On Friday 25 April 2003 02:50, Saikrishna Dasari wrote:

Hi friends, I have been using UDPCast successfully for the fast few months and it was successful. in most cases. But recently when I was trying to clone a 5.5 GB Partion from one machine to other machine ( of same architecture..both are dell machines, both have 256 MB RAM, Identical HDD geometry, Identical NICs).

on the sender side after getting a few retransmission messages it kept on saying that

nrBlocks=36 lastGoodBlock=0nrBlocks=130 Timeout notAnswered=[0] notReady=[0] nrAns=0 nrRead=0 nrPart=1 avg=3969 bytes=1 232 425 333 re-xmits=001037 (0.0%) slice=0036 1 232 425 333 and reciever doesn't give any messages.

It looks as if for some reason, the communication between sender and receiver has been cut completely. Maybe some switch getting confused with the udpcast's multicast packets? We had once a case where a 3com switch would block all traffic for 30 seconds, then open up again, and let them pass for another 30 seconds..., and then close again. So every 30 seconds, we would get a flurry of such messages. UDPcast did cope, although the transfer did obviously twice as long as it otherwise would have...

Could you check whether devices of two different speeds are connected to the switch (such as 100 Mbps computers, and maybe a 10 Mbps printer?). Try disconnecting all 10 Mbps devices, and check whether the problem still occurs.

what does this message mean. Does it assure us a safe transfer ..if not how to rectify this problem.Any help is highly appreciated.

Thanks, Sai

Udpcast does produce a safe transfer: if packets are dropped, they are retransmitted. However, if the retransmissions also fail, udpcast will eventually consider that receiver as dead, and "drop it" from the list of receivers in order to be able to continue with those receivers that do not suffer from the problem.

Alain