From Neely on AS/400 Networking by Kris Neely, AS/400 Experts Journal, Vol. 3, No. 2, March/April 2000. Provided courtesy of The 400 Group
- Dump your twinax. Nothing slows overall network performance down more than 1-2 Mbps twinax. This is especially true if your company is competing in the minute-by-minute dog fight that is e-business technology.
- Don't mix batch and interactive programs in the same AS/400 subsystem. You'll murder your interactive performance.
- Lose your SNA-based Client Access package and make the move to Client Access Express -- the TCP/IP-only version of Client Access. In addition to less line traffic, you'll gain the ability to route your traffic better (read: speed).
- If you can, use an on-the-fly GUI product to put legacy applications on the Internet. Even green screen programs can outrun basic HTML/CGI if properly implemented.
- Scrap all network cabling that is not either Level (or Category) 5 Unshielded Twisted Pair (UTP) or, better yet, fiber.
- Optimize your RPG apps and DB2/400. At LAN speeds, a major burden is placed on your applications to maximize performance. Learn all you can about how to optimize your legacy RPG applications. Study everything you can lay your hands on about indexing, SQL Stored procedures, ILE program binding, and database normalization - each of these can subtract precious moments of computing time for your legacy applications or reduce network traffic.
- Review the block and frame sizes in your AS/400 communication descriptions -- the defaults as shipped by IBM are too small. Use the largest block and frame sizes your network can support, especially if you're only running an internal LAN. (Make sure your bridges or routers can handle the increased sizing.)
- Compress or "zip" your files before data transmission. This is especially true for spool file transfers.
- Run all communication lines as Full Duplex - even if you know you're "supposed" to be running only Half Duplex - trust me Full Duplex runs faster.
- Scrap bisync and SDLC communications in favor of TCP/IP.
This was first published in April 2000