what is "tcp window size" ? thank you
The TCP header has a 16 bits field that specifies (and now I''m quoting from the RFC 793): "The number of data octets beginning with the one indicated in the acknowledgment field which the sender of this segment is willing to accept." In plain english: how much "useful" data you can accept from the sender.> what is "tcp window size" ? > > thank you__________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Thank you very much... What values are recommended for diferent situations ? for a Vsat link ? ADSL ? LAN ? ... and so on... is important to set this value on linux ? If you have a URL to get more information, please post it . thanks again... andres. -> -> -> The TCP header has a 16 bits field that specifies (and now -> I''m quoting from the RFC 793): "The number of data octets -> beginning with the one indicated in the acknowledgment -> field which the sender of this segment is willing to -> accept." In plain english: how much "useful" data you can -> accept from the sender. -> -> > what is "tcp window size" ? -> > -> > thank you -> -> -> __________________________________________________ -> Do You Yahoo!? -> Tired of spam? Yahoo! Mail has the best spam protection around -> http://mail.yahoo.com -> _______________________________________________ -> LARTC mailing list -> LARTC@mailman.ds9a.nl -> http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
Querying google for "tcp window size" returns some links. I don''t know the recommended values and I don''t know either if you can play with this value in linux, or if it is wise. There is built-in flow control in the TCP protocol and it adjusts the window size according to your available bandwidth. Obviously, the bigger, the better, but if more data arrives than can be accepted, it will be discarded and retransmission will be necessary. On the other side, if the window is set too small, the same information is transmitted using more segments when maybe it could be transmitted using fewer segments.> Thank you very much... > > What values are recommended for diferent situations ? > > for a Vsat link ? ADSL ? LAN ? ... and so on... > > is important to set this value on linux ? > > If you have a URL to get more information, please post > it . > > thanks again... > > andres. > > > -> > -> > -> The TCP header has a 16 bits field that specifies (and > now > -> I''m quoting from the RFC 793): "The number of data > octets > -> beginning with the one indicated in the acknowledgment > -> field which the sender of this segment is willing to > -> accept." In plain english: how much "useful" data you > can > -> accept from the sender. > -> > -> > what is "tcp window size" ? > -> > > -> > thank you > -> > -> > -> __________________________________________________ > -> Do You Yahoo!? > -> Tired of spam? Yahoo! Mail has the best spam > protection around > -> http://mail.yahoo.com > -> _______________________________________________ > -> LARTC mailing list > -> LARTC@mailman.ds9a.nl > -> http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc > _______________________________________________ > LARTC mailing list > LARTC@mailman.ds9a.nl > http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc >____________________________________________________ Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs
On Sun, 2005-07-31 at 05:42 -0700, Gabriel wrote:> Querying google for "tcp window size" returns some links. I > don''t know the recommended values and I don''t know either > if you can play with this value in linux,AFAIK, this value isn''t something which QoS can handle or dynamically change. This is based on my research I did some 6-8 months ago. Though things may have changed during that time.> or if it is wise. > There is built-in flow control in the TCP protocol and it > adjusts the window size according to your available > bandwidth. Obviously, the bigger, the better, but if more > data arrives than can be accepted, it will be discarded and > retransmission will be necessary. On the other side, if the > window is set too small, the same information is > transmitted using more segments when maybe it could be > transmitted using fewer segments.Yes, one of the reasons for the need for dynamic scaling of the window sizes is to do reduce the retranmissions and thus the dropping of packets because they arrive too fast. In an ideal world, this shouldn''t happen and links shouldn''t get saturated with unneeded packets and dropping it at the gateway/router etc and hence losing bandwidth. AFAICT, TCP''s built in window scaling just moves it up each time it gets a successful transmit, but when it drops, it will have to restart itself say, from zero. That''s my uderstanding. May be flawed.>-- Ow Mun Heng Gentoo/Linux on DELL D600 1.4Ghz 1.5GB RAM 98% Microsoft(tm) Free!! Neuromancer 12:14:36 up 8 days, 18:26, 5 users, load average: 0.15, 0.22, 0.24
hi, On Sat, 2005-07-30 at 21:38 -0300, :: L i n u XK i D :: wrote:> Thank you very much... > > What values are recommended for diferent situations ? > > for a Vsat link ? ADSL ? LAN ? ... and so on...For a vsat link, it depends on who''s indoor unit your using -- if you''re running behind a Gilat/Satlynx 360E or a Eutelsat (built by Viasat) then all layer 4 parameters are stripped off and set by the satellite modem. therefore, you don''t need to play with window size because it''s ignored. see Thomas Ross Henderson''s masters thesis for a more in depth look at satellites. Cheers Charles