Optical Network Configurations

[charlesphoto]

I took the attenuators off, and finally had time to really listen (vs family here and there) and must say the single mode Finisair's are a nice upgrade from the TP-LINK multimodes. It's subtle, but there, and esp noticeable over longer term listening. Less fatiguing. The devil is in the details, I guess, with these crazy digital chains. Thanks @kennyb123 others for tuning me in to these. 

[NYCEnglish]

Does anyone have a recommendation for a single mode cable? Thanks.

[StreamFidelity]

10 hours ago, NYCEnglish said:

Does anyone have a recommendation for a single mode cable? Thanks.

 

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

[NYCEnglish]

6 hours ago, StreamFidelity said:

 

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

 

Thanks, much appreciated!

[NYCEnglish]

Another question: I've heard opinion that longer runs are better than shorter, any truth to this? 

[StreamFidelity]

2 hours ago, NYCEnglish said:

I've heard opinion that longer runs are better than shorter, any truth to this? 

 

You can't say that in general.

 

If the transmitter couples light into the fiber at -20 dBm and the weakest signal that the receiver can still recognize must have a power of -30 dBm, the difference between the two values is 10 dB. This means that the system must have an attenuation of at most 10 dB before the signal becomes too weak and the receiver can no longer process it.

 

But what if the receiver were coupled to a transmitter that has a power of -5 dBm? The signal would be too strong and the receiver would be blinded. With optical systems, care must be taken not to overload the receivers, as this would be just as harmful as a signal that is too weak.

I bought a 2m and 20m fiber optic cable. For me the 20m fit better. You have to try it.

[NYCEnglish]

Thanks, that makes sense. Fortunately, it's cheap and easy to try different lengths.

[plissken]

3 hours ago, NYCEnglish said:

Another question: I've heard opinion that longer runs are better than shorter, any truth to this? 

 

Here is where I think that comes from: 40Km and higher optics.

 

If you use 40/80Km or greater optics you can't use them with short cables because the optics will burn out.  Single Mode and 10Km Multi-mode are fine.

[robi20064]

Does anyone have any hands on experience with the Mikrotik RB4011iGS+RM? It has 10 gigabit ports plus one SFP+ which is directly linked to the CPU. The 10 gigabits are split into 2x5 and each group linked to a Realtek controller.

[NYCEnglish]

Add me to the single-mode fan club!

 

I'm using a single-mode cable from the same manufacturer as Sonore use for their multi-mode cables and the Finisar modules.

 

A clear uptick in SQ in my system - better separation, and a little more relaxed presentation. No downsides for me.

 

Thanks to everyone recommending this approach.

[Account Closed]

On 7/12/2020 at 1:50 PM, jabbr said:

 

These are compatible with 1000base-LX and as @plissken says don't need attenuators, for some reason some folks have used 1000base-EX modules (40km) and these do benefit from attenuation over short distances. FWIW I see no reason why EX modules might be better, indeed they use more power, so would avoid unless some additional info.

Where did you get these Finisar FTLF1324P2BTV-B1 units? I see them on Amazon and they are pretty high there (about $100 ea). Was wondering if there is another source that might be cheaper.

 

Thanks,

 

My optical Rendu and OM come Friday with the standard SFPs and cable but I will try single-mode as well.

[ericuco]

1 hour ago, bobflood said:

Where did you get these Finisar FTLF1324P2BTV-B1 units? I see them on Amazon and they are pretty high there (about $100 ea). Was wondering if there is another source that might be cheaper.

 

Thanks,

 

My optical Rendu and OM come Friday with the standard SFPs and cable but I will try single-mode as well.

Have you checked eBay? Lots of used SFP modules are usually available. I have bought most of mine from eBay.

[charlesphoto]

1 hour ago, bobflood said:

Where did you get these Finisar FTLF1324P2BTV-B1 units? I see them on Amazon and they are pretty high there (about $100 ea). Was wondering if there is another source that might be cheaper.

 

Thanks,

 

My optical Rendu and OM come Friday with the standard SFPs and cable but I will try single-mode as well.

