[112771] in North American Network Operators' Group
Re: Shady areas of TCP window autotuning?
daemon@ATHENA.MIT.EDU (Lars Eggert)
Tue Mar 17 19:47:17 2009
From: Lars Eggert <lars.eggert@nokia.com>
To: Tony Finch <dot@dotat.at>
In-Reply-To: <alpine.LSU.2.00.0903171909240.8701@hermes-2.csi.cam.ac.uk>
Date: Tue, 17 Mar 2009 16:46:28 -0700
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
--Apple-Mail-81--819133213
Content-Type: text/plain;
charset=US-ASCII;
format=flowed;
delsp=yes
Content-Transfer-Encoding: 7bit
On 2009-3-17, at 12:10, Tony Finch wrote:
> On Tue, 17 Mar 2009, Joe Maimon wrote:
>>
>>> TCP needs drops to manage to the right speed.
>>
>> This is whats bad. TCP should be slightly more intelligent and start
>> considering rtt jitter as its primary source of congestion
>> information.
>
> TCP Vegas did this but sadly it never became popular.
> (It doesn't compete well with Reno.)
FWIW, Compound TCP does this (shipping with Vista, but disabled by
default.) There are other delay-based or delay-sensitive TCP flavors,
too.
Lars
--Apple-Mail-81--819133213
Content-Disposition: attachment;
filename=smime.p7s
Content-Type: application/pkcs7-signature;
name=smime.p7s
Content-Transfer-Encoding: base64
MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIGQDCCAvkw
ggJioAMCAQICEEi7WbMMKa2GLKFpQDaOBQEwDQYJKoZIhvcNAQEFBQAwYjELMAkGA1UEBhMCWkEx
JTAjBgNVBAoTHFRoYXd0ZSBDb25zdWx0aW5nIChQdHkpIEx0ZC4xLDAqBgNVBAMTI1RoYXd0ZSBQ
ZXJzb25hbCBGcmVlbWFpbCBJc3N1aW5nIENBMB4XDTA4MDgyMzE3NDMzOVoXDTA5MDgyMzE3NDMz
OVowXDEPMA0GA1UEBBMGRWdnZXJ0MQ0wCwYDVQQqEwRMYXJzMRQwEgYDVQQDEwtMYXJzIEVnZ2Vy
dDEkMCIGCSqGSIb3DQEJARYVbGFycy5lZ2dlcnRAbm9raWEuY29tMIIBIjANBgkqhkiG9w0BAQEF
AAOCAQ8AMIIBCgKCAQEAlwQVktJZCY89iU6jcW1XnZQN+aMgF2utCUT3H3ZKB5Jbet1SDWt0md/W
571bHjxtn9CfEJdochNL3l9f1WiJNdVbJ182557Ltx9SojqthpqtA0jKEqo2gqrf+raUj1demmo0
6ocsLqv046CrwidOp6k0RAfvkKPLhD4PD9Nk3oaZuxqBz1wY4u8Q83iWMArDeXiQxfNZnOBz5cDs
VvVjTjitm3VANkbD02tNkwl5AHw7htde4yH8hIwlfzqsAtHBEah3HyOvs9b+gHg2pFz9eS+HuotY
ZKycCweRs8NKXoCg+zAkVYi3zvZEH2VOuPlpMQMrB9+fLWg2UBsTeZ864wIDAQABozIwMDAgBgNV
HREEGTAXgRVsYXJzLmVnZ2VydEBub2tpYS5jb20wDAYDVR0TAQH/BAIwADANBgkqhkiG9w0BAQUF
AAOBgQBMdV2U+ryV5t3nuBFH19XKflodN6Bc60GBYHHY/Z0+Cl08Q75qzTt02IILBg+/YVh/fygb
6pFrOm1sFtLN7fENBfbO2VtpFjP2lGUgbXTVT5xGM6+MtqZiBI6LqexAeY6gsd/taoUfy9fZG42d
