In reply to a post by candlerb:

In reply to a post by PaulKirby:

Also I am with another provider who use DHCP, not had any issues so far, will also be replacing CAT Cables to LC to LC OM5 Fibre Cables, so once they are in I shouldn't need to replace them unless damaged.

I suggest you *don't* buy OM5 - buy OS2 instead.

Multi-mode can never achieve high speeds over long distances, due to physics, whereas single mode will work at *any* speed and over very long distances.

You may find that the transceivers are a bit more expensive at very high speeds (40G/100G). Also, the easiest to obtain transceivers use 4 pairs at those speeds (8 fibres, usually presented as an MPO connector with 12 fibres). You *can* get single mode transceivers that use a single pair at 100G, although today they might cost the same as a second-hand car

Anyway the point is, OS2 is much more future-proof than multi-mode. Most modern data centres have abandoned multi-mode completely.

Oh really?
I read that multi-mode was fine for in homes etc and is faster than single-mode, but that single-mode can go a lot longer distance.

My Rack is in an empty upstairs room that is very accessible everywhere here with a reasonable length cable. Like each cable would be less than 15m to 20m.

Well I already have some MM Transceivers and MM Fibre cables along with some 40Gbit QSFP Transceivers (basically 4x10Gbit) off Amazon for free so I was going to just use those and add to that, its not like I would benefit using Single-Mode fibres due to the lengths would not be that long. But sure if it was going to be a long run etc.

But I will see once I rip out the old copper cables, plus I need to move the ONT upstairs too, so everything is located in the same room and easily accessible.

But thanks for that, I will have to look in my Fibre Stuff Box and see what ones I have, I know a lot are MM, but some was SM.

*** update ***
Just checked and my SC/APC cable is fine and will be used to relocate the ONT.
All but one LC to LC cable are OM4 in various lengths, my MPO to 8X LC Cable is OM3, MPO to MPO is OM3
I do have one short LC to LC which is OS2 which was also sent with the 1Gbit, 10Gbit Transceivers.
And I have a range of SFP+ Transceivers that are Multimode.
Also had a couple of 10GBit DAC Cables to try out.
Plus several 10GBase SFP+ RJ45 Transceivers.

---
Paul

Edited by PaulKirby (Wed 14-May-25 20:46:13)

In reply to a post by candlerb:

You *can* get single mode transceivers that use a single pair at 100G, although today they might cost the same as a second-hand car

Anyway the point is, OS2 is much more future-proof than multi-mode. Most modern data centres have abandoned multi-mode completely.

You can also get BiDi 100G that run on a single core of OS2. I didn’t have much luck with one supplier but FS.com supplied ones had much better compatibility. They were around £545 each.

To match a second hand car price try genuine branded Cisco optics 😂

In reply to a post by PaulKirby:

I read that multi-mode was fine for in homes etc and is faster than single-mode, but that single-mode can go a lot longer distance.

MM is definitely not faster than SM, but you're right that SM can go longer distances.

For speeds 1G-100G, There's a table of the most common standards on pages 15-16 of this: https://nsrc.org/activities/agendas/en/cndo/networki...

MM over a few tens of metres will be fine for home use up to 10G. Beyond that, you'll need to install multiple pairs to get 40G. Whereas SM you could run up to 800G over a single pair with the right optics (and budget) using today's technology - and faster in future.

Agree. There's a slight price premium with OS2 fibre and transceivers but for the 8 fibre cables I have in the house to trunk various switches, it's really a no brainer. My summer house at 100 ft away at the end of the garden would have be a concern with multimode, but with OS2 it's 'whatever'.

If you're trunking through the building, buy fibre pre-terminated fibre and double check the length you need. Also make sure you use a proper duct for outdoor use and use armoured cable. Bend radius concerns are the last thing on your mind while yanking through cable through a small space. Tell me why I know.

Single mode fibre far more flexible really not juts from a LAN perspective: allows you to run other service over the fibre. Example I run TV/Sat/radio over mine from a FIRS dish / antenna head end