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Larry, >On a token-ring you can go as high as 16393. If you have systems >communicating on a local ring these huge packets can really boost throughput >for >large file transfers (including spool files). They won't affect things like >Telent a whit. Where can I find documentation on the interrelationships of the max frame size of the LIND, the MTU of the interface, and all the rest of the stuff related to datagram size etc? I tried the OS/400 TCP/IP Configuration and Reference manual, and it didn't have much to say, at least in my V3R7 copy. Haven't checked the V4 copies on the web. Last weekend I was experimenting on trying to increase the throughput of my local TR network (no routers) and had mixed success. I was able to boost transfers from my 400 to the PC to run at about 950K/sec, but can only achieve half of that when transferring from my PC to the 400. I surmise it is a problem with packet sizes, but can't figure out the magic combinations. Here's the best throughput I've got yet: AS/400: - 2619 adapter; 16M line speed; *HALF duplex - 16393 max frame size; early token release set to *YES - Interface set to *NORMAL type of service, MTU of *LIND - Interface shows a MTU of 16388 while active PC's: - IBM PCI Auto LanStreamer adapters - Max TX frame size set to 8156 (16393 didn't work!) - Receive buffer size set to 16388 Connected via passive MSAU (a SMC Elite 4016RN) Obviously the PC's max frame size of 8156 could explain why I get much lower throughput on PC to 400 then 400 to PC. But when I set the PC to 16388 or 16393, I can't even ping the 400 let alone transfer anything. The PC driver lets me specify the TX frame size but not the MTU, so I had figured 16393 would be the value to use. The driver lets me enter any arbitrary value I want (not just select from a list of values). When I couldn't get 16393 or 16388 to work, I went down to 8156 because it is the next lower value listed by the 400 help text for a "suggested" TR frame size. I also tried setting the 400 interface type of service to *MAXTHRPUT instead of *NORMAL, but again couldn't ping between the systems until I went back to *NORMAL. Any ideas? I'd like to get my upload speeds to match the 950K/sec I can now get with downloads. There are only 5 devices on my network: two AS/400's, two PC's, and a HP JetDirect. Doug +--- | This is the Midrange System Mailing List! | To submit a new message, send your mail to MIDRANGE-L@midrange.com. | To subscribe to this list send email to MIDRANGE-L-SUB@midrange.com. | To unsubscribe from this list send email to MIDRANGE-L-UNSUB@midrange.com. | Questions should be directed to the list owner/operator: david@midrange.com +---
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