Ok I will do these tests tomorrow. On Wed, Apr 22, 2009 at 9:30 PM, Michael Blizek <michi1@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hi! > > On 10:56 Wed 22 Apr , Devesh Sharma wrote: >> On Tue, Apr 21, 2009 at 9:48 PM, Michael Blizek >> <michi1@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote: >> > Hi! >> > >> > On 18:37 Tue 21 Apr , Devesh Sharma wrote: >> >> Hello michi, Sorry for late reply. comments are inline: > > ... > >> >> > "ping -f -s 4096" say? How much does the latency increase if you send >> >> > bigger packets? Is there a "magic value" which causes a "sudden increase" >> >> > (e.g. 4051 is much slower than 4050)? >> >> Yes there is a magic number for packet size of 4040 bytes in ping -s >> >> 4040 gives proper results >> >> but of ping -s 4041 every alternate packet get delayed upto 1000 ms. > >> > IP header is 20 byte >> > UDP header is 8 byte (what prococol are you using?) >> >> I am using TCP not UDP > > OK. > > ... > >> I have also checked with my device debugging tool, it posting exactly >> 2 descriptors each of 2048 size for every 4040 byte ping packet, so >> for (4096-4040) = 56 additional bytes. > > This sounds interesting. Can you install a sniffer and see what is going on: > - There should be 3 data packets for 4041 byte packets > - Are these 3 packets sent at once or is the 3rd packet delayed until an ack > is received? > - Is the ack received fast or is there some delay? If a data packet has the > push flag set, there should not be any delay beyond the normal network > latency. > - Are there any retransmissions? > > netstat -s may also have some hints. > > Can you send the values of these files in /proc/sys/net/ipv4/ ? > > tcp_congestion_control > tcp_reordering > tcp_rmem > tcp_wmem > > >> I am also not able to receive jeffrey's posts!! > > Have you subscribed the list? jeffrey sent his mails only to the list and has > not put you in to or cc while most others have. If you are not subscribed, you > can still send to the list and see replies where people have put you in to or > cc. > > -Michi > -- > programing a layer 3+4 network protocol for mesh networks > see http://michaelblizek.twilightparadox.com > > -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
