I have bought two WS-2948G switches from cisco for a lab. I now need to buy two additional modules for them WS-G5484. I've never worked with fiber so I was wondering if there are differences in fiber cables and what type of fiber cable I should use on these?

  • @SimonJGreen: I think this tag renaming was anticipated. Cisco 2900 are routers, not Cisco Catalyst (like the 2948G). Feel free to join the tag discussion at meta though ;)
    – petrus
    May 7, 2013 at 22:19
  • WS-2948G-L3 is technically a Catalyst switch, but configured like a Cisco router, using BVI interfaces to actually handle switching. I really, really dislike working with them.
    – nicotine
    May 7, 2013 at 23:02
  • In addition to the answers below I think you should read up on fiber and understand how various types work, what issues they have, etc. There are a significant number of types of multi-mode fiber. You want to have a handle on what they are and when you'd use them (which might make another good question). May 8, 2013 at 7:57

3 Answers 3


The WS-G5484 is a multimode fiber connector. If you're using standard multimode fiber (62.5 micron), you should be about to get around 300m distance out of them. With 50 micron fiber, that number should go up to around 500m.


Generally when you're working with fiber you have to be concerned about two things:

1. Type of fiber:

  • Long-Haul: Single-Mode, used for long distances.
    • Example: Across a city
  • Short-Haul: Multi-Mode, used for generally shorter distances.
    • Example: Internal to your campus/building

*Caveat: There are different types of Single-Mode and Multi-Mode.

2. Connector type:

Both Long and Short haul fiber connects into your transceiver with a connector. Your WS-G5484 uses a SC connector type. More modern connectors use smaller LC type connectors.

Like Tom Says, since you have the fiber transceiver already (WS-G5484) this means you are going to need a Multi-Mode fiber patch cable with SC connectors.


In addition to the exact answer about MMF and SC-SC connectors, the PDF presentation linked here from Richard Steenbergen @ NANOG57 is the best introduction to fibre you'll ever find.

Everything You Always Wanted to Know About Optical Networking – But Were Afraid to Ask

Not the answer you're looking for? Browse other questions tagged or ask your own question.