nanog mailing list archives
Re: Latency, TCP ACKs and upload needs
From: Tony Finch <dot () dotat at>
Date: Wed, 20 Apr 2016 17:12:36 +0100
Leo Bicknell <bicknell () ufp org> wrote:
1460 byte payloads down, maybe 64 byte acks on the return, and with SACK which is widely deployed an ACK every 2-4 packets. You would see about 2,140 packets/sec downstream (25Mbps/1460), and perhaps send 1070 ACKs back upstream, at 64 bytes each, or about 68Kbps. Well under the 1Mbps upstream bandwidth.
Note that with delayed ACKs (RFC 1122) there is an ACK for every other packet; SACK should do better than that. Tony. -- f.anthony.n.finch <dot () dotat at> http://dotat.at/ - I xn--zr8h punycode Humber, Thames: Northwest, veering north or northeast, 4 or 5. Slight or moderate. Fair. Good.
Current thread:
- Latency, TCP ACKs and upload needs Jean-Francois Mezei (Apr 19)
- Re: Latency, TCP ACKs and upload needs Jared Mauch (Apr 19)
- Re: Latency, TCP ACKs and upload needs Eric Kuhnke (Apr 19)
- Re: Latency, TCP ACKs and upload needs joel jaeggli (Apr 19)
- Re: Latency, TCP ACKs and upload needs Eric Kuhnke (Apr 19)
- Re: Latency, TCP ACKs and upload needs Leo Bicknell (Apr 20)
- Re: Latency, TCP ACKs and upload needs Jean-Francois Mezei (Apr 20)
- Re: Latency, TCP ACKs and upload needs Lee (Apr 20)
- Re: Latency, TCP ACKs and upload needs Tony Finch (Apr 20)
- Re: Latency, TCP ACKs and upload needs Eygene Ryabinkin (Apr 21)
- Re: Latency, TCP ACKs and upload needs Chris Welti (Apr 24)
- Re: Latency, TCP ACKs and upload needs Lee (Apr 20)
- Re: Latency, TCP ACKs and upload needs Mikael Abrahamsson (Apr 20)