4GL 4.11 frontend via network to 7.30 backend

Hi Informixers, from many discussions in this group and also from the manuals, I always got the information that 4.x and 5.x frontend products (like 4GL or ESQL/C) can only communicate with 7.x backends (like my brand- new IDS 7.30) via the performance-eating "relay module". For this reason, it was strongly advised to use at least 6.x frontends or the new 4GL/ISQL 7.20. I've asked the question before in this group, but received no answer: Is the above true also for socket connections via TCP/IP, or only for situations where frontend and backend run on the same machine? I just tested a 4GL 4.11 program running on one machine with I-Net 5.10 installed against another machine with IDS 7.30, connected via LAN and using TCP/IP. I was surprised that this worked instantly, and no relay module was used. Performance was not noticeably impaired. With "netstat", I could see a connection on the "sqlexec" port. Does this mean that the TCP/IP socket connection protocol has not changed between versions 4/5 and 6/7? Can I leave my appication server as it is and just upgrade the database server to 7.30 without suffering performance penalties? Of course I know that is beneficial to upgrade the frontends to the current versions, too (e.g. DBCENTURY), but this would increase the timeframe for the migration considerably. Regards, Richard -- +--------------------------+------------------------------------------+ | Dr. Richard Spitz | INTERNET: spitz@ana.med.uni-muenchen.de | | EDV-Gruppe Anaesthesie | Tel : +49-89-7095-3413 | | Klinikum Grosshadern | FAX : +49-89-7095-8886 | | 81366 Munich, Germany | GSM : +49-172-8933578 | +--------------------------+------------------------------------------+