Fiber Connectors

[londint]

We have some fibre uplinks on our patch panel and some of them are circle in shape and some are square in shape. What are the differences in shape and why are they different. Also where can I find more information on this. What are they called as well?

Thanks

[rjackson · Accepted solution]

The circular ones are called ST because they snap and twist on. They look like a small BNC connector. The male has two posts on the outside and the female has two slots that twist onto the posts. These are old style.

The square one is an SC for snap and click. These are the newer style connectors. The cable has two keyed connectors that can be bound together.

I have not seen any current cisco equipment that uses the ST. All gbics use SC connectors.

[londint]

Thank you ever so much.

Thanks

[#4]

In my network, the ST connectors are used to terminate single and multimode fiber between buildings. SC connectors are used between all Cisco device to device and to fiber NIC's.

I have found out the hard way that it is easy to break the fiber while inserting or removing SC connectors Broken fiber inside the SC connector is evidence of a bad assembly - not mishandling. Be sure to check continuity with a light if it seems the SC patch cable is not working.