Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Fiber Bandwidth on Switches

I am confused about the maximum bandwidth needed to feed 3538xl switches.

If I have 48 ports running at 100Mbps, the bandwidth needed is 4800Mbps or 4.8Gig. If I am using single mode fiber that can run only 1Gbps, this is not enough. I thought I could run 3,4 or 5 switches using gigabit fiber linked with the gbit link?

A 6500 would be supplying the 3500's.

Thanks for any information on this as it seems to be a grey area.


New Member

Re: Fiber Bandwidth on Switches

Generally speaking the hosts are not eating up all pipe at the same time..

If you had 48 PC's all surfing the net on a T1 how much pipe are you usng ?? Not much..

Thats the reasoning..

So you need to determine the max bandwidth that will be used first..

In some cases if the hosts are pumping away all day at 100 meg flat out them you need to rethink the 3548 and go for say a Cat 4XXX and devote a blade to some gig ports


New Member

Re: Fiber Bandwidth on Switches

If u r running 100Mbps on 48ports ,u need 4.8g capacity on the backplane and not on the uplink.Cuz not all the 48 ports would be constantly pumping in 100mbps of data at the same time.1 gig for uplink is sufficient enough for a LAN that is terminating on a L2 switch like 3500 series.And if at all any of the port is pumping in 100mbps of data constantly, then u may consider a gig link to the switch instead of a fast-ethernet connection!Hope it helps.

CreatePlease login to create content