Optical Network Configurations

[R1200CL]

12 hours ago, Superdad said:

It's crazy but the bill-of-materials for the state-of-the-art power regulation in the EtherREGEN could come close to equalling the total cost for the Ethernet switches, magnetics, PHYs, clock synthesizers, XO, digital isolators, and high-speed low-jitter differential flip-flops!

 

I suspect this power design will benefit from other upcomming products from John ?

 

Maybe even be used in a possible upgrade of existing products.

 

If you like to go even more crazy, you can cover the radiating parts with mu-metal ?

That part will easily add between $100 and $200 itself to the BOM, not to mention the possible need for a larger case, with additinal cost of pakking and freight. 

 

Alex, do you see that some of your products in the future will move away from SMPS, and iclude AC as power input ?

 

Wouldn’t such an approach be the best technical solution?

But maybe the cost will be to high or ?

[R1200CL]

@Superdad

https://www.fs.com/products/29892.html

(From @bobfa list in his thread)

 

Will this be OK (technically) to use with items John has designed ?

 

Why would I purchase 6 times more expensive SFP modules or use multimode ?

[R1200CL]

1 hour ago, Em2016 said:

1. ultraRendu alone

2. ultraRendu + opticalModule

3. ultraRendu + etherRegen

 

Using your LPS-1.2 to power everything.

And please add the opticalRendu 😀

(Which works fine with the LPS-1.2, as long no, or below 100mA Vbus power drawn from the opticalRendu).

[R1200CL]

2 hours ago, vortecjr said:

However, right now I can measure differences with a wide range of power supplies.

Is this something you can make public ?

 

Like between the following ones:

iFi SMPS

SGC PS

Sonore Ultra PS

LPS-1.2 both at 7 and 9 V

 

Any other top specified PS like the JS-2 and Paul Hynes ones. 
And maybe add the PS used in the Signature Rendu SE version. 

[R1200CL]

10 hours ago, vortecjr said:

These power supplies are different and each has a value / price point. I have consistently said and will continue to say just use the best power supply you can afford. 

So can you share what to expect from a parallel setup of two LPS-1.2 using @[email protected] boxes ?

 

Will use of his boxes degrade the excellent SQ the UltraCaps is so well known for, or is this a setup you can’t endorse as well ?

 

[R1200CL]

1 hour ago, barrows said:

It is usually better for independent third parties to evaluate components, rather than for manufacturers to try and "prove" performance.  

I think it would be cool though, if an independent third party (reviewer) tested various Renderer's for both eye pattern on the USB data lines, and noise on the USB power lines under the same test conditions and published the results.  

I like this idea.

What would it cost pr. test ?

 

And should we add some DAC’s as well and the In the measurement chain ?

 

I’m asking what would be a fair setup ?

Including power supplies. 

[R1200CL]

4 hours ago, robi20064 said:

Do you have any suggestion for an SFP+ capable router with 4-8 standard RJ45 gigabit ports and at least 2 SFP+ ports? A fanless design would be icing on the cake, however I'm not expecting a small footprint for such a device.

You can build your own fan less router that’s probably better than most and adding ipfire SW. 

https://www.iwill.no/en/iwill-ecolan-celeron-bay-trail-d-2-x-lan-2-x-sfp

This give you the options to use dedicated network for audio as well. 
You will still need a switch, as I think Linux firewall SW only support one interface out pr IP address. 
 

It’s very easy to setup. Download SW, and boot from USB stick, and install.

 

You can experiment with various mini pc and add required NIC’s as well as an alternative to readymade firewalls. 

 

[R1200CL]

On 7/10/2020 at 5:55 PM, charlesphoto said:

Finisair FTLF1324P2BTV-B1

These use Fabry-Perot Laser

@jabbr

Can I mix Fabry-Perot Laser with DFB laser ?

 

I will start testing out single mode. (Not sure if a 10GB switch will outperform my etherRegen).

However I like to purchase fiber items that will work with 1GB SFP+/SFP28. 

I suppose this cable is OK in any case ?

On 7/18/2020 at 11:25 AM, StreamFidelity said:

cheap and good FS LC UPC to LC UPC Duplex OS2 Single Mode PVC (OFNR) 2.0mm Fiber Optic Patch Cable

 

[R1200CL]

6 hours ago, jabbr said:

SFP/SFP+/SFP28/QSFP28 modules

Leave out QSFP28. That’s another type of modules. 
 

