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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical RE: FW: ISPs slowing P2P traffic...
Except that upstreams are not at 27 Mbps (http://i.cmpnet.com/commsdesign/csd/2002/jun02/imedia-fig1.gif show that you would be using 32 QAM at 6.4 MHz). The majority of MSOs are at 16-QAM at 3.2 MHz, which is about 10 Mbps. We just took over two systems that were at QPSK at 3.2 Mbps, which is about 5 Mbps. And upstreams are usually sized not to be more than 250 users per upstream port. So that would be a 10:1 oversubscription on upstream, not too bad, by my reckoning. The 1000 you are thinking of is probably 1000 users per downstream power, and there is a usually a 1:4 to 1:6 ratio of downstream to upstream ports. Frank -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Mikael Abrahamsson Sent: Tuesday, January 15, 2008 5:41 PM To: [email protected] Subject: RE: FW: ISPs slowing P2P traffic... On Tue, 15 Jan 2008, Frank Bulk wrote: > I'm not aware of MSOs configuring their upstreams to attain rates for 9 and > 27 Mbps for version 1 and 2, respectively. The numbers you quote are the > theoretical max, not the deployed values. But with 1000 users on a segment, don't these share the 27 megabit/s for v2, even though they are configured to only be able to use 384kilobit/s peak individually? -- Mikael Abrahamsson email: [email protected]
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