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- Xref: sparky comp.mail.uucp:1658 comp.dcom.modems:12057 biz.comp.telebit:817
- Path: sparky!uunet!zephyr.ens.tek.com!gvgpsa!ssigv!sunrise!gdonl
- From: gdonl@sunrise.ssi1.com (Don Lewis)
- Newsgroups: comp.mail.uucp,comp.dcom.modems,biz.comp.telebit
- Subject: Re: TB+ and uucp spoofing - does it really work
- Keywords: spurious spoofing?
- Message-ID: <1992Aug14.085224.13787@ssigv.UUCP>
- Date: 14 Aug 92 08:52:24 GMT
- References: <BsMwFp.op@wsrcc.com> <1992Aug8.130855.8889@terminator.cc.umich.edu> <5102@airs.com>
- Sender: news@ssigv.UUCP
- Organization: Silicon Systems, Nevada City CA
- Lines: 641
- Nntp-Posting-Host: sunrise
-
- In article <5102@airs.com> ian@airs.com (Ian Lance Taylor) writes:
- >honey@citi.umich.edu (Peter Honeyman) writes:
- >
- >>i've heard rumors of bugs creeping into later versions
- >>of spoofing modems, but the assertion that the originial spoofing modems
- >>worked flawlessly is borne out by years of experience with tens of thousands
- >>of units in the field.
- >
- >I believe that bugs must have crept in. I've seen several debugging
- >traces in which a Trailblazer modem has broken the protocol, always
- >following an unexpected event such as a corrupted packet or (in one
- >case) a bad assumption in my code which lead to a missed time out.
- >One person (who I won't mention here, since he may not want the
- >publicity) even put a protocol analyzer on the line and proved that
- >the modem was definitely at fault. He has sent the information to
- >Telebit, but I don't know if they have responded.
-
- I guess this my cue to speak up. First a bit of background though.
- I've got a Sparc 2 running SunOS 4.1.1, and a T2500 with ROM version
- GF7.00. For quite a while I've been having problems with dropped
- uucp connections to both my local news feed (an Ultrix box with BA5.00
- TB+'s) and uunet. The visible symptoms were that while receiving a
- file, the receive data light on the modem would go dark, the send
- light would blink a few times, and then the connection would be dropped.
- I thought that the BNU uucp supplied with the Sun might be buggy, and
- since I had been hearing good things about Taylor uucp, I decided to
- switch. Unfortunately, my problems with dropped connections continued.
- The problem seems to be sporadic. Sometimes, days go by without error.
- On other days, 20 percent of my calls fail. I finally got disgusted, so
- I cranked up the log level on uucico and took a look.
-
- The uucp logs seemed to indicate that the modem was violating the
- uucp 'g' protocol. I sent a copy of one of the logs and other relevant
- information to Telebit tech support. The response that I received
- indicated that they suspected that the problem was that the Sun was
- dropping characters, especially since the Sun doesn't support RTS/CTS
- flow control on incoming data. I responded that it didn't seem this
- was likely, since there was no correlation with system load, I didn't
- receive any diagnostics (like Silo overflow), in raw mode the kernal
- input buffer should hold at least 256 characters which is more than
- a g(3,64) window, and cranking up the log level of uucico on the Sun
- (the receiving end!) seemed to make the problem occur less frequently
- instead of more so. In any case, the 'g' protocol should be able to
- recover from dropped characters. I also sent Telebit some more logs
- that showed the modem sending other nonsense packets, such as acks for
- packets that were sent ages ago and acks for packets that hadn't been
- sent. I finally hooked up a protocol analyzer and it showed that the
- uucico logs were accurate. I mailed this information off to Telebit,
- and have yet to receive a response.
-
- >These problems have never led to corrupted data, to my knowledge,
- >since the modem usually drops the connection not too long after the
- >errors start to occur (but when I implement file restart, the chance
- >of data corruption will increase).
-
- See the attached log if you really want to be scared.
-
- >If you want to run a Telebit in spoofing mode, I recommend ensuring
- >that you have an essentially error free connection between the modem
- >and the computer; for a particularly slow or a particularly fast
- >computer, this will require hardware handshaking, or running at a baud
- >rate less than 9600.
