Hi,
I have a question about monitoring ifq_ at a LAN. I modified the code in vlan.tcl so that it can monitor the ifq_, when I use 802_3 MAC at 100 source nodes.
The topology is as follows. Each source node will form a LAN with node 0, while node0 is using DRR to schedule the packets to node1. The traffic source are 50 UDP one-way flows from snode(i) to dnode(i) (0<=i<50)and 50 TCP one-way flows from snode(i) to dnode(i) (50<=i<100).
snode(0) dnode(0)
\ /
snode(1) --- node 0 ------node1---- node2 ----- dnode(1)
/ \
snode(99) dnode(99)
I could see the throughput decrease for both UDP and TCP dramatically, but I could see no drops in ifq_'s! This is extremely strange for UDP flows, because there will be no ACK's for UDP flows, which means no contention at all for UDP source. I am wondering if there are other places that LANs could possibly drop packets except ifq_? I also change the parameters for 802_3 to fit for 100Mbps Ethernet.
Please give me some suggestions. Thanks in advance!
Huiwen