We are currently set up with EP 6.0 SP2 running on WebAS 6.20. This is connected to an R/3 Enterprise 470x200 running on 6.20. It has become apparent that we need to quickly get our Enterprise Portal upgraded so it runs on WebAS 6.40. But we do not want to upgrade the R/3 WebAS servers. First of all, can you even do this? Have EP 6.0 on WebAS 6.40 connected to R/3 on WebAs 6.20? If you can, has anyone done it? If so, have there been any major issues? In theory this should work just fine, but I am concerned that BAPI calls from Portal apps to the R/3 back end may run into some issues.
Any information is greatly appreciated!