53 lines
2.4 KiB
Plaintext
53 lines
2.4 KiB
Plaintext
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cat crashess
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Article 56 of comp.dcom.telecom:
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Path: csustan!lll-lcc!styx!ames!ucbcad!ucbvax!kitty.UUCP!larry
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From: larry@kitty.UUCP
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Newsgroups: comp.dcom.telecom
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Subject: Submission for mod.telecom ("Crashing" a Central Office)
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Message-ID: <8704261435.AA29050@seismo.CSS.GOV>
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Date: 26 Apr 87 14:35:33 GMT
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Sender: daemon@ucbvax.BERKELEY.EDU
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Distribution: world
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Organization: The ARPA Internet
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Lines: 35
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Approved: telecom@xx.lcs.mit.edu
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> Finally, If both my best friend and myself set call forwarding to
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> each other, what happens when someone calls?
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>
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> [ ... Also, if you forward to someone who forwards to
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> you the call goes "click", "click", busy. The two clicks are the
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> trunks going between your central offices. If you do this to someone
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> on the same ESS machine, it gives you a busy immediately. This is
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> useful especially if you have your calls forwarded from home to work
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> and vice versa. You can safely forward your calls bi-directionned until
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> you get home and clear the forwarding. Also, I crashed our central office
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> forwarding once to someone on the same machine (that was 12 years ago).
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> --jsol]
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Re: the comment about "crashing" the central office...
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If anyone finds this hard to believe, I know of a specific example
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where there was a bug in a particular generic software release used on some
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early #2 ESS machines which had just been installed by New York Telephone
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to replace SxS CDO's during the mid 70's.
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By using three telephone lines, and setting them up to forward as
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A --> B --> C --> A, a call from another telephone to A as a "seed" would
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force the #2 ESS to crash and switch to the standby processor, whereupon
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a second occurence would wipe out the standby processor until the call
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attempt was discontinued. This situation would also set off remote alarms
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at the SCC which handled these unattended #2 ESS machines.
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Needless to say, a software patch was quickly developed by WECO...
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The above scenario was probably unanticipated by the WECO team
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that designed and wrote the software. The public, however, seems to have
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a knack for discovering these flaws rather quickly.
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<> Larry Lippman @ Recognition Research Corp., Clarence, New York
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<> UUCP: {allegra|ames|boulder|decvax|rocksanne|watmath}!sunybcs!kitty!larry
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<> VOICE: 716/688-1231 {hplabs|ihnp4|mtune|seismo|utzoo}!/
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<> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?"
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well?
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