Hi Eric,
It's probable that T supports a special OC-48 Ring at 2.5 Gb/s for @Home (actually, I now recall that T claimed to be running dual OC-48s at one point, or the equivalent of 5 Gb/s) "through" most cities where @Home's larger nodes reside, but not "to" every node.
Stated another way, they don't necessarily serve every node with that much capacity, or "terminate" an entire OC-48 worth of b/w in each node.
They couldn't, if you think about it. If they did drop the whole OC-48 load, say, at the first city node in the ring, then they wouldn't have anything to drop off at the second and additional sites around the ring. This assumes that the MSO nodes are getting dedicated upstream pipes towards the core of the Home network, of course.
It's not quite as simple as I've just described, because routers and upstream mesh conditions get into the act, so it's not as linear as I've made it appear. But it serves our purposes here.
The OC-48 (which equates to 48 T3s plus SONET signalling overhead) is a backbone ring from which individual T3s, or groups of T3s (for example, an OC-3, or even possibly an OC-12 at the largest or special purpose sites) could be dropped and inserted along the way.
I suspect that there are more sites doing quite well using T3s or OC3s than one would normally suspect, given that T made so much ado over their OC-48 rings a while back. FWIW.
FAC |