SFP+ and SFP28 can go in same slot

SPF+ should not be inserted into SFP

SPF can be inserted into SFP+

 

I would chose any of these SFP
FTLF1424P2xCR
FTLF1424P2xCD 

FTLF1424P2xTR
FTLF1424P2xTD 

FTLF1424P2xCL
FTLF1424P2xCV

I’m not sure what last 2 letters indicates. 
 

I’m interested in finding out if any of Finisar modules is using CDR. As that may reduce jitter. 

[R1200CL]

7 hours ago, jabbr said:

My understanding is that with SFP(+) the clock data recovery is after the module. In the XFP module you showed, its on the module and you can see how much larger the modules are.

My understanding is the opposite. 

This is an old article. 
 

Here is an example of a data sheet that shows this technology implemented at a SFP+ Module. 

https://www.finisar.com/sites/default/files/downloads/ftlx1472m3bnl_10gbs_10km_single_mode_multi-rate_sfp-plus_transceiver_product_specifications_rev_b1.pdf

 

I think SFP don’t have this technology implemented. Only SPF+ and above. 

 

I’m now after a lot of reading on the net, convinced that single mode (1310nm) DBF laser is the best solution. 

 

Still, there is a lot more to explore.

Like why don’t this page match with the chart. (Maybe old models). 
https://optical.communications.ii-vi.com/optical-transceivers

 

Here is some basic videos about connectors and colors. 

 

So if you want the best, go green 😀

 

 

 

[R1200CL]

Just bought 5 of FTLF1421P1BCL at $45 including freight on eBay.
 

I like to exchange my multimode ones. I don’t have much expectations in SQ. But like to test.  Multiple cables well below $25 from China including freight. 

 

I have no idea of meaning version B that’s shows Narrow Extraction Bail vs Wide type. 

 

 

[R1200CL]

Some info about CDR. 

 

Beginners Guide To Clock Data Recovery
 

http://thenetworksherpa.com/hardware-clock-data-recovery/

 

I don’t know if CDR implementation in SPF’s is the answer, but it seems to serve a purpose that probably should benefit us. 

[R1200CL]

For those looking for very good and reasonable SFP’s. 

 

https://www.ebay.co.uk/itm/Finisar-FTLF1421P1BCL-OC-48-STM16-GigaBit-Ethernet-1x-2x-FC-IR-1310nm-SFP/114327996056?hash=item1a9e7ac698:g:PMQAAOSwNNxfIUh7

You will have to email him for shipping quote. The modules is new. 
 

I have studied the various available SPF’s from Finisar.

FTLF1421P1xTL (FTLF1421P1BTL) and the FTLF1421P1xCL (FTLF1421P1BCL)is ones that is listed as available today. Data sheet from 2015. 
 

The only difference I have spotted between those two version is a slightly better operation temperature specification on TL version and some different number is a parameter called LOS De-Assert / LOS Assert. I can’t think it matters for our use. 

 

The 1424 options has data sheets from 2005 and EOL, and hence not listed in Finisar website.

  

 

[R1200CL]

@jabbr

 

Have you heard about a White Rabbit Switch?

I wanted to start a tread about if part of that project could be used in design of audio transfers using optical fiber. But I’m not sure how interesting it is. Maybe to technical and advanced?
 

We definitely shouldn’t need a central atomic clock, but maybe some technology that the White Rabbit Project is implementing in switches can be adopted. I guess the only person that could answer that is John Swenson. 
 

There is a lot of information searching the net about this. 
They was also the ones recommended 1310nm and single mode fiber. They also liked APC instead of UPC. Actually they liked to use different wavelength on TR and RX. I leave up to people to search information. If we end up in to much rabbit talk😉, we should probably start a new tread. 
 

1 hour ago, jabbr said:

But honestly the great thing about the specification for 10Gbe+ is that as long as its compliant the manufacturer is asserting that it has done the stressed eye pattern test (not just a simple eye pattern) and that the equipment does not pass along jitter from upstream.

Well, I’m not 100 % sure it’s that simple. Why did John then design the etherRegen and opticalRendu without implementation of SFP+/SFP28. He must have good reasons not to do I hope.  And why is CERN developing almost jitter free switches? (Why aren’t they endorsing 400GB ?). 

Did Sonore and Uptone more or less hide your simple solution from us ?

And why can’t I find any information that buffers will remove jitter outside switches. If it really was that simple, why isn’t there a huge (switching) buffer in the opticalRendu as an example. Not sure how well that would work with RAAT or NAA. 
 

