Hello, I'm a relatively new user in NS-2, and I'm studying behavior on wireless MANETs (Mobile Ad-Hoc Networks). I'm using ns2-allinone-2.34 over Ubuntu 10.10 (kernel 2.6.35-25 generic). My issue is that I'm simulating two simple TCP scenarios over reactive protocols (AODV and DSR), but I'm having weird results in one of them. * The first scen has 2 TCP sources, one intermediate node, and 1 destination. http://old.nabble.com/file/p30924046/tcp_2fl_1dest.tcl tcp_2fl_1dest.tcl * The second one has 2 TCP sources, two intermediate nodes and two destinations. http://old.nabble.com/file/p30924046/tcp_2fl_2dest.tcl tcp_2fl_2dest.tcl
In the first scen both flows share simultaneously the bandwidth, but in the second one, flow seems to share the bandwidth alternatively (when one source sends the other one stops, and viceversa). I've tried with AODV and DSR, and this "issue" happens for both protocols. Besides, I've tried with UDP, and it doesn't happens (in both scen flows share bandwidth equitably), so I think it must be a TCP issue. Is this normal? Am I missing something? Maybe it is related with "hidden nodes"? But is looks weird to me, because in the first scen there is no problem. I've seen that occasionally there are packets dropped at MAC level. But, in fact, in the first scen (the one that works correctly), there are about 300 drops, meanwhile in the second one there are about 100. I'm getting crazy, because I don't know the reason of this behavior, and I'm not sure if it must be the "expected" behavior. Besides, I attach two graphics with the traffic sent by every node over the time, in order to show you what I mean. http://old.nabble.com/file/p30924046/throughput_2fl_1dest.png http://old.nabble.com/file/p30924046/throughput_2fl_2dest.png Thanks in advance and I would be really grateful if someone "illuminate" me. If you need further information don't hesitate to ask me. PS: sorry for my English, I'm not fluent and maybe this message has some mistakes. -- View this message in context: http://old.nabble.com/Issue-with-TCP-in-wireless-MANETs-scenarios-tp30924046p30924046.html Sent from the ns-users mailing list archive at Nabble.com.
