Dear list members,
I'm interested in the best case performance of UDPcast on fast networks like Fast Ethernet or Gigabit Ethernet. So far my results are not so good, but maybe I'm doing something wrong and maybe somebody can give me any hints.
For Fast Ethernet, I get the following performance (without disk access):
Clients Performance [MB/s] re-xmits 1 11.8 12 2 0.89 142290 4 0.93 103320 8 1.0 ?
So, while I get wire speed with only one client and server, I only get about 10% of the best performance for more than 1 client. Am I missing something? Are the high re-xmit-numbers normal or do they point to a problem? The commands I use are as follows:
node01:~/src/udpcast> ./udp-sender --file /dev/zero --full-duplex node02:~/src/udpcast> ./udp-receiver --file /dev/null
On Gigabit Ethernet the performance seems even worse, I can barely transmit any data. Here's what happens on the sender during 1 minute:
node01:~/src/udpcast> time ./udp-sender --file /dev/zero --full-duplex --interface eth1 --log /tmp/udpcast.log Udp-sender 2001-12-31 172.25.1.101 Using mcast address 236.25.1.101 UDP sender for /dev/zero at 172.25.1.101 172.25.1.101 on eth1 Broadcasting control to 172.25.255.255 New connection from 172.25.1.102 (#0) 00000019 Ready. Press any key to start sending data.
Starting transfer: 00000019 bytes= 163 072 re-xmits=000000 ( 0.0%) slice=0112 - 0 Received retransmittal request for 1 from 0: Retransmitting 1.41 Retransmitting 1.42 Retransmitting 1.43 Retransmitting 1.90 [CTRL-C] 0.000u 0.000s 1:06.53 0.0%mits=00+0k 0+0io 138pf+0we=0112 - 0
And on the receiver: node02:~/src/udpcast> time ./udp-receiver --file /dev/null --interface eth1 --log /tmp/udpcast.log Udp-receiver 2001-12-31 UDP receiver for /dev/null at 172.25.1.102 172.25.1.102 on eth1 received message, cap=00000019 Connected as #0 to 172.25.1.101 172.25.1.102 Listening to multicast on 236.25.1.101 Press any key to start receiving data! bytes= 326 144 ( 0.29 Mbps) Cancelled by user 0.000u 0.020s 1:15.49 0.0% 0+0k 0+0io 140pf+0w
Any ideas?
Regards, Felix