I’ve studied some Finisar data sheets lately. (Only SFP). They have various jitter information. And some even refer to a standard. I have emailed Finisar asking what SFP have the lowest jitter. Probably won’t get an answer. 
I’m also wondering why there is produced fiber that’s have very low transfer rates ? Less power ?

The ones I have suggested (1421) seems to have very low jitter. Still there will be new jitter other places down in the signal processing. 
 

If you are able to explain what we should be looking for in SFP data sheets, that may be helpful.

 

BTW, is it any point producing stressed eye pattern if we’re in 1GB or below. Has anyone done, or why isn’t normal to do ? 

 

We can hope for audio manufacturers to adopt 10GB requirements. I think it may take some time. Unless Uptone and Sonore starts, and everyone keeps on coping them again. 

Maybe someone with god relation to SOtM can ask them to move to 10GB optical interface? If they’re reluctant, why ....

 

[R1200CL]

4 hours ago, jabbr said:

 

Its not huge in terms of fiber terms, obviously fiber encircles the globe, rather:https://home.cern/science/accelerators/large-hadron-collider https://home.cern/resources/faqs/facts-and-figures-about-lhc what makes it "very large" is in terms of a scientific experiment which requires high precision. You might imagine that they have timing needs which go beyond home audio stereo synchronization  

Well, they didn’t go for 10GB or above in the White Rabbit project 😀

 

Remember my point was if any of that technology used in their switches, could be adopted in “audio switches”.
Not the time synchronization in long distances, which I think those guys are after.

 

(Well unless we’re starting our DAC to synchronize with Tidal, Qobuz etc. Wow, Roon in cloud with atom clocks syncing to your DAC 🤓).

 

Actually important in 5G network. Look at Cisco solutions if someone like to study more.

 

So far no one did brother to comment on different jitter specs in SFP data sheets. I don’t have the skills to interpret everything those sheets says. But, 0,0007 compared to 23 seems to make a huge difference. So I was hoping you or @plisskencould enlighten us. If you guys don’t know either, maybe you know who to contact. 
 

And why did they (WR) even bother to develop switches in 1GB, if 10 GB and above should be sufficient when it comes to jitter. 
I would expect these guys know what they’re talking about. 
 

Also the standard mentioned is more than 600 pages, meant to cover everything. Those who “hide” behind that or other standard. Come and show me how that standard demands no jitter. When I scanned through those 600 pages, I didn’t see any eye pattern. I find manufacturers with expensive equipment showing off pictures so measurements can be made. 
 

Again why isn’t there eye pattern available for SPF modules and switches. They do go up to almost 5GB. 

 

And if you study the Finsair selection chart, there is only one module (FTLX1471D3BCV which they won’t tell jitter. Only comply with a spec from 2005), that will comply with optical Ethernet. Rest will only work with 10GB as I understand it. 
So unless you’re building 10GB all over, you will probably struggle, unless you’re using a PC as endpoint. (No other device will comply). 

Also, I’m still not sure it the jitter reduction is related to switch vs module or a combination. 
Does the switches display jitter info in data sheets ?

 

EDIT:

The 10 Gigabit Ethernet (10GbE) specifications are defined in clauses 44 through 54 of the IEEE 802.3-2005 standard. It contains critical timing specifications governing electrical implementations such as 10GBASE-X4 as well as optical interfaces such as the 10GBASE-R. Although the standard specifies jitter limits for the transmitter and the receivers, it does not impose explicit restrictions on the interface reference clock.

 

 

[R1200CL]

Thanks @jabbr

 

From the first link, I noticed requirement is less than 0.25 UI peak-peak of jitter.

It also only applies to the SFP as I understand it. (Not the switch). 

 

It was helpful to find that number. 

IEEE 802.3-2005 standard:

https://d2cpnw0u24fjm4.cloudfront.net/wp-content/uploads/802.3-2005_section1.pdf

When it comes to require a stressed eye pattern test for the etherRegen, I think that will never happen, and it isn’t relevant. 

I’m even not sure if Alex and John moves up to 10GB, you will have such a test. 
Actually the opticalRendu is a switch inside, so your demand should include that device as well. 
 

However, if I’m right that most of the test and engineering done is much related to the SFP’s itself, I do agree very much that moving up to SFP+ and 10GB specifications ought to be done in future releases of streaming devices related to audio. 
I’m not sure if the audiophile market is ready for that step yet. 
With the price of that Mikrotik switch, it also may be challenging to upgrade the etherRegen to a 10GB version. (Which hasn’t been requested either, and probably is unnecessary).

