Date: Thu, 7 Sep 1995 22:59:05 -0700 From: Stephen Melvin <melvin@zytek.com> To: freebsd-hackers@freebsd.org Subject: Patch to User Mode PPP Code (or... Six Echos or Separation) Message-ID: <199509080559.WAA02519@syzygy.zytek.com>
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Hello,
I applied the patch shown below to /usr/src/usr.sbin/ppp/lqr.c. It turns
out that ppp was hanging up on my customers a couple of minutes into a long
file download and I tracked it to the logic which disconnects when it
thinks that echo requests are not being returned. For some reason during
these long file transfers the replies were exactly 6 echos behind (i.e. 3
minutes) and the logic in lqr.c cuts off at 5. I don't know why the echos
were delayed 3 minutes, but all the while I'm getting maximum throughput;
at the other end I'm running Trumpet Winsock under Windows 3.1. In any
case, I changed the numbers to 10 and I've had no trouble since. I have
verified that even during longer downloads (2.1Mb) the 6 echos of
separation remains. Note that a limit of 10 will mean a 5 minute delay
(instead of 2.5 minutes) if the other end dies completly. Below I have
also attached a sample of the LQR output from the log file. Regards,
Stephen Melvin
melvin@zytek.com
--------
Appendix A -- LQR log, 587K byte transfer over 14.4K modem
09-07 21:22:44 [1919] LQM method = 3
09-07 21:22:44 [1919] LqrOutput:
09-07 21:22:44 [1919] Magic: 3393bf54 LastOutLQRs: 00000000
09-07 21:22:44 [1919] LastOutPackets: 00000000 LastOutOctets: 00000000
09-07 21:22:44 [1919] PeerInLQRs: 00000000 PeerInPackets: 00000012
09-07 21:22:44 [1919] PeerInDiscards: 00000000 PeerInErrors: 00000000
09-07 21:22:44 [1919] PeerInOctets: 00000247 PeerOutLQRs: 00000003
09-07 21:22:44 [1919] PeerOutPackets: 0000000f PeerOutOctets: 000001e4
09-07 21:22:44 [1919] Will send LQR every 30.0 secs
09-07 21:22:44 [1919] StopLqr method = 1
09-07 21:22:44 [1919] Stop sending LQR, Use LCP ECHO instead.
09-07 21:22:44 [1919] Send echo LQR [1]
09-07 21:22:44 [1919] Got echo LQR [1]
09-07 21:23:14 [1919] Send echo LQR [2]
09-07 21:23:14 [1919] Got echo LQR [2]
09-07 21:23:44 [1919] Send echo LQR [3]
09-07 21:23:44 [1919] Got echo LQR [3]
Note: data transfer started here
09-07 21:24:14 [1919] Send echo LQR [4]
09-07 21:24:44 [1919] Send echo LQR [5]
09-07 21:25:14 [1919] Send echo LQR [6]
09-07 21:25:44 [1919] Send echo LQR [7]
09-07 21:26:14 [1919] Send echo LQR [8]
09-07 21:26:29 [1919] Got echo LQR [4]
09-07 21:26:29 [1919] Got echo LQR [5]
09-07 21:26:44 [1919] Send echo LQR [9]
09-07 21:27:14 [1919] Send echo LQR [10]
09-07 21:27:44 [1919] ** Too many ECHO packets are lost. **
09-07 21:27:44 [1919] Send echo LQR [11]
09-07 21:27:46 [1919] Got echo LQR [6]
09-07 21:28:14 [1919] ** Too many ECHO packets are lost. **
09-07 21:28:14 [1919] Send echo LQR [12]
09-07 21:28:16 [1919] Got echo LQR [7]
09-07 21:28:44 [1919] ** Too many ECHO packets are lost. **
09-07 21:28:44 [1919] Send echo LQR [13]
09-07 21:28:46 [1919] Got echo LQR [8]
09-07 21:29:14 [1919] ** Too many ECHO packets are lost. **
09-07 21:29:14 [1919] Send echo LQR [14]
09-07 21:29:16 [1919] Got echo LQR [9]
09-07 21:29:44 [1919] ** Too many ECHO packets are lost. **
09-07 21:29:44 [1919] Send echo LQR [15]
09-07 21:29:46 [1919] Got echo LQR [10]
09-07 21:30:14 [1919] ** Too many ECHO packets are lost. **
09-07 21:30:14 [1919] Send echo LQR [16]
09-07 21:30:16 [1919] Got echo LQR [11]
09-07 21:30:44 [1919] ** Too many ECHO packets are lost. **
09-07 21:30:44 [1919] Send echo LQR [17]
09-07 21:30:46 [1919] Got echo LQR [12]
Note: data transfer ended here
09-07 21:30:51 [1919] Got echo LQR [13]
09-07 21:30:52 [1919] Got echo LQR [14]
09-07 21:30:52 [1919] Got echo LQR [15]
09-07 21:30:52 [1919] Got echo LQR [16]
09-07 21:30:52 [1919] Got echo LQR [17]
09-07 21:31:14 [1919] Send echo LQR [18]
09-07 21:31:14 [1919] Got echo LQR [18]
--------
Appendix B -- lqr.c patch
*** lqr.c Thu Sep 7 21:49:54 1995
--- lqr.c.orig Thu Sep 7 21:48:49 1995
***************
*** 116,122 ****
lqrsendcnt++;
}
} else if (lqmmethod & LQM_ECHO) {
! if (echoseq - gotseq > 10) {
LogPrintf(LOG_PHASE, "** Too many ECHO packets are lost. **\n");
LcpClose();
Cleanup(EX_ERRDEAD);
--- 116,122 ----
lqrsendcnt++;
}
} else if (lqmmethod & LQM_ECHO) {
! if (echoseq - gotseq > 5) {
LogPrintf(LOG_PHASE, "** Too many ECHO packets are lost. **\n");
LcpClose();
Cleanup(EX_ERRDEAD);
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