Hi Everyone,

I have a requirement to send large tar packets in half duplex (one way only communication). I'm trying to determine what is the best values and to use in udp-sender and udp-receiver.

My setup is, one server connected to another across a single 1Gb fibre link (no return path). The tar packets are sometimes very large, in the Gb's and I can't have any loss.

My first setting were:-

On the sending server:-

udp-sender --async --log /tmp/log --fec 8x6/64 --max-bitrate 100m --autostart 1 --mcast-data-addr 224.2.2.2 --interface eth0 -f /root/send`date +%y%m%d%H%M`.tar

There is a crontab to run this udp-sender line every 10 minutes to keep sending new packets.

On the receiving server:-

udp-receiver --interface eth0 --file /root/send`date +%y%m%d%H%M`.tar

There is a crontab to run a script checking if udp-receiver is running and if not restarts it so it's ready for the next packet.

I initially started the -max-bitrate at 1000m and it actually successfully got a tar packet across but after repetitive testing found it was dropping packets halfway through the transfer. So I continued to decrease the -max-bitrate. It got progressively better until I got to a bitrate of 100m. Then I found that the receiving server would start to receive the packet then dropped it straight away leaving a 0 byte size packet or occasionally a very small file (e.g 8Mb), which from observation I found it was dropping it almost instantly.

I currently have a test running over the weekend with a couple of changed settings in the udp-sender:-

udp-sender --async --log /tmp/log --fec 8x8/128 --max-bitrate 100m --autostart 3 --mcast-data-addr 224.2.2.2 --interface eth0 -f /root/send`date +%y%m%d%H%M`.tar

I increased the fec in hope that it would improve the transfer speed and increased the autostart hoping it would help in not dropping out at the beginning of a reception.

Could you please let me know your thoughts?

Also if there are any things you think I should add or change in the udp-sender or udp-receiver to improve the reliability and transfer speed. For my requirements I really need to have a fasted transfer rate (and thought I'd get better than 100Mb on a 1Gb link) and I certainly can't go any slowed. I also require a zero loss performance.

Thanks,

Markus