 

By using the “correct” SFP’s in Lumin or opticalRendu, I’m also not sure how much better SQ can be achieved to upgrade to 10GB SPF+. 

So maybe we could discuss if the use of “correct” SFP modules is enough as of today. And moving up further won’t help us at all. 

 

[R1200CL]

3 hours ago, plissken said:

What huge difference to you? To your audio?

Very good question. 
At least I can be confident the SFP is within limitations with a good margin. 

 

What makes this a bit confusing is other modules from Finisar use different parameters. 

 

To my audio, probably not much. But at least I hope I will have a jitter free transfer 😀

However people do report differences in SFP’s, so that’s why I found best possible SFP and have just purchased them. So I will know in two to four weeks. 

Not everyone can control buffers and do things your way. 
 

BTW: I think your famous $8000 test, has nothing to do with testing switches and their jitter. 
But I can see you have a good point. Which also raises some questions about how streamers and endpoint ought to be designed. 
 

Here is an interesting link about White Rabbit switches and phase noise, jitter. 
https://afi-project.jinr.ru/attachments/download/119/mgr.pdf

 

 

 

[R1200CL]

.......well, I guess pulling the network plug should give an indication 😀

[R1200CL]

7 hours ago, jabbr said:

This is *everything* in the link — end to end. That’s the point. When you plug it all together, it has to work. The clock, the board layout, the power supplies, the SFP module. Switch, NIC whatever — all the jitters of everything added up have to be under the limit. If upstream jitter (the stress) made it through it would blow the timing.

Well, your conclusion seems reasonable, but it may be a bit more complicated than that. 
 

We are discussing this based on a wish of best SQ, obtained by lowest jitter, phase noise, and whatever more is mentioned in John’s white paper. (Well, at least I am). 

The 10GB transport system is much more. 
Here is some information and different test. Stressed eye test applies only to the optical part is my understanding. 
https://www.design-reuse.com/articles/5404/testing-10-gigabit-ethernet.html

 

Also if to follow your conclusion, we would have to purchase a system from our router to our DAC guaranteed from one single manufacturer. Most of us will purchase parts separately, from different manufacturers. 

Different equipment require different test, I would say. So far I’ve only focused on 1 GB network, as that’s the only interface available towards endpoint, DAC’s and streamers, unless your building your own PC. (Which may introduce other problems again). 
 

It seems there’s some good engineering hidden in SFP design which we are after. 
I don’t know if parameters in managed switches will help us in any way, like QoS or similar. 
However it’s (or should) already beyond any doubt, be accepted that switches matters in certain (most?) setups. The way @plissken is doing this, a switch won’t matter. 
A 1GB stick would be equal in his case I think 😀(His test only proves jitter won’t exist if buffers is in use). 

Have a look at this white paper. https://support-kb.spirent.com/resources/sites/SPIRENT/content/live/FAQS/10000/FAQ10597/en_US/How_to_Test_10G_Ethernet_WhitePaper_RevB.PDF

Does it actually have much relevance for what we’re after ?

 

Isn’t John’s white paper then more relevant.

There is some interesting test that may be carried out. 
Take the Mikrotik switch add, a RJ45 module towards an ultraRendu. (Or microRendu). Then test  it against etherRegen inserted. Any difference between etherRegen in the chain or not. We may also use a 2960G as well for a third setup. With switches in the chain, you would add SFP’s as well. (One SFP+). 

 

Add a FMC (opticalModule) in the chain and test. Does 10GB FMC exist BTW ?
 

Use power supplies like LPS 1.2 and/or Paul Hynes SR4T. 
 

Exchange the ultraRendu with an opticalRendu and do test. Inserting an etherRegen seems probably a bit odd, but anyway it interesting to know if any difference. 
 

Do same test with Lumin. Should be very interesting if you can alter the inputs to Lumin on the fly. 
(Hm, have Lumin huge buffer ?)

 

 

 

[R1200CL]

9 minutes ago, jabbr said:

To make another explanation point, consider that 10Gbe UI is 1/10 that of 1Gbe and 100 Gbe 1/100 of 1Gbe, so the allowable amount of jitter goes down by an order of magnitude or two. That means that *everything* needs to get that much better.

 

Ok now realize that the 100 Gbe and 200 Gbe NICs which run on the PCIe bus are powered off the backplane with bock standard power supplies. They still meet these insane standards! The engineering required is mind boggling!

