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cisco 3550 EMI

I have 4 switches 3550-48 SMI cascaded I need to add 3550 EMI as layer 3 switch

Quistion: Can I cascade 3550 EMI with 3550 SMI? or should I use GBIC fiber modules?


Cisco Employee

Re: cisco 3550 EMI

I'm not sure what you refer by cascading. Are you referring to stack? Connecting 3550 EMI using GBIC Fiber module would be a better design

New Member

Re: cisco 3550 EMI

Yes I meant stack. I used to be Nortal



Re: cisco 3550 EMI

Prashanth is right, a direct point-to-point Gigabit connection to the 3550-EMI would give better performance with what you've got. It'll run in full-duplex mode.

You can use GigaStack GBICs to do point-to-point connections, instead of 1000BASE-T or -SX GBICs. But you're limited to a maximum distance of 1 meter between units, vs. 100m of the -T GBICs or 220 to 275m of the -SX GBIC.

But you can add the 3550-EMI to the GigaStack "cascade". The in/out cascade configuration causes the Gigabit "backbone" between the switches to run at half-duplex. This isn't bad, if your traffic needs there are light to moderate. Also, it's very cost-effective. But if you need top performance, it's not the best approach -- a 3550-12G and point-to-point connections to each switch instead of GigaStacking would be ideal. Also, more expensive.

For somewhat better performance using just GigaStack GBICs, you could create two GigaStacks of two 3550-48-SMI switches each, and then connect each of those mini-stacks to a GBIC port of the 3550-EMI. Think of it as "segmenting" your GigaStack backbone.

Ultimately, what's best for you really all depends on your traffic needs, and your budget.

Hope this helps.

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