-
- Unfortunately, it looks like the session can go off into the weeds
- even without errors on the connection between the modem and the computer.
-
- Ok, here is a log from uucico from a failed connection. Up until this
- point, everything was working fine. The modem was doing the correct 'g'
- protocol thing. The computer was loaded, so sometimes its acks were
- delayed, but the modem would always pause once it had three outstanding
- packets, until at least one of them was ack'ed. At about this point in
- the connection, things started to go out to lunch, although it is not
- visible in the uucico log, but it is visible in the trace from the protocol
- analyzer. At the end of the log, just before the connection is dropped,
- the problems become visible. After the log is an annotated RS232 trace.
-
- root gvgpsa (8/4-22:11:44,12436,0) DEBUG: fgsend_control: Sending control RR 1
- root gvgpsa (8/4-22:11:44,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 8812
- root gvgpsa (8/4-22:11:44,12436,0) DEBUG: fgwait_for_packet: Need 46 bytes
- root gvgpsa (8/4-22:11:44,12436,0) DEBUG: fport_read: Read 114
- root gvgpsa (8/4-22:11:44,12436,0) DEBUG: fgprocess_data: Got packet 2
- root gvgpsa (8/4-22:11:44,12436,0) DEBUG: fgsend_control: Sending control RR 2
- root gvgpsa (8/4-22:11:44,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 8698
- root gvgpsa (8/4-22:11:44,12436,0) DEBUG: fgwait_for_packet: Need 2 bytes
- root gvgpsa (8/4-22:11:44,12436,0) DEBUG: fport_read: Read 21
- root gvgpsa (8/4-22:11:44,12436,0) DEBUG: fgprocess_data: Got packet 3
- root gvgpsa (8/4-22:11:44,12436,0) DEBUG: fgsend_control: Sending control RR 3
- root gvgpsa (8/4-22:11:44,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 8677
- root gvgpsa (8/4-22:11:44,12436,0) DEBUG: fgwait_for_packet: Need 51 bytes
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_read: Read 196
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgprocess_data: Got packet 4
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgsend_control: Sending control RR 4
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 8481
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgprocess_data: Got packet 5
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgsend_control: Sending control RR 5
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 8481
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgprocess_data: Got packet 6
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgsend_control: Sending control RR 6
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 14 of 8481
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgwait_for_packet: Need 51 bytes
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_read: Read 144
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgprocess_data: Got packet 7
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgsend_control: Sending control RR 7
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 8323
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgprocess_data: Got packet 0
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgsend_control: Sending control RR 0
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 8323
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgwait_for_packet: Need 47 bytes
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_read: Read 162
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgprocess_data: Got packet 1
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgsend_control: Sending control RR 1
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 8161
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgprocess_data: Got packet 2
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgsend_control: Sending control RR 2
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 8161
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgwait_for_packet: Need 25 bytes
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_read: Read 56
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgprocess_data: Got packet 3
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgsend_control: Sending control RR 3
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 8105
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgwait_for_packet: Need 39 bytes
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_read: Read 154
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgprocess_data: Got packet 4
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgsend_control: Sending control RR 4
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7951
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgprocess_data: Got packet 5
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgsend_control: Sending control RR 5
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7951
- root gvgpsa (8/4-22:11:45,12436,0) DEBUG: fgwait_for_packet: Need 25 bytes
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_read: Read 54
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgprocess_data: Got packet 6
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgsend_control: Sending control RR 6
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7897
