10GBASE-T versus 10GBASE-SR – Tradeoffs in Costs Make the Difference

By Lisa Huff

The 10GBASE-T standard was finalized some four years ago now, but, as I’ve mentioned before, equipment using these ports is really just starting to be deployed in actual networks. The main reason being that you couldn’t get a switch with these ports on it. So early implementations of 10G are 10GBASE-SR, 10GBASE-LR or 10GBASE-LRM, with the vast majority now being the SR. But now that switch manufacturers the likes of Blade Networks, Cisco (CSCO) and Extreme Networks (EXTR) have products offering up to 24 ports of 10GBASE-T, the market dynamics may change.

With Ethernet, history tends to repeat itself so let’s take a minute to review what happened at Gigabit. Early products were 1000BASE-CX, SX and LX because the 100m 1000BASE-T had not yet been standardized. But, as soon as it was and the switch manufacturers started adopting it, it took over the shorter-reach Gigabit Ethernet market. In fact, it still dominates today.

So, why would 10GBASE-T be any different? Well, my belief is that eventually, it won’t. Even though data center managers concerns have shifted from space, to power availability per rack and cooling hot spots, when they see the price tag difference between SR and T (still about 2:1 per installed port), it causes them to pause and rethink the T scenario. So although data center managers want to reduce their headaches with fat CAT6A cables, most are still not willing to pay that much more for the optical solution until they have to because of distances. So even though the T ports may push electricity bills up, for most, the increase isn’t significant enough to justify the up-front cost of SR.