Communications error while trying to debug using service entry point

Hello everybody,

I am having a hard time trying to debug a program via Service Entry Point 
in WDSC
I am using WDSC 5.1.2.  Build id: 20040609_0820
The program to be debugged is on V5R3M0 and it is an interactive  program 
written in ILE RPG .
I have checked for required PTFs by using Verfiy Connection i WDSC - it 
seems we have all the PTFs.

While trying to start debugging I make the following steps
1. I click the right mouse button on  the pgm object to be debugged in 
Remote Systems Explorer and select
 "Service Entry Point -> Set"
2. iSeries Service Entry Points view opens showing my new SEP
3. I call my program (on iSeries) with the following result:
- in WDSC i get  an error message "Communications failure" displayed in a 
dialog box
- on iSeries I get "X System" displayed in the lowest row on the terminal 
(and it stays like that
until I do a "System Request -> End previous request")

4. if , after closing the dialog box with the message "Communications 
failure", I  trie to remove the service entry point
  it causes WDSC to hang (it displays a dialog box "Operation in progress" 
forever).

We have 2 iSeries boxes, and i have this problem on only one of them (on 
the other  debugging via SEPs works fine). 
What I should add is that there is a firewall between my workstation and 
the iSeries box that is giving me the trouble, 
but I checked and compared the TCP connections between my workstation and 
both iSeries boxes (to check if the firewall is not blocking any trafic).
The only difference is that there  are 2 connections from port 8472 on the 
"troublesome" iSeries to my workstation while there is
only one connection from port 8472 on the other iSeries box , to my 
workstation. 

Anybody has any  any ideas how to solve this  ?

Radek Pilski

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