SFP Compatibility Question

[mdeang]

Hi Ma'am / Sir,

Good Day! I have an inquiry with regards to the 1 GB SFP and 10 GB SFP+ Ports. If I plugged a 1 GB SFP Module into a 10 GB SFP+ Port of a Network Device, will there still be a connection, and what will be the output? How about if I plugged a 10GB SFP+ Module into a 1 GB SFP, what will be the outcome? Thanks!

[Otanx]

Typically a SFP+ port will accept a 1G SFP, and run at 1G. This is pretty common when upgrading systems. You swap out a 1G switch with a 10G one. Keep using the 1G optics until you can get the other side upgraded as well. If you put a 10G SFP+ into a 1G SFP slot it will not work. There are some dual speed SFP+ that are 1G/10G. I don't know what happens if you plug those into an SFP slot. I would assume they don't work, but they might.

-Otanx

[deanwebb]

SFP+ ports typically support SFP modules, but at lower data rates.

SFP ports typically do NOT support SFP+ modules, as the SFP+ modules can't fall back to lower data transfer rates.

EDIT: Otanx ninja'd me!