ciBA9gSGlQjjWQyG8mb5HR8L9jCCAz8wggKooAMCAQICAQ0wDQYJKoZIhvcNAQEFBQAwgdExCzAJ
BgNVBAYTAlpBMRUwEwYDVQQIEwxXZXN0ZXJuIENhcGUxEjAQBgNVBAcTCUNhcGUgVG93bjEaMBgG
A1UEChMRVGhhd3RlIENvbnN1bHRpbmcxKDAmBgNVBAsTH0NlcnRpZmljYXRpb24gU2VydmljZXMg
RGl2aXNpb24xJDAiBgNVBAMTG1RoYXd0ZSBQZXJzb25hbCBGcmVlbWFpbCBDQTErMCkGCSqGSIb3
DQEJARYccGVyc29uYWwtZnJlZW1haWxAdGhhd3RlLmNvbTAeFw0wMzA3MTcwMDAwMDBaFw0xMzA3
MTYyMzU5NTlaMGIxCzAJBgNVBAYTAlpBMSUwIwYDVQQKExxUaGF3dGUgQ29uc3VsdGluZyAoUHR5
KSBMdGQuMSwwKgYDVQQDEyNUaGF3dGUgUGVyc29uYWwgRnJlZW1haWwgSXNzdWluZyBDQTCBnzAN
BgkqhkiG9w0BAQEFAAOBjQAwgYkCgYEAxKY8VXNV+065yplaHmjAdQRwnd/p/6Me7L3N9VvyGna9
fww6YfK/Uc4B1OVQCjDXAmNaLIkVcI7dyfArhVqqP3FWy688Cwfn8R+RNiQqE88r1fOCdz0Dviv+
uxg+B79AgAJk16emu59l0cUqVIUPSAR/p7bRPGEEQB5kGXJgt/sCAwEAAaOBlDCBkTASBgNVHRMB
Af8ECDAGAQH/AgEAMEMGA1UdHwQ8MDowOKA2oDSGMmh0dHA6Ly9jcmwudGhhd3RlLmNvbS9UaGF3
dGVQZXJzb25hbEZyZWVtYWlsQ0EuY3JsMAsGA1UdDwQEAwIBBjApBgNVHREEIjAgpB4wHDEaMBgG
A1UEAxMRUHJpdmF0ZUxhYmVsMi0xMzgwDQYJKoZIhvcNAQEFBQADgYEASIzRUIPqCy7MDaNmrGcP
f6+svsIXoUOWlJ1/TCG4+DYfqi2fNi/A9BxQIJNwPP2t4WFiw9k6GX6EsZkbAMUaC4J0niVQlGLH
2ydxVyWN3amcOY6MIE9lX5Xa9/eH1sYITq726jTlEBpbNU1341YheILcIRk13iSx0x1G/11fZU8x
ggMQMIIDDAIBATB2MGIxCzAJBgNVBAYTAlpBMSUwIwYDVQQKExxUaGF3dGUgQ29uc3VsdGluZyAo
UHR5KSBMdGQuMSwwKgYDVQQDEyNUaGF3dGUgUGVyc29uYWwgRnJlZW1haWwgSXNzdWluZyBDQQIQ
SLtZswwprYYsoWlANo4FATAJBgUrDgMCGgUAoIIBbzAYBgkqhkiG9w0BCQMxCwYJKoZIhvcNAQcB
MBwGCSqGSIb3DQEJBTEPFw0wOTAzMTcyMzQ2MjhaMCMGCSqGSIb3DQEJBDEWBBQSgx7FjPQ0xJSm
WjIaRAvRwETTeDCBhQYJKwYBBAGCNxAEMXgwdjBiMQswCQYDVQQGEwJaQTElMCMGA1UEChMcVGhh
d3RlIENvbnN1bHRpbmcgKFB0eSkgTHRkLjEsMCoGA1UEAxMjVGhhd3RlIFBlcnNvbmFsIEZyZWVt
YWlsIElzc3VpbmcgQ0ECEEi7WbMMKa2GLKFpQDaOBQEwgYcGCyqGSIb3DQEJEAILMXigdjBiMQsw
CQYDVQQGEwJaQTElMCMGA1UEChMcVGhhd3RlIENvbnN1bHRpbmcgKFB0eSkgTHRkLjEsMCoGA1UE
AxMjVGhhd3RlIFBlcnNvbmFsIEZyZWVtYWlsIElzc3VpbmcgQ0ECEEi7WbMMKa2GLKFpQDaOBQEw
DQYJKoZIhvcNAQEBBQAEggEAVC3rrFTtOtI6gccDLhHmlcxcRkMXqARp6roopbUx9BR373kZXGPv
w5bTP1XAoPfcUl4U9MHJa4x9nMIm0GRb+UaITX29SH7guWLMoIRWXfx1oa5BYHSwwjIyyq5hJMOZ
5g5L9ij3uQAgF00xGeIhTGMPT4enkw3B2RAogIiJyPDxbH+ogKNO/7nbz8O3V7RWLMEAJ4uQZ414
X1BKrMhEwiyYsaQuFeMSrjBvq9IMwVVgOY4C6NAstlhA+0Tnu6eQPz5aptqYNr1nAUg9KFtXLNB/
1lcGiyAawQF3iZSib9Yi0URp1dKm52qBB7O/kz/mfLEX3C725T6mfQS89hDOIAAAAAAAAA==
--Apple-Mail-81--819133213--
