SFP module for Netgear GS110TP?

[occamsrazor]

Hi,

I have a GS110TPv2 switch acting as my main switch, with two GS108Tv2 switches in other rooms powered by POE. All computers are connected via Cat5E. Everything works perfectly, it's a great switch.

I'd like to experiment with using the SFP capability to connect to one Mac Mini from the switch via SFP to a media converter like this one, and then on to the Mac Mini via Cat5E.

I'm reasonably familiar with networking but have never used fiber before. I understand the GS110TPv2 has 2x SFP ports, but reading online it seems I may need to buy a "SFP module" to install in the switch, it doesn't come with them. Is this correct?

Looking online I see two or more types of modules described as either 1000Base-BX/LX/SX or MiniGBIC. Could someone kindly advise which type of module I should be looking for that will be compatible? And ideally recommend a particular model if you have experience with it in this switch? I'm just looking for something cheap, the cable run will only be a couple meters, the objective is to achieve electrical isolation of the Mac Mini, which is used as an audio computer, from the rest of the network via optical cable, nothing else.

Thanks

 

[azazel1024]

MiniGBIC is another name for the SFP form factor.

What matters is having the same type of SFP transciever on either end, whether it is LC, or some other type for fiber connector.

Most are 1000base-SX, but of course others exist.

http://www.ebay.com/itm/Cisco-GLC-S...723?pt=LH_DefaultDomain_0&hash=item232b5c8bb3

A couple of those should work just fine in the Netgear switch (I do not believe that Netgear does module validation, I know some like Cisco and Dell often DO do module validation, IE if you put a non-Dell SFP module in to a Dell switch, it won't work. I am not sure if that is universal across Dell/Cisco or not).

They have LC ends as near as I can tell, so just get some LC fiber to go with.

I'd have to double check, but I am 99% sure those are the modules I have sitting at home along with a meter of LC ended multimode fiber. My SFP modules were hand-me-downs from my brother and I splurged on $3 of fiber. Mostly so I could test it out between my two switches that are stacked. Because.

That said, I DO have a couple of fiber projects in and outside of my house, it just won't be for another couple of years before they are needed/it is relevant (planning on doing a fiber pull of two strands from my basement networking rack to an addition I am putting in, as well as a pull of two Cat6 cables, run it to an edge switch in a closet in the addition and then wire the addition back to that closet. More economical than running the ~8 odd pulls from all around the addition all the way back to the basement on the other side of the house. Gives me future flexibilit on copper vs fiber and if push comes to shove, that is 4Gbps of trunked capacity to supply the ~8 drops in the addition). I also will do a run of two strands out to a shed I am tearing down and converting in to a 1 car garage on the other side of my property...but that is probably for 4-6 years from now.

 

[occamsrazor]

MiniGBIC is another name for the SFP form factor.
What matters is having the same type of SFP transciever on either end, whether it is LC, or some other type for fiber connector.
Most are 1000base-SX, but of course others exist.

Thanks for taking the time for a detailed explanation, I think I understand better now. So SFP a.k.a. MiniGBIC is really just a standard for the type of "slot" that a fiber transceiver goes into, it isn't a different type of transceiver in itself?

So actually for the fiber transceiver box side, the link I gave:

http://www.tp-link.com/en/products/details/?categoryid=225&model=MC220L

....is just an empty SFP slot and I would also need a module to go into that slot. And maybe I'd be better off just buying one with the transceiver module built-in, like these:

http://www.tp-link.com/lk/products/details/?model=MC210CS (single-mode)
http://www.tp-link.com/lk/products/details/?model=MC200CM (multi-mode)

Re: single-mode vs multi-mode.... Am I right in saying that generally multi-mode is cheaper and easier to work with, and for a short run of a few meters would be the one to go for?

Also, someone mentioned that these SFP ports on the switch can only be used as an uplink to another switch, not to a computer directly - anyone know about that?

Thanks....

 

[azazel1024]

Thanks for taking the time for a detailed explanation, I think I understand better now. So SFP a.k.a. MiniGBIC is really just a standard for the type of "slot" that a fiber transceiver goes into, it isn't a different type of transceiver in itself?

So actually for the fiber transceiver box side, the link I gave:

http://www.tp-link.com/en/products/details/?categoryid=225&model=MC220L

....is just an empty SFP slot and I would also need a module to go into that slot. And maybe I'd be better off just buying one with the transceiver module built-in, like these:

http://www.tp-link.com/lk/products/details/?model=MC210CS (single-mode)
http://www.tp-link.com/lk/products/details/?model=MC200CM (multi-mode)

Re: single-mode vs multi-mode.... Am I right in saying that generally multi-mode is cheaper and easier to work with, and for a short run of a few meters would be the one to go for?

