Hi everyone... I developed a perl program to calculate end-to-end delay from my ns-2 trace file. Oddly enough, I got fatal error "Illiegal division by zero". At first I though that I got error in my program. However when I check my trace file, I found that the sent time and received for data packets (both CBR and Exponential) are the same. Below is a portion of my trace file:
exponential traffic, GPSR s 0.823902776 _3_ AGT --- 244 exp 250 [0 0 0 0] ------- [3:0 15:0 32 0] r 0.823902776 _3_ RTR --- 244 exp 250 [0 0 0 0] ------- [3:0 15:0 32 0] D 0.823902776 _3_ RTR SBF 139 exp 297 [0 0 0 0] ------- [3:0 15:0 128 0] s 0.827809026 _3_ AGT --- 245 exp 250 [0 0 0 0] ------- [3:0 15:0 32 0] r 0.827809026 _3_ RTR --- 245 exp 250 [0 0 0 0] ------- [3:0 15:0 32 0] D 0.827809026 _3_ RTR SBF 140 exp 297 [0 0 0 0] ------- [3:0 15:0 128 0] CBR traffic, GPSR s 2.060625000 _3_ AGT --- 1032 cbr 210 [0 0 0 0] ------- [3:0 15:0 32 0] [628] 0 0 r 2.060625000 _3_ RTR --- 1032 cbr 210 [0 0 0 0] ------- [3:0 15:0 32 0] [628] 0 0 D 2.060625000 _3_ RTR SBF 931 cbr 257 [0 0 0 0] ------- [3:0 15:0 128 0] [564] 0 0 s 2.063783723 _52_ RTR --- 1033 GPSR 1 [0 0 0 0] ------- [52:255 -1:255 32 0] 3 0 [-1 -1] s 2.063808723 _52_ MAC --- 1033 GPSR 29 [0 ffffffff 34 0] ------- [52:255 -1:255 32 0] 3 0 [-1 -1] s 2.063906250 _3_ AGT --- 1034 cbr 210 [0 0 0 0] ------- [3:0 15:0 32 0] [629] 0 0 r 2.063906250 _3_ RTR --- 1034 cbr 210 [0 0 0 0] ------- [3:0 15:0 32 0] [629] 0 0 CBR traffic, AODV s 0.200156250 _3_ AGT --- 61 cbr 210 [0 0 0 0] ------- [3:0 15:0 32 0] [61] 0 0 r 0.200156250 _3_ RTR --- 61 cbr 210 [0 0 0 0] ------- [3:0 15:0 32 0] [61] 0 0 s 0.203437500 _3_ AGT --- 62 cbr 210 [0 0 0 0] ------- [3:0 15:0 32 0] [62] 0 0 r 0.203437500 _3_ RTR --- 62 cbr 210 [0 0 0 0] ------- [3:0 15:0 32 0] [62] 0 0 s 0.206718750 _3_ AGT --- 63 cbr 210 [0 0 0 0] ------- [3:0 15:0 32 0] [63] 0 0 r 0.206718750 _3_ RTR --- 63 cbr 210 [0 0 0 0] ------- [3:0 15:0 32 0] [63] 0 0 s 0.210000000 _3_ AGT --- 64 cbr 210 [0 0 0 0] ------- [3:0 15:0 32 0] [64] 0 0 r 0.210000000 _3_ RTR --- 64 cbr 210 [0 0 0 0] ------- [3:0 15:0 32 0] [64] 0 0 As you can see in each portion of my trace, for the same flow id, the data packets are sent and received at the same time. I even use AODV protocol just to make sure, but I still got the same type of result. With this kind of trace, I definitely cannot calculate the delay because basically there is no delay. Is my trace correct or did I make mistakes in my tcl program? Have anyone encounter the same issue as I did? By the way, my scenario is 95 mobile nodes simulated in vehicular ad hoc network environment with speed 20 m/s. Thank you in advance regards Aslinda Hassan Computer Engineering Research Lab Faculty of Engineering and Applied Science Memorial University of Newfoundland