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgwait_for_packet: Need 41 bytes
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_read: Read 50
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgprocess_data: Got packet 7
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgsend_control: Sending control RR 7
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7847
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgwait_for_packet: Need 61 bytes
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_read: Read 64
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgprocess_data: Got packet 0
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgsend_control: Sending control RR 0
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7783
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgwait_for_packet: Need 3 bytes
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_read: Read 26
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgwait_for_packet: Need 41 bytes
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_read: Read 65
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgprocess_data: Got packet 1
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgsend_control: Sending control RR 1
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7692
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgwait_for_packet: Need 46 bytes
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_read: Read 172
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgprocess_data: Got packet 2
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgsend_control: Sending control RR 2
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7520
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgprocess_data: Got packet 3
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgsend_control: Sending control RR 3
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7520
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgwait_for_packet: Need 14 bytes
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_read: Read 37
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgprocess_data: Got packet 4
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgsend_control: Sending control RR 4
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7483
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgwait_for_packet: Need 47 bytes
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_read: Read 118
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgprocess_data: Got packet 5
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgsend_control: Sending control RR 5
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7365
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgprocess_data: Got packet 6
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgsend_control: Sending control RR 6
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7365
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgwait_for_packet: Need 5 bytes
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_read: Read 38
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgwait_for_packet: Need 31 bytes
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_read: Read 75
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgprocess_data: Got packet 7
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgsend_control: Sending control RR 7
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7252
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgwait_for_packet: Need 26 bytes
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_read: Read 108
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgprocess_data: Got packet 0
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgsend_control: Sending control RR 0
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7144
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgprocess_data: Got packet 1
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgsend_control: Sending control RR 1
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7144
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgwait_for_packet: Need 58 bytes
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_read: Read 58
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgprocess_data: Got packet 2
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgsend_control: Sending control RR 2
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 7086
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgwait_for_packet: Need 6 bytes
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fport_read: Read 10
- root gvgpsa (8/4-22:11:46,12436,0) DEBUG: fgwait_for_packet: Need 6 bytes
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fport_read: Read 112
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fgprocess_data: Got packet 1; expected 3
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fgwait_for_packet: Need 32 bytes
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fport_read: Read 116
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fgprocess_data: Got packet 2; expected 3
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fgprocess_data: Got packet 3
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fgsend_control: Sending control RR 3
