[Click] Packet loss with PollDevice
Yu Chen
yuchen at cs.duke.edu
Thu Jan 19 13:45:00 EST 2012
Hi all,
I am having an experiment with the following topology running on Deterlab. I
am having a 4-core Xeon and modified e1000 driver running ore Xeon and modified
e1000 driver running. The memory is 4GB.
User1
|
User3-----Router------User4
|
User2
User 1 is sending packet to User 2; User 3 is sending packets to User 4.
The router only routes stuff with best effort. However, what I observed is
very few losses, distributed on a small random set of rounds. What is
surprising is that there are losses on one particular netcard when the sending
rate is only 125,000 packets/second. The loss happens at the receiving phase.
Below is what I have tried:
1' I am using 4 threads, each corresponding to one pair of PollDevice and
ToDevice.
2' I have changed the queue length at the interface cards. I set txqueuelen=1
for the senders to decrease the possible burstiness. By increasing the
receiving queue length from 64 to 4096
(the maximum queue length), the loss rate decreases.
3' I tried to discard the packets on their arrival at the router. In this case,
there is no observed loss.
I am kind of lost at the point. Any suggestions on what can be the possible
reason and what I can try next?
Attached is my code.
Best Regards,
Yu
Router:
-----------------------------------------------------------------------
ddressInfo(router1-w1 10.0.1.1 00:15:17:5d:16:4a, //eth2
user1-w1 10.0.1.2 00:15:17:5d:29:28, //eth0
router1-w2 10.0.2.1 00:15:17:5d:16:48, //eth0
user2-w2 10.0.2.2 00:15:17:57:ce:14, //eth0
router1-w3 10.0.3.1 00:15:17:5d:16:4b, //eth3
user3-w3 10.0.3.2 00:15:17:5d:27:e8, //eth0
router1-w4 10.0.4.1 00:15:17:5d:16:49, //eth1
user4-w4 10.0.4.2 00:15:17:5d:2a:3c, //eth0
);
c1 :: Classifier(12/0806 20/0001,
12/0806 20/0002,
12/0800,
-);
c2 :: Classifier(12/0806 20/0001,
12/0806 20/0002,
12/0800,
-);
c3 :: Classifier(12/0806 20/0001,
12/0806 20/0002,
12/0800,
-);
c4 :: Classifier(12/0806 20/0001,
12/0806 20/0002,
12/0800,
-);
q0 :: Discard;
// Idle -> ToDevice(eth1);
// Idle -> ToDevice(eth3);
// Idle -> ToDevice(eth2);
// Idle -> ToDevice(eth0);
q1 :: CPUQueue(1000000) -> EtherEncap(0x0800, router1-w1, user1-w1) -> td1 :: ToDevice(eth2);
q2 :: CPUQueue(1000000) -> EtherEncap(0x0800, router1-w2, user2-w2) -> td3 :: ToDevice(eth0);
q3 :: CPUQueue(1000000) -> EtherEncap(0x0800, router1-w3, user3-w3) -> td2 :: ToDevice(eth3);
q4 :: CPUQueue(1000000) -> EtherEncap(0x0800, router1-w4, user4-w4) -> td0 :: ToDevice(eth1);
rt :: LookupIPRouteMP(10.0.1.0/32 0, 10.0.1.1/32 0, 10.0.1.255/32 0,
10.0.2.0/32 0, 10.0.2.1/32 0, 10.0.2.255/32 0,
10.0.3.0/32 0, 10.0.3.1/32 0, 10.0.3.255/32 0,
10.0.4.0/32 0, 10.0.4.1/32 0, 10.0.4.255/32 0,
10.0.1.0/24 1, 10.0.2.0/24 2, 10.0.3.0/24 3,
10.0.4.0/24 4, 0.0.0.0/0 0);
rt[0] -> Discard;
rt[1] -> q1;
rt[2] -> q2;
rt[3] -> q3;
rt[4] -> q4;
pd1 :: PollDevice(eth2) -> c1;
c1[0] -> q0;
c1[1] -> q0;
c1[2] -> DropBroadcasts -> Strip(14) -> GetIPAddress(16) -> rt;
c1[3] -> Discard;
pd3 :: PollDevice(eth0) -> c2;
c2[0] -> q0;
c2[1] -> q0;
c2[2] -> DropBroadcasts -> Strip(14) -> GetIPAddress(16) -> rt;
c2[3] -> Discard;
pd2 :: PollDevice(eth3) -> c3;
c3[0] -> q0;
c3[1] -> q0;
c3[2] -> DropBroadcasts -> Strip(14) -> GetIPAddress(16) -> rt;
c3[3] -> Discard;
pd0 :: PollDevice(eth1) -> c4;
c4[0] -> q0;
c4[1] -> q0;
c4[2] -> DropBroadcasts -> Strip(14) -> GetIPAddress(16) -> rt;
c4[3] -> Discard;
StaticThreadSched(pd2 0, td0 0, pd0 1, td2 1, pd3 2, td1 2, pd1 3, td3 3);
User:
//
AddressInfo(router1-w1 10.0.1.1 00:15:17:5d:16:4a, //eth2
user1-w1 10.0.1.2 00:15:17:5d:29:28, //eth0
router1-w2 10.0.2.1 00:15:17:5d:16:48, //eth0
user2-w2 10.0.2.2 00:15:17:57:ce:14, //eth0
router1-w3 10.0.3.1 00:15:17:5d:16:4b, //eth3
user3-w3 10.0.3.2 00:15:17:5d:27:e8, //eth0
router1-w4 10.0.4.1 00:15:17:5d:16:49, //eth1
user4-w4 10.0.4.2 00:15:17:5d:2a:3c, //eth0
);
//Send
udp :: FastUDPSource(RATE 400000, LIMIT 20000000, LENGTH 78,
SRCETH user1-w1, SRCIP user1-w1, SPORT 1,
DSTETH router1-w1, DSTIP user2-w2, DPORT 1,
CHECKSUM false, INTERVAL 0, ACTIVE false)
-> ToDevice(eth0);
s :: Script(TYPE ACTIVE, write ctr.reset, write udp.active false,
wait 1, wait 9, write udp.active true);
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