The cable I'm most interested in from this point of view is one that run's to the backup system in the garage so I can look at the statistics over a few days of backups to see if there's anything wrong.
Couldn't you just calculate the md5 checksums and compare? The odd missed packet here and there isn't usually a big deal in the bigger picture, right? TCP recovers from packet loss so it's a bit of a non-issue as long as the data is getting from A to B.
-Simon