Also, someone mentioned that these SFP ports on the switch can only be used as an uplink to another switch, not to a computer directly - anyone know about that?

Thanks....

Correct, just an "empty box". Of course it does a lot more than that, but you would need an SFP transceiver/module to go in it.

I would NOT get one with a built in transciever, I could be wrong, but neither of those other TP-Link media converters look like they are rolling LC fiber ends for the modules (though maybe they are).

Deffinitely go multimode. Cheaper and easier and it isn't just for short runs. 1000base-SX works up to, 430 meters? I believe. You can do 10Gbps with multimode at roughly 100 odd meters I think (maybe somewhat more?). That is with fairly standard fiber.

Single mode is generally stuff where you need KILOMETERS of fiber without repeaters.

So long as you have the same spec on both ends (generally 1000base-SX multimode) you CAN have whatever fiber transceiver on either end, it does not matter. It is generally easier to find fiber that has the same ends (I look for LC personally), but you can also find fiber with different ends so you could hook it up to two different module types (again, still must support the same spec 1000base-SX or BX, etc. though).

 

[occamsrazor]

I would NOT get one with a built in transciever, I could be wrong, but neither of those other TP-Link media converters look like they are rolling LC fiber ends for the modules (though maybe they are).

Looks like you are correct the multi-mode one is running an SC-Type connector. What is preferable about being LC ended? (I've no idea)

Deffinitely go multimode. Cheaper and easier and it isn't just for short runs......... Single mode is generally stuff where you need KILOMETERS of fiber without repeaters.

Thanks for clearing that up... So the checklist is identical transceivers, multimode, 1000Base-SX, LC ended.... How about a pair of these:

http://www.amazon.co.uk/dp/B00GS0NURG/?tag=smallncom-21

One for the switch, and one for the TP-Link converter with empty SFP slot.

Any idea how I might tell whether the SFP ports on the GS110TP are suitable for connecting directly to a computer, or are for uplink use only?

Thanks again....

 

[azazel1024]

You can connect them directly to a computer, but the computer will need a NIC that supports and SFP module.

They are a regular switching port just like any other, its just that instead of an RJ45 connector, there is a slot connector that a fiber to copper interface (IE the transceiver) plugs in to.

There isn't really much between connectors, just that it is nice to have "one standardized" kind, especially if you start getting in to a large number of fiber cables and transceivers.

 

[Terry Kennedy]

Looks like you are correct the multi-mode one is running an SC-Type connector. What is preferable about being LC ended? (I've no idea)

LC is small enough to fit into an SFP. It is the mini size connector that won the "format war" - there were other types, like MT-RJ. SC was the connector type that won the full-size format war - ST was common, and at one point the recommended connector.

Thanks for clearing that up... So the checklist is identical transceivers, multimode, 1000Base-SX, LC ended.... How about a pair of these:

Those should work, assuming the media converter at the computer end will accept them.

"Enterprise" networking gear (which includes both real enterprise gear and wanna-be gear) usually looks for a "magic signature" which prevents generic SFPs from working. Cisco is a major offender, though their (relatively) recent software allows you to override the check. That isn't necessary most of the time, as most of the eBay SFPs come pre-programmed with the magic signature.

You definitely want to use multimode (short reach) SFPs and cable. Single mode is used for longer distances, or when a site wants to standardize on a single fiber type. Because of the higher output power of single mode devices, you may need to use an attenuator to reduce the signal level to prevent over-driving the receiver.

Superfluous information for the curious - an SFP is pretty much just a serial electrical-to-optical converter - serial bits go in and serial bits come out*. That is convenient, since there are many Gigabit controller chips that connect to a separate copper transceiver (PHY) on the circuit board. That can be reworked relatively easily to adapt it to a SFP, or to make a dual-mode port which can be configured to use either a copper RJ45 jack or an SFP slot.

When 10GbE first came out, switch manufacturers wanted a way to add one or two 10GbE uplink ports cheaply. That meant that much of the expensive parts were in the (optional) plug-in transceiver. XENPAK and X2 (two early 10GbE transceiver form factors) were much more complicated than SFPs - the switch side was a parallel port and all of the SERDES functions were performed in the transceiver. As 10GbE became more popular, switches migrated to using SFP+ (the + indicates 10GbE capability - some switches can use a SFP+ as either GigE or 10GbE).

* This is a little bit of a simplification - there is a relatively large amount of "smarts" in a SFP, but devices don't need to deal with that if they don't want to - I have some fiber converter shelves that take "dumb" modules which simply have 2 SFP slots connected back-to-back, for things like wavelength conversion.

 

[fiberboy]

You could buy a SFP compatible with your switch. Fiberstore is a good option as they have varous SFPs compatible with many brands and they could provide customized service according to your requirements.