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 6848
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fgwait_for_packet: Need 6 bytes
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fport_read: Read 56
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fgwait_for_packet: Need 14 bytes
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fport_read: Read 114
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fgprocess_data: Got packet 1; expected 4
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fgprocess_data: Got packet 2; expected 4
- root gvgpsa (8/4-22:11:47,12436,0) DEBUG: fgwait_for_packet: Need 44 bytes
- root gvgpsa (8/4-22:11:48,12436,0) DEBUG: fport_read: Read 46
- root gvgpsa (8/4-22:11:48,12436,0) DEBUG: fgprocess_data: Got packet 3; expected 4
- root gvgpsa (8/4-22:11:48,12436,0) DEBUG: fgwait_for_packet: Need 6 bytes
- root gvgpsa (8/4-22:11:58,12436,0) DEBUG: fport_read: Read 0
- root gvgpsa (8/4-22:11:58,12436,0) DEBUG: fgsend_control: Sending control RJ 3
- root gvgpsa (8/4-22:11:58,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 6632
- root gvgpsa (8/4-22:11:58,12436,0) DEBUG: fgwait_for_packet: Need 6 bytes
- root gvgpsa (8/4-22:12:08,12436,0) DEBUG: fport_read: Read 0
- root gvgpsa (8/4-22:12:08,12436,0) DEBUG: fgsend_control: Sending control RJ 3
- root gvgpsa (8/4-22:12:08,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 6632
- root gvgpsa (8/4-22:12:08,12436,0) DEBUG: fgwait_for_packet: Need 6 bytes
- root gvgpsa (8/4-22:12:18,12436,0) DEBUG: fport_read: Read 0
- root gvgpsa (8/4-22:12:18,12436,0) DEBUG: fgsend_control: Sending control RJ 3
- root gvgpsa (8/4-22:12:18,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 6632
- root gvgpsa (8/4-22:12:18,12436,0) DEBUG: fgwait_for_packet: Need 6 bytes
- root gvgpsa (8/4-22:12:28,12436,0) DEBUG: fport_read: Read 0
- root gvgpsa (8/4-22:12:28,12436,0) DEBUG: fgsend_control: Sending control RJ 3
- root gvgpsa (8/4-22:12:28,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 6632
- root gvgpsa (8/4-22:12:28,12436,0) DEBUG: fgwait_for_packet: Need 6 bytes
- root gvgpsa (8/4-22:12:38,12436,0) DEBUG: fport_read: Read 0
- root gvgpsa (8/4-22:12:38,12436,0) DEBUG: fgsend_control: Sending control RJ 3
- root gvgpsa (8/4-22:12:38,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 6632
- root gvgpsa (8/4-22:12:38,12436,0) DEBUG: fgwait_for_packet: Need 6 bytes
- root gvgpsa (8/4-22:12:48,12436,0) DEBUG: fport_read: Read 0
- root gvgpsa (8/4-22:12:48,12436,0) DEBUG: fgsend_control: Sending control RJ 3
- root gvgpsa (8/4-22:12:48,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 6632
- root gvgpsa (8/4-22:12:48,12436,0) DEBUG: fgwait_for_packet: Need 6 bytes
- root gvgpsa (8/4-22:12:58,12436,0) DEBUG: fport_read: Read 0
- root gvgpsa (8/4-22:12:58,12436,0) ERROR: Timed out waiting for packet
- uucp gvgpsa (8/4-22:12:58,12436,0) DEBUG: fgsend_control: Sending control CLOSE 0
- uucp gvgpsa (8/4-22:12:58,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 6632
- uucp gvgpsa (8/4-22:12:58,12436,0) DEBUG: fgsend_control: Sending control CLOSE 0
- uucp gvgpsa (8/4-22:12:58,12436,0) DEBUG: fport_io: Wrote 6 of 6, read 0 of 6632
- uucp gvgpsa (8/4-22:12:58,12436,0) Protocol 'g' packets: sent 2, resent 0, received 131
- uucp gvgpsa (8/4-22:12:58,12436,0) Errors: header 0, checksum 0, order 5, remote rejects 0
- uucp gvgpsa (8/4-22:12:58,12436,0) DEBUG: fport_write: Writing 8
- uucp gvgpsa (8/4-22:12:58,12436,0) DEBUG: fport_write: Writing 8
- uucp gvgpsa (8/4-22:12:58,12436,0) Call complete (89 seconds)
- uucp gvgpsa (8/4-22:12:58,12436,0) DEBUG: fcall_failed: Cause 5 (Call failed)
- uucp gvgpsa (8/4-22:12:58,12436,0) DEBUG: fport_close: Closing port
-
-
- Here is the trace from the protocol analyzer, the data from the modem is
- on the lines labeled with '*' and is below the simultaneous data from
- the computer:
-
-
- ] **** HP 4957 Printer Output ****
- ]
- ]
- ] Block 18 Print Page 42
- ] 108A20
- ] 099A1B
- ] 556A33A9BAA1134880042C844759736F*
- ] A628937BCDE376339B4B5012632A9893*
- ^ send RR 1
- ]
- ] E5904457E8102299E9FF5E4361805A91*
- ] 56C153024F0253AE4182EE8817B43221*
- ^ start of packet 3
- ]
- ] A7AC67A34A40C00433B8A5922745E0F9*
- ] 4F9B38F289B23744DD9ACEBC7ABEA0B6*
- ] 108
- ] 098
- ] D2E7A31EA0011E2810E1A5C802C9C06D*
- ] FA6D3C5764D00284020121491D085BF2*
- ^ send rr2
- ^ start of packet 4
- ] A20 108A20
- ] A29 097A37
- ] 2E8D334E0382B091152DAC6BE4BC4842*
- ] FA391E809419040F58E57C8A820C9D38*
- ^ send rr3
- ]
- ] 54F09520AC963640B0290A1010AB8139*
- ] B094E175C0A93F68801048023CA70389*
- ^ start of packet 5
- ]
- ] Block 19 Print Page 43
- ]
- ] 72D04585E24051F5DB8D036C244E6003*
- ] DA8CCD45C4F8E13948C92667C0704613*
- ]
- ] 866E8104A4CCA252D6F3E8071B1610FF*
- ] 3686AC2806ACE9DA052227C09B5C022A*
- ^ start of packet 6
- ]
- ] BB6E4D076A2246AECBB0487F379251BD*
- ] 28E619254CC3221AFC0DCDFD5C2C3758*
- ]
- ] 288F000732AEB9480A8CC31AE799374C*
- ] 898FC5C43D61C877CA0598B73CC032AE*
- ] 108A20108A20108A2
- ] 096A41095A53094A6
- ] C310C1B63168328D02C2B3ACE208305C*
- ] 990273AC994347B39CE708902C2B372E*
- ^ start of packet 7
- ^ send rr4
- ^ send rr5
- ^send rr6
-
- Ok, here is the first problem. We've received and ack'ed packet 3.
