LCA: Vint Cerf on re-engineering the Internet [LWN.net]

LCA: Vint Cerf on re-engineering the Internet

Posted Jan 26, 2011 3:02 UTC (Wed) by jthill (guest, #56558)
In reply to: LCA: Vint Cerf on re-engineering the Internet by mtaht
Parent article: LCA: Vint Cerf on re-engineering the Internet

But isn't the uplink the advice is for a gigabit uplink, not 3Mb? If that's right, I make the uplink latency for a full ath9k queue well under 10ms - they should be able to run flat out. That or I borked the math.

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LCA: Vint Cerf on re-engineering the Internet

Posted Jan 26, 2011 4:11 UTC (Wed) by mtaht (✭ supporter ✭, #11087) [Link]

In the case of a wireless card in your laptop or a wireless link you can be running at speeds ranging from 300Mbit down to 1Mbit/sec, or less.

In the case of a home gateway, my comcast's business class service is running at about 3Mbit/sec on the uplink.

Huge dark (unmanaged) buffers in the device affect latency really badly - not just for TCP/ip, but for stuff that would ordinary jump to the head of the queue - udp, dns, voip, gaming, NTP... ... and in some cases are so big as to break TCP/ip almost entirely.

We've been sizing device buffers as if it was all on gigE backbone networks. Nor have we been using reasonable AQM. I urge you to try the experiments mentioned earlier.