@1mthome wrote:
I usually download different *nix based OS (ISO image) for testing and scripting... Since I upgraded to ignite I've been getting file errors on all ISO image. I do understand there is no error correcting on the UDP protocol but I never had this much trouble getting a clean download, as anyone encountered this problem... ??
I can modify the TCP protocol (which has error correcting) on my end to download files but not widely accepted... Is it a server, modem hardware problem or modem software error...
Any help would greatly be appreciated
Actually, both TCP and UDP support error detection but neither support error correction (although TCP does perform error recovery).
TCP ensures that you have sequenced ordered delivery of datagrams. If a corrupted datagram is received, TCP will ACK with the last good sequence that was received, and the sender will retransmit any unacknowledged data after a timer expires.
With UDP, if the data checksum doesn't verify, the datagram and data will get dropped and it is up to the application to recover.
Some Unix systems allow you to disable verifying UDP checksums. (This was sometimes done to increase network performance in the old days, in particular to improve NFS throughput... but you risk data corruption if something on the network path trashes the UDP data, since the corruption would go undetected if the IP and packet headers were still intact.) I don't know of any modern systems that ship this way.
With UDP, it's technically possible that data in the UDP data field could get corrupted along the way, by any device with a bad memory module or a software bug that occasionally trashes in-memory copies, but any application that uses UDP should be coded to expect that datagrams will arrive out of order and that datagrams will occasionally get dropped.
I am guessing that you are using BitTorrent. Are the files that you download truncated or do they just fail the integrity checks?
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