- The modem has sent packets 4, 5, and 6, which have not yet been ack'ed.
- The modem starts sending packet 7, but this is outside our window of
- three packets that we negotiated at the beginning of the session.
- The computer manages to read all the packets anyway.
-
- ] 0
- ] 1
- ] D434AEE04EE48B29922126014A2C7207*
- ] 19AB79CBF0C8460C864C010C5B361C7C*
- ]
- ] Block 19 Print Page 44
- ]
- ] 16F24E4910128B2FD81B0106CC62902B*
- ] 4BD3DE93021F2E58E0DADC2A6B719275*
- ^ start of packet 0
- ]
- ] 42CC500AF360B70442E1E34FD4A06A07*
- ] 0B831E9A4AF23823208079789D83B4AC*
- ]
- ] 9F93047627184810F0872109C1A08404*
- ] 5E155F9AB334010245A9204603822788*
- ^ start of packet 1
- ]
- ] 8203A4C625679CF9359F15D951CDA7D8*
- ] 1706B02CB30C6F39E7E59DF270A41EAA*
- ] 108A20108A20
- ] 093A7709AA09
- ] 589A5318E13E000920CD10BB99014314*
- ] DA2E314999B78A8F2018024D29E10F28*
- ^ send rr7
- ^ send rr0
- ^ start of packet 2
- ]
- ] 159B8C283B4F6E01E8391B13D4370196*
- ] 993F4C4B30607703360D5D3294F4A814*
- ]
- ] Block 19 Print Page 45
- ]
- ] 513D3C2F39EBCACF93BEC6074810309A*
- ] A881D5794F830CF69076C420290258A5*
- ^ start of packet 3
- ]
- ] 4096E38C6360C0CA73F8EFA438ECA124*
- ] 84D9A48F43E6ECD294139C1048280225*
- ]
- ] 6E294CF030F288812AC071E20401024D*
- ] 471115A8FC20596C70E84D2750825A64*
- ] 108A20108A20
- ] 099A1B098A29
- ] 10ACACFC82B19417134CE4280E09A968*
- ] 020828309009D4803900D3E27AF1C5B3*
- ^ start of packet 4
- ^ send rr1
- ^ send rr2
- ] 108A20
- ] 097A37
- ] 8C06D92E780CA5B83562852626658FD2*
- ] 60541160B01C8ED5C0D097192185871E*
- ^ send rr3
- ]
- ] 517C2C10D6A1C2614A1DC4707C0E9777*
- ] 8302610228A2655AF28FA9C187DC3D8E*
- ^ start of packet 5
- ]
- ] Block 19 Print Page 46
- ]
- ] B8845BE938B1A0D5C0A40905D191386E*
- ] 26F00C444AF54AABA9C44DC12CB46167*
- ]
- ] 8490394B57681010BA3E730A340C2F74*
- ] 7195C98F0B0D025E2B60D81194BAADE6*
- ^ start of packet 6
- ] 108A2010
- ] 096A4109
- ] C2D441828D598A4E42FFBAEBA *
- ] 2DE4398C7F341FD202AD28FB2 *
- ^ send rr4
- ^ send rr5
- ] 8A20
- ] 5A53
- ] 5DF102CF94862CAF45554B18E10AD*
- ] 04811AADAF741249810753F64028F*
- ^ start of packet 7
- ]
- ] BC7AAF445E47A048CE7C9ED150029284*
- ] AFE0E9CCEABF920776660E6ED88860C5*
- ]
- ] 4126AC8AB0D19311A1182926FBF96450*
- ] 12F38C29C9943E5205B2FA79391DD266*
- ]
- ] Block 20 Print Page 47
- ] 108A20 108A20
- ] 094A61 093A77
- ] 8D10E98FC273DDCB70B5BE640948BF30*
- ] 8D020A2A2A64ECE6236BDA152D6549B6*
- ^ start of packet 0
- ^ send rr6
- ^ send rr7
- ]
- ] DEE5F25B12C7C49252A0647B4FEBA59D*
- ] BDC3797557736AF22FA01AC36A539C01*
- ]
- ] 264745EA101089017F1312493E8A20AB*