I bought mine from Calhoun technology here in the States. $30 refurbished. Oh, looks like they're now $35. You guys gotta stop talking about this stuff!

 

https://www.calhountech.com/products/finisar-ftlf1324p2btv-b1.html?utm_source=googleshopping&utm_medium=cse&gclid=CjwKCAjwrcH3BRApEiwAxjdPTezPd_BuVXKGcM-Fi4FT4OPgDmpgaiCLhtinhwBKDxotVN1NkhEsrxoCl6gQAvD_BwE

[NYCEnglish]

I have some spares, I can do $25 each incl shipping if you're in the US. That was my approximately my cost.

 

[Account Closed]

13 minutes ago, NYCEnglish said:

I have some spares, I can do $25 each incl shipping if you're in the US. That was my approximately my cost.

 

That would be great! I will PM you.

 

Thanks

 

[Account Closed]

43 minutes ago, ericuco said:

Have you checked eBay? Lots of used SFP modules are usually available. I have bought most of mine from eBay.

eBay was out of stock.  Thanks

[Account Closed]

33 minutes ago, charlesphoto said:

I bought mine from Calhoun technology here in the States. $30 refurbished. Oh, looks like they're now $35. You guys gotta stop talking about this stuff!

 

https://www.calhountech.com/products/finisar-ftlf1324p2btv-b1.html?utm_source=googleshopping&utm_medium=cse&gclid=CjwKCAjwrcH3BRApEiwAxjdPTezPd_BuVXKGcM-Fi4FT4OPgDmpgaiCLhtinhwBKDxotVN1NkhEsrxoCl6gQAvD_BwE

Thanks

[jabbr]

22 hours ago, bobflood said:

eBay was out of stock.  Thanks

Just be patient

[jabbr]

On 7/29/2020 at 5:41 PM, bobflood said:

Where did you get these Finisar FTLF1324P2BTV-B1 units? I see them on Amazon and they are pretty high there (about $100 ea). Was wondering if there is another source that might be cheaper.

 

Thanks,

 

My optical Rendu and OM come Friday with the standard SFPs and cable but I will try single-mode as well.

Ive gotten most everything on eBay, including my Mellanox SN2700 switch and ConnectX-5 NICs, Solarflare NICS, QSFP28 modules etc etc. If you think $100 for a module is a lot, I have done that retail for $5K. Do you need that exact model number?

[Account Closed]

1 hour ago, jabbr said:

Ive gotten most everything on eBay, including my Mellanox SN2700 switch and ConnectX-5 NICs, Solarflare NICS, QSFP28 modules etc etc. If you think $100 for a module is a lot, I have done that retail for $5K. Do you need that exact model number?

Thanks, I got a pair from a member who had spares. See the post just above. Thanks to all for posting these links as others will find them helpful.

[giordy60]

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

 

economico e buono FS LC UPC a LC UPC Duplex OS2 Single Mode PVC (OFNR) Cavo patch in fibra ottica da 2,0 mm

 

mediaconverter and switch from the same house, can you tell me something about their reliability? 

thank you.

[StephanLJ]

On a 1 meter (3 foot) single mode cable with an SFP+ for 10 km what would you recommend as attenuation (db?) and what would you use for 20 meters SFP+ and also 10km. 

Thank you for clarification.

[jabbr]

On 9/18/2020 at 5:28 AM, StephanLJ said:

On a 1 meter (3 foot) single mode cable with an SFP+ for 10 km what would you recommend as attenuation (db?) and what would you use for 20 meters SFP+ and also 10km. 

Thank you for clarification.

Attenuators are not recommended with 10Gbase-LR modules. Attenuators are used with 10Gbase-ER modules but I don't recommend those for home use.

[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

 

[jabbr]

59 minutes ago, R1200CL said:

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 ?

 

 

Yes if both support 1000base-LX you should be good to go.

 

I have no knowledge of any SQ difference between different lasers, I can't say there isn't. The dual rate 10/1 modules seem to be DFB, so you could try Fabry-Perot vs DFB in the switch and try to tell SQ difference. I'd suspect not. I would suspect only the optoelectronics at the endpoint might matter.