Two Tips for better ISA Performance
via Amy's:
https://isainsbs.blogspot.com/2005/10/from-jim-harrison-add-this-to-your-isa.html
Short version:
1. Changing the NetBIOS node type to p-node (point-to-point name resolution only).
2. Changing the MTU (ISA Server 2004 sets a 576 MTU by default).