- ] 3DB8AA490282A2B8044E6BE67D804194*
- ^ start of packet 1
- ] 108A20
- ] 09AA09
- ] C0DF00DECEA203638B31ADE2CA1708BC*
- ] 494715E9698404C74AB4A7236CEDE1A9*
- ^ send rr0
- ]
- ] A546A6433186DF10AE9DDF6986DA08CF*
- ] 05959C8C93C3AE02D8256E9D0BC008AF*
- ^ start of packet 2
- ] 108A20
- ] 099A1B
- ] C4F8276AC8DF545302DA669963359994*
- ] 80C9A9000984DCA1353B897F2F87FAE7*
- ^ send rr1
- ]
- ] Block 20 Print Page 48
- ]
- ] 29A342E513A5400D060510809192E78F*
- ] EB0D2424209AB492B7280278A7CA9B05*
- ^ start of packet 3
- ]
- ] 7AAA3145CD25889F93A16D6031E0908E*
- ] 43C375E163AFA83C252BB75A9B31D40A*
- ]
- ] 33C957E00FD35B0E12A92D25A3100DA7*
- ] F43385F3545B004BA0C8A255F2028C24*
- ^ start of packet 4
- ]
- ] 4A8454CA518030E4452239D4894C8DC0*
- ] 925BD354869556E96A28041AC0654E11*
- ]
- ] 9C3490B2B69187A720EA162A6416A880*
- ] 8210094464340912C960C4229FD1A00E*
- ] 108A20108A20 10
- ] 098A29097A37 09
- ] 1017ACD0300603CCB5FA1903E401770C*
- ] 02AEAC32ECD8180353E178585BC1CDED*
- ^ start of packet 5
- ^ send rr2
- ^ send rr3
- ^ send rr4
- Here's another window violation.
-
- ]
- ] Block 20 Print Page 49
- ] 8A20
- ] 6A41
- ] D218956DA7EDC451E160BC704E1C4C3A*
- ] AA384C1198C239D17653BA8EE410A72C*
- ]
- ] 0CF7D010EBBE87258A099293110C953D*
- ] C01FEE0281293858F1051439025D4C7C*
- ^ start of packet 6
- ]
- ] 30928522196B0AF8A03F431A7AA8A5A0*
- ] E21447329F6810274279A117F5E5520D*
- ]
- ] E80A94625E5410CEB915F1B9AB2AC2C0*
- ] 003EC38CAE34029BAA6111EC98C92504*
- ^ start of packet 7
- ] 108A20108A20
- ] 095A53094A61
- ] 9B1505202E728342764012EC74075854*
- ] F08C048AD055BB732BA9241220DBBA9A*
- ^ send rr5
- ^ send rr6
- ]
- ] E0A80CC775192B120610A88AD017E94E*
- ] 0F82D81A1B29A301070264224B2B76F0*
- ^ start of packet 0
- ]
- ] Block 21 Print Page 50
- ]
- ] C74C0102504014218F4816C001BB2FEE*
- ] 94505412052098B47084FB6A2001F3C8*
- ] 108A20
- ] 093A77
- ] 51A3152920E6F8E7E8C670D910DB8E0A*
- ] 8EBE2183E66155C2805401600294A5DC*
- ^ send rr7
- ^ start of packet 1
- ]
- ] 24A224B905C5B0829C2329FCFC0939E8*
- ] 897E42B0837A0BE0D0C8C416191A0580*
- ]
- ] 050620A2D108C1A3FAD006B6907C0310*
- ] 28250FC571478A00D271C071E3301402*
- ^ start of packet 2
- ] 108A20108A20
- ] 09AA09099A1B
- ] 219A201DE967E8A01AC1A12E3870BDC6*
- ] FB2407C97343CED24354C73DA6C847E4*
- ^ send rr0
- ^ send rr1
- ]
- ] A85E379861263D0EC30C9A130B001C06*
- ] 0C52AED61EE0940100E2F90F334DE06E*
- ]
- ] Block 21 Print Page 51
- ] 108A20
- ] 098A29
- ] 0150 000000000000102F8594E1B9*
- ] 0D83 000000000000027DA2C81C1D*
- ^ send rr2
- ^ start of packet 1
-
- Hey, wait! We've already gotten packet 1 and ack'ed it.
