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New Member

Looking for advice on Core to Edge Switching Network Design

I believe this post is in the right area since my topic is Network Infrastructure regarding my corporate LAN.

We are a small company who just this year reached 100 employees. I am the multi-role techsupport/network engineer/IT manager who reports to a VP (who is the company's senior programmer). With that understanding in mind -- I never had to deal with designing a network using a core switch to edge switches to span two floors. We started out with hubs, then moved to straight switches over the years.

We are doing a *complete* renovation, for all practical purposes, the building (2 floors) will be completely new. Now my server center is going to be on the first floor where I plan to put my core switch. I am planning to need about 200 ports total on my edge switches, these will be located in a wiring closet in a centralized location on the *2nd floor*. The edge switches from this single closet will service all the network connections for the client machines on both floors.

Is this a sound plan? Should I have a separate wiring closet on each floor? What do you, as an expert in network design, suggest?

PS. For the core switch is fiber the top choice?


Re: Looking for advice on Core to Edge Switching Network Design

Seems kinda strange to have users on the first floor have cable to the second floor wiring closet then come back down again to the first floor where the core switch/servers are.

If possible, I would have two wiring closets (one per floor). If possible I would use fiber from the edge switches in the first and second floor wiring closets to the core switch in the server room.

My $.02

New Member

Re: Looking for advice on Core to Edge Switching Network Design

I agree.

Depending on your cable length (ethernet 100 meters) you may not be able to run all your station cables to the second floor. You might want to also do a server vlan and a vlan per floor.


Re: Looking for advice on Core to Edge Switching Network Design

Does it make sense to put your core switch in the central closet, and run fiber from there to your server room? Then you could install a server farm switch.

With the right equipment, you could terminate hundreds of 10/100 copper runs in a core switch chassis. You could even run all your servers directly back to the core switch if you wanted, patching in to 10/100/1000 ports or Gigabit fiber ports on the chassis. It would simplify troubleshooting.

Just remember your cable length restrictions: up to 90m radius of Cat5 or better in the horizontal, from station to closet. This leaves you 5m at each end of a run for patch cables; overall end-to-end length not to exceed 100m on any run, in order to stay compliant.

If you must keep servers and core switch in same 1st floor room for power, cooling, or security reasons, then I agree with the other posts here. Better to have at least two closets, one on each floor.

Standard practice is to have a main closet (MDF) per floor, and then fiber interconnects between floors. If your floors are big enough to need remote closets (IDFs), then the IDFs should connect back to the floor MDF using fiber. Your 1st floor server room would be an IDF, if you put a switch in there.

Getting businesses to reserve adequate space for xDFs or server rooms can be difficult, especially if it cuts into usable office space. So get your requests in early and often for space, cooling, and power. You'll never have enough.

You don't want to end up with a network like the following. I once worked for a company that had its original wiring closet on the 2nd floor; servers were up there too. Then a server room was created downstairs, and copper risers were put in place to tie the servers back in. Next, they started cabling 1st floor stations back to the 1st floor server room, turning it into a wiring closet. Tracing cabling problems was always an adventure: starting from the user's station location, the label on the jack would tell you which closet to check first. A trip to that closet would show whether the run actually ended there in a switch, or rode a riser cable to the other floor because all local switch ports were filled. There were 1st floor users plugged into switches on both floors, and 2nd floor users plugged into switches on both floors. It was a troubleshooting nightmare. I got lots of exercise there, because the documentation was never kept up-to-date.

Don't let this happen to you.

Hope this helps.

New Member

Re: Looking for advice on Core to Edge Switching Network Design

The Reply#3 is pretty much the perfect solution. Best of luck..



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