A few week ago, I was stuck with my perl script to do post-simulation using NS-2. I though I need to understand the trace format. After read the ns-Manual and some literature, so, here is interpretation of NS-2 trace format for wireless simulation.
wireless simulation, you’d better read the code of ns2 in file ns2home/trace/cmu-trace{.h, .cc}Mostly, the format would be as
ACTION: [s|r|D]: s -- sent, r -- received, D -- dropped
WHEN: the time when the action happened
WHERE: the node where the action happened
LAYER: AGT -- application,
RTR -- routing,
LL -- link layer (ARP is done here)
IFQ -- outgoing packet queue (between link and mac layer)
MAC -- mac,
PHY -- physical
flags:
SEQNO: the sequence number of the packet
TYPE: the packet type
cbr -- CBR data stream packet
DSR -- DSR routing packet (control packet generated by routing)
RTS -- RTS packet generated by MAC 802.11
ARP -- link layer ARP packet
SIZE: the size of packet at current layer, when packet goes down, size increases, goes up size decreases
[a b c d]: a -- the packet duration in mac layer header
b -- the mac address of destination
c -- the mac address of source
d -- the mac type of the packet body
flags:
[......]: [
source node ip : port_number
destination node ip (-1 means broadcast) : port_number
ip header ttl
ip of next hop (0 means node 0 or broadcast)
]
So we can interpret the below trace
s 76.000000000 _98_ AGT --- 1812 cbr 32 [0 0 0 0] ------- [98:0 0:0 32 0]
as
Application 0 (port number) on node 98 sent a CBR packet whose ID is 1812 and size is 32 bytes, at time 76.0 second, to application 0 on node 0 with TTL is 32 hops. The next hop is not decided yet.
And we can also interpret the below trace
r 0.010176954 _9_ RTR --- 1 gpsr 29 [0 ffffffff 8 800] ------- [8:255 -1:255 32 0]
in the same way, as
The routing agent on node 9 received a GPSR broadcast (mac address 0xff, and ip address is -1, either of them means broadcast) routing packet
whose ID is 1 and size is 19 bytes, at time 0.010176954 second, from node 8 (both mac and ip addresses are 8), port 255 (routing agent).