- And its worse, this packet 1 is different that the last one!
- Which one is correct? The nulls are pretty interesting too.
- ]
- ] 9BEA53E93492A21033B415CE402C2451*
- ] 00DE96118EEACA6FC4405622A27068ED*
- ]
- ] FC045640E2A07524EE5968E71A0010DE*
- ] 41C5A163C7C46912F85B6CDC9B000217*
- ^ start of packet 2
-
- Another packet 2, and different from the last one.
- ]
- ] 9AE73E5F5EA94DD6101267A43E91A79C*
- ] 26B69FDB246D9E8B467D910FEDB30248*
- ]
- ] 985F9049B0572D2B64F589E4213D2959*
- ] 04C84B24626F169DC726E92C4543527C*
- ]
- ] 0900100099AD401EDB2A1623257884BE*
- ] 83000240AC76C09FDC37FEE8045929E3*
- ^ start of packet 3
- ]
- ] Block 21 Print Page 52
- ]
- ] 4598CD2407F2EA89DD779CA10009A1A5*
- ] 6A9BF588CB0524F1ECBAD9D8B54CC356*
- ] 108A20
- ] 097A37
- ] B06A7448DB000000000000 106789*
- ] D27698B2E8000000000000 025AA7*
- ^ send rr3
- ^ start packet 1
- More of those nulls. Yet another packet 1, and its
- different that the two previous ones.
- ]
- ] AF0028BF1D8CB02537961FA008005C58*
- ] 1E14C4B36E8A1B78D8302F06C0E16ADA*
- ]
- ] 06634882A6B35C755C8812A2120E0754*
- ] B709525C12288B2A454D1EB506E1220A*
- ]
- ] 0010FE98B1DFC694C45C5A5FBAD81116*
- ] 000250250F83E9CA47C040C485410096*
- ^ start of packet 2
- Another packet 2, and it's different that the last ones.
- ]
- ] 89D78A253958343FC1820EE44E48615A*
- ] 0533570B98B543FE7B2B8442C25E57C2*
- ]
- ] Block 22 Print Page 53
- ]
- ] 2616B2BC0010B99B51338CB9321A0715*
- ] C07D18850002A7A5F94F1B271B1A0516*
- ^ start of packet 3
- Another packet 3, and its different that the last one.
- ]
- ] 42640596F48DB463C0D20640A0405C87*
- ] 6ED9AD77F561773A00783C0D0100E04A*
- ]
- ] 52C0353C6D4B801A00 *
- ] CA60EE1FE16BD1F600 *
- ]
- ] Block 25 Print Page 54
- ] 109A12109A12109A12
- ] 097A37097A37097A37
- ] *
- ^ send rj3
- ^ send rj3
- ^ send rj3
- Since its been a long time and we haven't gotten packet 4,
- send some naks to try to try to get the modem to send it.
- ]
- ] *
- ]
- ] *
- ]
- ] *
- ]
- ] *
- ]
- ] *
- ]
- ] Block 34 Print Page 55
- ] 109A12109A12109A12
- ] 097A37097A37097A37
- ^ send rj3
- ^ send rj3
- ^ send rj3
- Still no packet 4, send some more naks.
- ] *
- ]
- ] *
- ]
- ] *
- ]
- ] *
- ]
- ] *
- ]
- ] *
- ]
- ] Block 43 Print Page 56
- ] 10AA0010AA001444444014444440
- ] 092A89092A890FFFFFF00FFFFFF0
- ] 00442*
- ] DAEF0*
- give up, send a close, get a "NO CARRIER".
- --
- Don "Truck" Lewis Phone: +1 916 478-8284 Silicon Systems
- Internet: gdonl@ssi1.com FAX: +1 916 478-8290 138 New Mohawk Road
- UUCP: {uunet,tektronix!gvgpsa.gvg.tek.com}!ssigv!gdonl Nevada City, CA 95959
-
-
- --
- Don "Truck" Lewis Phone: +1 916 478-8284 Silicon Systems
- Internet: gdonl@ssi1.com FAX: +1 916 478-8290 138 New Mohawk Road
- UUCP: {uunet,tektronix!gvgpsa.gvg.tek.com}!ssigv!gdonl Nevada City, CA 95959
-