Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!usc!henry.jpl.nasa.gov!elroy.jpl.nasa.gov!gryphon!vector!telecom-gateway From: bill@toto.UUCP (Bill Cerny) Newsgroups: comp.dcom.telecom Subject: Re: PABX Communications With Local Telco Message-ID: Date: 9 Nov 89 15:46:28 GMT Sender: news@vector.Dallas.TX.US Lines: 36 Approved: telecom-request@vector.dallas.tx.us X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.dallas.tx.us X-TELECOM-Digest: volume 9, issue 504, message 4 of 5 In article , nvuxr!deej@bellcore. bellcore.com (David Lewis) writes: > Another approach often used, instead of running 7000 wire pairs, is to > locate a Remote Switching Unit, or RSU, on the customer premises. An > RSU is a "module" of a central office switch which has a control link > and a transport link to the main switch. The control link is > essentially an extension of the switch control bus, usually running > over fiber these days; the transport link is a high-capacity fiber > link. AT&T calls their version of this product the Optical Remote Module (ORM), and SW Bell uses ORM's to link Tenneco's various Houston locations into a "city-wide" centrex provided from a 5ESS. > The RSU isn't a switch in that it has no standalone > "intelligence", instead being directly controlled by the central > processor in the main switch Not strictly true anymore. I believe an AT&T Remote Switching Module (RSM) can be configured for stand-alone operations, and Northern Telecom will soon have a stand-alone remote switching unit. This touches on a very hot issue: telco provided CPE (a real no-no). When Tenneco selected SW Bell city-wide centrex, the PBX association filed a lawsuit which categorized the on-premise remote as CPE. SW Bell responded by categorizing it as central office plant. The judge ruled SW Bell may not locate the remote in the customer's portion of the building, i.e., SW Bell must lease space for its remote apparatus, or place the remote in a physically separate facility (e.g., underground vault). In the Tenneco situation, a corner of the basement was walled off, and a telco-keyed lock installed. As if that made a fundamental difference... Bill Cerny bill@toto | attmail: !denwa!bill | fax: 619-298-1656