The issue was a network one, essentially a spike in the amount of network
traffic at a certain time caused an "overload" which in turn caused the
sessions to drop. The primary culprits appeared to be: NCP (novell
printing protocol of some sorts?), IPX (which should not have been
running at all) and multicast traffic (the app which runs in the call
center uses this to communicate to a server, which is a sun box).
Solution: eliminate IPX traffic altogether, find the cause of excessive
NCP traffic and work with 3pv to optimize the call center app. Nothing
iSeries related.
Thanks to everyone that pitched in with suggestions.
Uros