Well, prior to CAT they had OATS, which has been around for a very long time, but was only "top level" messages (not a deep trace into the stack). If you combi

Well, prior to CAT they had OATS, which has been around for a very long time, but was only "top level" messages (not a deep trace into the stack). If you combine crosses with OATS you can still get some of the data you are looking for, just not as cleanly as with CAT.