I assume I'm missing something important, as my datacenter knowledge is purely theoretical, but I always have taken the position that fiber is for connections where distance, interference, or physical density requirements either prohibit copper altogether or increase the costs enough to level the playing field. With that option out there, why bother with SFPs, fiber, or even DAC when you can just use good old twisted pair within the rack? If you've updated your rack patch cabling in the last few years it might already be 10G-capable, as plain Cat6 is in spec for up to 55 meters (Cat6a is required for full-length runs). What about 10GBaseT? A bit of googling indicates that it might have been hard to find equipment at some point, but all the names I cared to check (Cisco, Juniper, Intel, Broadcom) seem to offer it in NICs and switches these days. List price on those things runs about $1500 each. Why? Think about how much 10G-SR optics cost. When you're moving to 10G access, EoR becomes cost prohibitive. I like it a lot from a planning the network standpoint, but it's miserable for airflow, costs, and L2 everywhere initiatives. Every rack gets patch panels to a central area, and those get patched to the other side of the central area, and that patch panel finally terminates at a line card on a single switch. [For the record, my current data centers are even a step beyond EOR, and that's central cabling. I'm looking at chucking spanning tree and moving to FabricPath/Trill/whatever, and that'll let me feel somewhat more comfortable offering VLAN portability to any needed environment. This keeps the spanning tree loop out of the equation, gets ports near the servers, and minimizes the touch points, because the 2ks are managed via the 5ks. I've grown to live with the 2k/5k/7k solution, and just keep VLANs down a single 5k pair. I don't want VLANs spanned between switches, because spanning tree creep is a good way to take down a datacenter.Įven if you turn it into a pure 元 TOR environment, suddenly one ends up with hundreds of switches that need to get managed, and you have to create address space of exactly the right size on every single one of them. My only beef with TOR (or even EOR, for that matter) is that I'm really into 元 to the access, and I hate managing that many VLANs.

Eor vs tor switch