SFPs and 2.5G options

[Red-Five]

Noob question; client is wanting to replace old Adtran switches that currently have a SFP 2.5G link over OM1 fiber.  The runs are too long to support 10G and they don't want to replace the fiber.  How do I get a Meraki switch solution to support the same 2.5G link over fiber?  Specifically what SFP & config would allow that?  Thanks all.

[GIdenJoe]

I'm sorry but the options are 1G, 10G, 40G, 100G.

I have never heard of 2.5 G SFP fiber.

You can have 2.5G and 5G copper links but not fiber.

[Brash]

Best to check with your Meraki rep to confirm 100% but I've only ever seen 2.5gbs on rj45 switchports. Fiber has always been 1/10/40/100gbps.

The ms355 documentation seen to support this as well.

https://documentation.meraki.com/MS/MS_Overview_and_Specifications/MS355_Overview_and_Specifications

Additionally there's no 2.5gbps SFP's supported.

https://documentation.meraki.com/General_Administration/Cross-Platform_Content/SFP_and_Stacking_Acce...

[Inderdeep]

@Red-Five : The best option to check here with your options, Put your requirement and will tell which devices are compatible. I am also agree with @Brash 
Optics Compatibility Matrix (cisco.com)

[cmr]

@Red-Five I must admit that I'd never heard of 2.5Gbps fibre links, but it does look like they exist as per your comment, see the link for a transceiver here: https://www.optcore.net/product/2-5g-multi-mode-850nm-300m-sr-sfp-optical-transceiver-module/

In terms of what devices you can plug this into, I'm really not sure!  You could try an SFP+ port and see what happens...  Though I think it is for fibre channel or SDH.

[cmr · Accepted solution]

Looking further I believe this is an Adtran specific feature, I can't find any other vendors equipment that supports it...

[GIdenJoe]

It's definitely not ethernet.

[burnz]

2.5G is it maybe gpon?

[Red-Five]

Thanks everyone for the info and suggestions - great community here.

Not 100% this was an Adtran only feature, but I do believe this was something vendors were doing years ago when fiber links were young; perhaps as a cost saving option.  Best I can see the industry has settled on the existing tiers of 1G, 10G, 40G, and 100G and I can't find any current vendors selling this.  So, for me, it's a question to the client regarding upgrading their physical fiber to support 10G and moving forward.  Since I have the 2.5 SFPs I might try them in my new switch, just to see what happens, but I'm not expecting them to function.

[GIdenJoe]

Usually SFP's adhere to standards like 1000BASE-SX or 10GBASE-LR or special types like BiDi, BX, ER, ZR which describes several requirements like wavelength, type of led/VCEL/laser used to transmit signals and more.  All SFP's of the vendors then comply with these standards so a switch from vendor A will successfully make a connection to another switch/router/server's SFP module.

Usually in ethernet standards you have ports running a single speed like 1 Gbps and only support SFP modules.  But you also have dual speed ports like 1/10Gbps SFP+ ports.  And even beyond 40/100Gbps ports.

If your customer has an old fiber plant you'll need to stick to 1 Gbps links but you could bundle 2 or 4 or 8 links to upgrade your inter switch bandwidth that way.