Pre-terminated fibre: ST-ST or SC-SC?

[dhicks]

Hello All,

We have a new building being built. It is going to be linked to our old building and to our sixth-form via a couple of runs of fibre optic cable. The electrician is going to be getting a couple of chunks of pre-terminated fibre. Does he get cables with ST-ST connectors or SC-SC?

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David Hicks

[timbo343]

You prob want SC to ST. I know that I use an SC connector to go into our switches via a GBIC and then the ST end connects to the Fibre cable.

[srochford]

I was going to agree (because I think that's what we do) but I looked on the videk web site and I'd guess you could also do SC to SC - I much prefer the SC connectors because I'm always worried about breaking ST (I did many years ago when it was very expensive to fix it ...)

[dhicks]

You prob want SC to ST. I know that I use an SC connector to go into our switches via a GBIC and then the ST end connects to the Fibre cable.

Connect what to the fibre cable? As far as I can make out we just get one piece of fibre cable with 8 SC or ST dangly bits on the end that we plug straight into GBIC modules that we buy for our switches. Do you reckon this means we simply get a cable with SC connectors so we can plug it straight in to our switches?

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David Hicks

[Netman]

Connect what to the fibre cable? As far as I can make out we just get one piece of fibre cable with 8 SC or ST dangly bits on the end that we plug straight into GBIC modules that we buy for our switches. Do you reckon this means we simply get a cable with SC connectors so we can plug it straight in to our switches?

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David Hicks

With pre-terminated you should (IIRC) still connect them into a box either end and then use the relevent patch cable to connect to your switch. We just put one in and ordered LC-LC...

[timbo343]

Connect what to the fibre cable? As far as I can make out we just get one piece of fibre cable with 8 SC or ST dangly bits on the end that we plug straight into GBIC modules that we buy for our switches. Do you reckon this means we simply get a cable with SC connectors so we can plug it straight in to our switches?

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David Hicks

We buy a Fibre patch panel box (Mills Ltd - cable management and specialist tooling for the communications industry). The SC - ST patch cable connects the GBIC or Transciever to the fibre optic cable. Pretty simple really, but the way that you do it would work. The way we do it, just protects the main fibre cable.

[plexer]

The pre terminated fibre should still end up in a fibre tray at each end, from the connectors on the front of that fibre tray you plug in your fibre patch leads to your switches.

You wouldn't plug the ends of the preterminated fibre into your switches.

So depending on what fibre trays you are now going to buy will dictate wether you want sc to sc or st to st.

Ben

[localzuk]

We use ST for all panel - panel installs, then do ST-whatever (which happen to be LC for everything at the moment, but we had SC and LC in the past).

[dhicks]

We use ST for all panel - panel installs, then do ST-whatever (which happen to be LC for everything at the moment, but we had SC and LC in the past).

Right-oh - thanks All, looks like I get ST-ST cables, some fibre patch panels and a 19" rack for my office to put the switch and patch panels in.

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David Hicks

[john]

ST at each end, in fibre panel then patch lead from the panel to the converter / switch as required. As has been said reduces the expense of damaged connectors etc

[SeanVin]

I ordered LC-LC pre-terminated cable last week, our consultant implied we should go straight to the switches to reduce connection losses, however I am going to use patch panels, I just do not feel comfortable going straight to the switch.

[SYNACK]

ST is the older technology and I would only use it if your pre-existing fiber is also terminated as ST and you want to keep it all the same.

ST has a number of disadvantages over SC such as ST takes up more room in the patch panel, is more prone to breaking due to twisting and is more difficult to plug in an unplug in comparison.

The SC connectors are all but standard now in new NZ installations as they are more compact, also with the fixed SC plugs you are far less likely to plug a Tx fiber into an Rx fiber as the connectors can come molded together in the right order to start with.

[TronXP]

also with the fixed SC plugs you are far less likely to plug a Tx fiber into an Rx fiber as the connectors can come molded together in the right order to start with.

That is providing the cable monkey who installed the fibre terminated them in the right place. Since coming to this post I have found 3 - 4 fibres in SC trays which are terminated the wrong way!

[Geoff]

All our fibre trays use the ST type connectors. Then we use ST-SC or ST-MTRj depending on if we're connecting up a new ProCurve with a SC miniGBIC or one of our old 3coms.

[SYNACK]

That is providing the cable monkey who installed the fibre terminated them in the right place. Since coming to this post I have found 3 - 4 fibres in SC trays which are terminated the wrong way!

They are easy enough to swap round if you have the proper panels but you are right you are at the mercy of the usually under qualified cable mule who dragged it through the buildings.