethernet without a specific speed, so in this day and age, I'd assume that it does 1000base-T but you know the saying about "assume making an ass of u and me". In that spirit, I will start a new thread "Optical Network Configurations" where people can post "known good" combinations of ethernet devices, switches, SFP modules so that we can all see what other people have been found to work.

 

 

I ran into something similar a few days back and ended up ordering an 100base TP Link FMC device since the 1000base would not communicate with my streamer directly (2 lights unlit). The streamer is 100base, and so likely the TP gigabit FMC was not seeing all the necessary wires connected. So for those with 100base devices just keep this in mind when ordering an FMC.

 

As soon as I receive them I will confirm.

 

Perhaps this is what Ted_B was seeing running into during an earlier test too?

[tranz]

Yes. If you are into LPS, the Diablo is attractive. The TP Link is a better general purpose switch (12 SFP ports with 4 shared copper/SFP ports). I got the TP Link because I got a great deal.

 

It is possible but unknown whether an LPS would affect the audio quality. Likewise different SFP modules might affect audio quality including multimode vs singlemode fiber. My prediction is that simply going optical will make the biggest difference but there certainly is a great deal of room for experimentation.

 

Do you know whether Diablo switches everything behind the scenes to a copper gigabit switch? I.e. no direct optical to optical. If that is the case you could save some money. Of course the one box, one LPSU form factor is very handy.