leendert@cs.vu.nl (Leendert van Doorn) (12/15/88)
Hi Netlanders, Can anyone help me out with the following problem ? I'm trying to setup a uucp connection between two computers. One side runs nuucp (as distributed by NLUUG) the other runs a bare SIII uucp. When i make a connection (SIII uucp calls), the login process goes well, they agree about the protocol (g), and the SIII uucp becomes the master and starts transmitting. After six or more blocks the SIII side times out and sends an AYT (Are Y There) signal. The nuucp side doesn't ACK the AYT and after 16 tries the SIII uucp side breaks off the connection. Looking in the AUDIT files on the nuucp side, it shows that he also times out. However he recieved some of the message. Is my uucico broken ? Did i forget to set some parameters ? What can cause such a behaviour ? Thanks, Leendert -- Leendert P. van Doorn <leendert@cs.vu.nl> Vrije Universiteit / Dept. of Maths. & Comp. Sc. De Boelelaan 1081 1081 HV Amsterdam / The Netherlands tel. +31 20 548 5302
romain@pyrnj.uucp (Romain Kang) (12/24/88)
In article <1813@zell.cs.vu.nl> leendert@cs.vu.nl (Leendert van Doorn) writes: | I'm trying to setup a uucp connection between two computers. One side | runs nuucp (as distributed by NLUUG) the other runs a bare SIII uucp. | When i make a connection (SIII uucp calls), the login process goes well, | they agree about the protocol (g), and the SIII uucp becomes the master | and starts transmitting. After six or more blocks the SIII side times out | and sends an AYT (Are Y There) signal. The nuucp side doesn't ACK the AYT | and after 16 tries the SIII uucp side breaks off the connection. | | Looking in the AUDIT files on the nuucp side, it shows that he also | times out. However he recieved some of the message. You didn't mention how the two systems connect to each other. They could be wired directly to each other, use dialup modems, or use a high-speed network adaptor of some sort. It is common to see a configuration like hawk -- serial <--> network >==< FAST >==< network <--> serial -- raven line adaptor NETWORK adaptor line ("hawk" and "raven" are UNIX hosts running uucp of various flavors. FAST NETWORK might be an Ethernet, broadband, etc, and the network adaptors could be DEC LAT servers, Cisco boxes, etc.) The network adaptors may be using software flow control like XON/XOFF or ACK/NACK. Since the 'g' protocol uses its window size for flow control rather than special characters, XON, XOFF, et. al., could appear in the data stream without protection from the network flow control. Hence uucp packets stop flowing, and each side times out. For that matter, the FAST NETWORK could be the telephone network, and "network adaptors" could be dialup modems which again may be using XON/XOFF. It is possible that there is a broken uucico in there somewhere. However, flow control problems of this sort are the most common cause of uucp failure with unacknowledged protocol messages. -- "I am a teleological atheist, which is to say that I believe intelligent life exists, except in certain parts of New Jersey." --Woody Allen