I am not sure if this is the correct site to post this question and I am more a software type of guy that needs to get started with Networking, so please bear with me if this sounds stupid... Having said that here is my situation:

I am considering purchasing a SFP+ Core switch ('WS-C4500X-16SFP+' - it has 16 x 10 GE SFP+ port only - no RJ45) and then want to connect this to a 1G CISCO switch (WS-C3850-48P-S) with an SFP+ uplink module. The "Edge-to-Core" connection should be 10Gbps. (The connections to the clients will be 1Gbps. )

The questions I ran into when I was planning this were:

  • how do I connect the 2 switches when the edge/client switches are on different floors in the building.
  • What cables do I use? I have short 3' cable but this will not work when the switches are 30'-50' apart.
  • Is this configuration supported?

I will ask these questions to my consultant and vendor but I would like to get some knowledge on this myself so I don't get talked into something that will not work. Looking on the net I have not found anything that makes sense (to me).


You will need SFP modules/transceivers for both switches, and the appropriate type of fiber cable. I'm assuming your desired speed is 1Gbps.

You'll probably want to run multimode fiber. Is that already in place?

If you only have Cat5/6, you can also use copper adapters to link the two.

enter image description here

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  • Thank you @ewwhite! I edited my post slightly. The speed should be 10Gbps. Currently I only have copper cables in place. Does this mean I have to run fiber cables? I thought SFP+ is also copper based... How do the copper adapters work? Is the picture in your post the adapter or module? – philips Apr 23 '16 at 18:45
  • For 10GbE, you will need fiber cabling and transceivers on both ends. – ewwhite Apr 23 '16 at 18:47
  • Thank you and that makes more sense and confirms my suspicion. With transceiver you you mean the module that gets plugged into the switch right? This would mean I only need to get the module for the edge switch which because the Core (C4500X) has already 16 SFP+ ports. – philips Apr 23 '16 at 20:49
  • You will need a transceiver for both switches. – ewwhite Apr 23 '16 at 20:50
  • Thank you. I get it now. The transceiver is a device that basically functions as an adapter. It gets plugged into and SFP port and one can then plug in an RJ45 into the transceiver. – philips Apr 26 '16 at 22:21

The 16 SFP+ Port also support 1G SFP Module. I think you can use the MMF SFP Module for both switches. glc-sx-mm SFP module can transfer up to 550m with OM1 OM2 MMF Fibers. Do you think so?

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