Is Ethernet a protocol or transfer technology relevant when we go above 10GB ?

Im asking course there is almost no modules in SPF+ and above that supports 1 GB Ethernet that we must have. (Unless you says we make the discussion only relevant for computer endpoint). 

[R1200CL]

5 minutes ago, jabbr said:

If someone thinks that there is jitter transmitted through a switch

Eh.., Just to be sure:

Do we agree on switches can transfer jitter/ phase noise etc ?

[R1200CL]

22 minutes ago, jabbr said:

Furthermore no 1Gbe switch vendor has demonstrated better than 0.025 UI jitter when jitter has been injected. 

Isn’t that a acceptable number ? 

What is the accepted number in order to pass the test (10GB) ?

 

So let’s take a 10GB switch then, (like the Mikrotik) and add a RJ45 SFP and also the SFP+ FTLX1471D3BCV, as this is the only modules should that will fit today’s equipment, (unless your building a PC endpoint), should I expect both those two cases to be better jitter etc., compared to a one GB switch?

[R1200CL]

26 minutes ago, jabbr said:

They should both pass the stressed eye pattern/stressed receiver test. 

Thanks. Good to know. 
 

27 minutes ago, jabbr said:

My subjective impression is that the benefit is moving from copper to fiber (at 1Gbe).

I think most will agree to that, at least if proper equipment is used.
 

I would like to see fiber and SFP+/SPF28 is the standard for audio streaming, DAC’s and endpoints. 
As said before I don’t expect it to happen, but if one of Sonore, Uptone or SOtM releases products that complies with part of the 10GB standard, maybe others will copy.
 

29 minutes ago, jabbr said:

I can’t say that moving to 10Gbe has a SQ benefit, rather for anyone who is concerned about Ethernet jitter — it’s a non-issue.

Well, moving to 10GB gives us an expectation of a jitter and phase noise free transfer. Which is a good thing. After all handling of jitter and phase noise is what the etherRegen does, and it didn’t need to comply with 10GB specifications to do. 

 

Since you expect both those modules comply with 10GB standard outputting 1 GB, my suggest test would be interesting. Something for the Novel tread maybe to play with. 
 

Maybe I purchase a Mikrotik (And sell my etherRegen)...😀

I just emailed them for jitter measurements. (Yes, I probably won’t get it).

 

[R1200CL]

Can all these be used in audio ? (I haven’t a clue if that is a valid question). 
 

I just copied from Finisar headers from their chart. 
 

Fast Ethernet Optical

Gigabit Ethernet
1x Fibre Channel
2x Fibre Channel
4x Fibre Channel
8x Fibre Channel
16x Fibre Channel
32x Fibre Channel
SONET OC-3

SONET OC-12
SONET OC-48

SONET OC-192
SONET OC-768

OTN OTU3
OTN OTU4
10x Fibre Channel
10G Ethernet

25G Ethernet
40G Ethernet

100G Ethernet
200G Ethernet

IB QDR
IB FDR
IB EDR
IB SDR

1000BASE-T
PON

[R1200CL]

1 hour ago, plissken said:

Their white paper works against them however. Boiled down it makes two points:

Well, probably @JohnSwenson should answer. On the other hand measurements will come one day. (And you made three points, not two 😀)
 

1 hour ago, plissken said:

1. The faster your wire speed the better (since this equates to less phase noise/jitter)

My understanding is this is a consequence of the 10GB requirements. We would be happy with much less. Actually there is a low limit to how much speed a streamer can consume 😀

(unless an huge buffer). 

 

1 hour ago, plissken said:

2. Go optical since it's a low and high impedance leakage 'moat'.

I think many will agree. 
However, since many didn’t have that option, etherRegen served that purpose.

I really hope the future is optical. New proper SPF’s may be a bit expensive. Can we hope for Finisar or similar develop a audiophile version 😀

We would for sure wait until SFP is a normal option in the consumer marketed. Many haven’t discovered RJ45 yet, and just stated to do USB properly. 
 

1 hour ago, plissken said:

3. It works against them since they operate at 100MB so you have the largest amount of time of signal on wire and it's copper.

That has been very good explained by @Superdad many times. 
You should know better. With such a comment, it seems you have an hidden agenda to put Uptone in a bad light. 

 

1 hour ago, plissken said:

At least the other 'audiophile' switches I've seen give you 1GBe.

Really ? Do an audiophile switch exist ? Aren’t they all bad copies based on John’s always willing to share his knowledge. You may have something to learn there 😉