After a storm of CRC errors from UHUPVM1 (RSCS V2.3), I removed that server from the backbone a few days ago to see whether the problem was actually there (in which case errors should stop coming in) or elsewhere. The errors first stopped flowing in, but today a new storm of even worse proportions originated from TAMVM1 (RSCS V1!), so I have removed it as well to see what happens. This is probably due to the usual RSCS bugs in processing multiple dataset header files. There are different flavours of bugs for RSCS V1 and V2.3, there are probably fixes but I wouldn't know the APAR numbers. RSCS V1 tends to insert garbage in the file, while buggy levels of V2.3 latter happily decide that the transfer has successfully completed after writing a couple lines to the punch, and move on to the next file. For instance, two BITNET nodes have been chronically unable to receive any file destined to both nodes for about one and a half year now (both have been informed several times and neither has time to deal with this problem). As long as this only affects end nodes it really isn't my problem, but I have to make sure that the backbone works. My plans are to wait a few days and then try putting UHUPVM1 back under the assumption that the problem was at TAMVM1. Eric