On Fri, 25 Jan 2008 20:30:20 -0500 "Ben Scott" <mailvortex@gmail.com> wrote:
On Jan 25, 2008 7:49 PM, Jim Popovitch <yahoo@jimpop.com> wrote:
I see the *exact* same problem with Comcast at home. I get about 30 seconds of the 6.6Mbps provisioned rate then the drop kicks in and down to 43kbps it goes.
I suspect this is just bursting/clamping, as you suspect, but you may also want to investigate traffic shaping at your end. I've found I get much better *receive* throughput if I limit my *transmit* rate to less than nominal maximum. Presumably, this has to do with the fact that the feed is asymmetric; I can receive much faster than I can send, and so the send channel becomes congested and that impacts TCP ACK or other protocol control messages.
For more details, "RFC3449 - TCP Performance Implications of Network Path Asymmetry" http://tools.ietf.org/rfc/rfc3449.txt Regards, Mark. -- "Sheep are slow and tasty, and therefore must remain constantly alert." - Bruce Schneier, "Beyond Fear"