From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 8870 invoked from network); 26 Sep 2023 01:51:09 -0000 Received: from minnie.tuhs.org (2600:3c01:e000:146::1) by inbox.vuxu.org with ESMTPUTF8; 26 Sep 2023 01:51:09 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id E0E2540424; Tue, 26 Sep 2023 11:51:04 +1000 (AEST) Received: from omta040.useast.a.cloudfilter.net (omta040.useast.a.cloudfilter.net [44.202.169.39]) by minnie.tuhs.org (Postfix) with ESMTPS id 5136C402EF for ; Tue, 26 Sep 2023 11:50:58 +1000 (AEST) Received: from eig-obgw-5003a.ext.cloudfilter.net ([10.0.29.159]) by cmsmtp with ESMTP id kvUhqKfsKyYOwkxE1qInaJ; Tue, 26 Sep 2023 01:50:57 +0000 Received: from shared056.arvixe.com ([129.121.4.205]) by cmsmtp with ESMTPS id kxE0qF3K4PK6RkxE0qThAo; Tue, 26 Sep 2023 01:50:56 +0000 X-Authority-Analysis: v=2.4 cv=JPsoDuGb c=1 sm=1 tr=0 ts=65123900 a=ZXEiJ4ldN1eQiIvORaK8zw==:117 a=ZXEiJ4ldN1eQiIvORaK8zw==:17 a=OWjo9vPv0XrRhIrVQ50Ab3nP57M=:19 a=dLZJa+xiwSxG16/P+YVxDGlgEgI=:19 a=IkcTkHD0fZMA:10 a=zNV7Rl7Rt7sA:10 a=MwmYBGSu7XQA:10 a=AoeSMSUmAAAA:8 a=7VQDIwoScIseAoKmGoYA:9 a=QEXdDO2ut3YA:10 a=2UY7SMgi64q-0UtCmZ5F:22 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=humeweb.com ; s=default; h=To:References:Message-Id:Content-Transfer-Encoding:Cc:Date: In-Reply-To:From:Subject:Mime-Version:Content-Type:Sender:Reply-To:Content-ID :Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To: Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe :List-Post:List-Owner:List-Archive; bh=uGCotYJMaJ9ClFz7IYKbcu+pdkLXTdOluRUtnMpW6M8=; b=WTFNzlXFdKPHUx2xA2ZAyrMt/L XDBgf6ZFoqOnLyx82v/50Btl0NP/kWQDuE6Ec5n0jGgkKC8vWFUFiWEQzZXhdMNSCdNTP14o4WekT 3OFfpcCO76SnN19sOojBqLAXiSNiGtbefg3e8GInw8neJ+BB3ztx0hrp/lc8T11ZpdAs=; Received: from 99-98-248-85.lightspeed.irvnca.sbcglobal.net ([99.98.248.85]:56542 helo=smtpclient.apple) by shared056.arvixe.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1qkxDz-003bIh-KE; Mon, 25 Sep 2023 20:50:55 -0500 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3731.600.7\)) From: Andrew Hume In-Reply-To: Date: Mon, 25 Sep 2023 18:50:52 -0700 Content-Transfer-Encoding: quoted-printable Message-Id: <92D94A5E-AE0F-446D-8C26-C8EF1E672230@humeweb.com> References: To: segaloco X-Mailer: Apple Mail (2.3731.600.7) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - shared056.arvixe.com X-AntiAbuse: Original Domain - tuhs.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - humeweb.com X-BWhitelist: no X-Source-IP: 99.98.248.85 X-Source-L: No X-Exim-ID: 1qkxDz-003bIh-KE X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 99-98-248-85.lightspeed.irvnca.sbcglobal.net (smtpclient.apple) [99.98.248.85]:56542 X-Source-Auth: andrew@humeweb.com X-Email-Count: 1 X-Org: HG=asoshared_arvixe;ORG=aso; X-Source-Cap: YWh1bWU7YWh1bWU7c2hhcmVkMDU2LmFydml4ZS5jb20= X-Local-Domain: yes X-CMAE-Envelope: MS4xfIZwi++7am/a5Ye95wOIsh2eBoBbFg7KU/J3tGwVtAH77xUl4Up2/Fg4krDvwi3arBFSaU7rEV9Th5EW9SWuN4NkO/JsYTJiCZCxWSpin5YHbxuy5gBx 79H57vffpqDuDNcbN2BDWnAu9EfYtMVe9QhtlwkXp4KN3RkBYJXR/UVNKOGDUHPowuUVy5LIiqdbhg== Message-ID-Hash: BRQOI6THFNF554AUSO73XHNYYDPWSVO6 X-Message-ID-Hash: BRQOI6THFNF554AUSO73XHNYYDPWSVO6 X-MailFrom: andrew@humeweb.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: The Eunuchs Hysterical Society X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: Known Specimens of Pre-5ESS UNIX Telephone Switching Software? List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: i=E2=80=99m sure there are standing references to all this. but as i = recall, the 5ESS was a more or less local switching system. the guts of the long distance network were embedded in the (roughly) 140 = 1ESS=E2=80=99s. they ran a completely separate (and substantially older) code that supported = things like SS7 (signaling code that was NOT embedded in the voice channel). the 1ESS was a complex = piece of equipment. my interaction with this was tangential. throughout the 1980-90s, i had = a tight grip on how accounting messages were handled within AT&T and wrote some C code that = handled a a transition from one level of the standard software to another level. = and that code ran inside the 1ESS. but this was a long time ago. > On Sep 25, 2023, at 6:24 PM, segaloco via TUHS wrote: >=20 > Hello, my studies lately bring me to the question: Are there any = extant examples of telephone switching software, built on UNIX, from the = various parts of the Bell System prior to the introduction of the 5ESS = and 3B20D? My focus veers earlier as some 5ESS/3B20D/DMERT technology = is still in active use, that sleeping dragon can lie. >=20 > What's gotten me curious is reading about 1ESS in a BSTJ volume I = picked up, noting the particulars on how previous concerns of manual and = electro-mechanical systems were abstracted into software. Even without = surviving examples, were previous systems such as the 1ESS central = control ever ported to or considered for porting to UNIX, or was the = hardware interface to the telco lines too specific to consider a future = swap-out with, say, a PDP11 running arbitrary software? Columbus's SCCS = (switching, not source code) also comes to mind, although all I know = that survives of that is the CB-UNIX 2.3 manual descriptions of bits and = pieces. >=20 > By the way, it's funny, I have UNIX to thank for my current = experiments with telephones and other signalling stuff, what with making = me study the Bell System more generally. It's starting to come full = circle in that I want to take a crack at reading dialing, at least = pulse, into some sort of software abstraction on a SBC that can, among = other things, provide a switching service on top of a UNIX-like kernel. = I don't know what I'd do with such a thing other than assign work = conference call rooms their own phone numbers to dial with a telephone = on a serial line...but if I can even get that far I'd call it a success. = One less dependency on the mobile... >=20 > - Matt G.