iRule for persistence table entries

You would actually have to collect the data first with TCP::collect before the CLIENT_DATA event is triggered, then you'd have to figure out how to extract the username in each case. Something like this:

   
   when CLIENT_ACCEPTED {   
       collect enough data to see the username string in either case   
      TCP::collect 1024   
   }   
   when CLIENT_DATA {   
       extract the username value from [TCP::payload], using whatever    
       string anchors are available to mark then end & beginning of the username   
      set username ...  [TCP::payload]...??? 
       then persist on it   
      persist uie $username 1800   
      TCP::release   
   }  

Not sure what the RDP login sequence looks like, but if the server talks first, you will have to write a more complex proxy iRule. If the data is binary or otherwise encoded, you will have to account for that as well. The SMTP Proxy iRule in the codeshare (Click here) might prove helpful if you have to pursue either of those options.

hth

/deb