Cable Forum - View Single Post

Chrysalis · 20-12-2012, 13:41

cable can do more than what VM achieve, the issue is they have too many customers per node and as such performance is poor.

eg. VM could bond 4 QAM64 US channels instead of 1 QAM16 US channel and halve the modems connected to that service group at the same time and you would probably see even with say 20mbit upload much lower network jitter/congestion. It still would have the issue Qas said of modems not able to send data at the same time as each other but with less modems per node it becomes less of an issue.

Part of the problem is the tech but I think the biggest part of the problem is how VM have chose to sell the service.

The openreach FTTC infrastructure could have potentially had much higher contention ratio than it has now but openreach chose to build it the way they did so the chance of congestion on the local access network is remote, but there is still contention on the dsl signal on openreach FTTC services so crosstalk drops attainable speeds as well as contention on backhaul and peering/transit etc. so both technologies have their own downsides.

20-12-2012, 13:41	#16
Chrysalis cf.mega poster Join Date: Sep 2003 Posts: 12,047	Re: Virgin Media Network Quality cable can do more than what VM achieve, the issue is they have too many customers per node and as such performance is poor. eg. VM could bond 4 QAM64 US channels instead of 1 QAM16 US channel and halve the modems connected to that service group at the same time and you would probably see even with say 20mbit upload much lower network jitter/congestion. It still would have the issue Qas said of modems not able to send data at the same time as each other but with less modems per node it becomes less of an issue. Part of the problem is the tech but I think the biggest part of the problem is how VM have chose to sell the service. The openreach FTTC infrastructure could have potentially had much higher contention ratio than it has now but openreach chose to build it the way they did so the chance of congestion on the local access network is remote, but there is still contention on the dsl signal on openreach FTTC services so crosstalk drops attainable speeds as well as contention on backhaul and peering/transit etc. so both technologies have their own downsides.