Cable Forum - Well Done NTL

Quote:

Originally Posted by James Henry

BT's pricing of 8Mbit ADSL is no different per Mbit/s from their pricing of 2Mbit, ISPs undercharging is the issue.

Not so. BT used to charge a fixed amount for a 2Mb line with a fixed contention ratio (50:1 for home users). For 8Mb, they charge about 1.5M pounds per year for a 622Mb virtual pipe, and you can throw as many users as you like on it.

So, instead of fixing the contention ratio themselves, which when moving from 2Mb to 8Mb would mean they needed 4x as much capacity to maintain things, they just made ISPs deal with it.

Quote:

Originally Posted by James Henry

ntl's modems don't queue a thing, even if they did a router on your side would do nothing to affect the queues, would it? The modems are strictly FIFO and work as fast as they can, this is however controlled by congestion on the local network, if the modem can't get a slot in time and the buffer is filled the traffic is dumped.

This FIFO is the queue I'm talking about. Outgoing packets are delayed by having to wait in the FIFO.

A router can prevent this by only sending as many packets out per second as the modem can send. By having a constant, fixed speed stream of packets the modem never buffers them, it is always able to send strait away.

The advantage is that ping times are maintained. With pfsense, I can saturate 90% of my upstream bandwidth and still have a ping time of 30ms. Normally, anything over 20% of my upstream drops ping times instantly, and results in lost packets.