madden@sdcc3.UUCP (Jim Madden) (12/10/84)
My campus is about to embark on project that will replace lots of four wire data circuits supplied by the telephone company with connection boxes on a broadband cable. A part of the project involves installation of the local wire that will connect terminals and computers to network boxes one or two offices away. To minimize labor costs for this part of the project, we plan to use RJ11 6 wire modular plugs, wall sockets and RS232 connectors of the kind supplied by Nevada Western or Modtap. The questions for the network are: Have other institutions done similar things and can they provide us with insights into the pitfalls facing us? Is there any standard for the association (by color code or location on the RJ11 jack) of the individual leads in the cables and the pins of the RS232 connector? In the absence of standards, are there well know pieces of equipment from IBM, ATT, or other companies that we should regard as an effective standard? Although four wire circuits have been sufficient for most of our terminal connections in the past, in this project we plan to install six wire circuits for future flexibility. We've chosen 6 wires primarily since this seems to provide adequate signaling in both directions and because such circuits can use RJ11 connectors. More wires require significantly more expensive equipment. Are we making a mistake here? Does anyone have any late breaking information on broadband attachment equipment for terminal-to-host, host-to-host and micro-to-anything that will help us make a choice of such equipment in the next month? In a week or two, I'll summarize any useful information I receive. Jim Madden sdcsvax!madden
phil@amdcad.UUCP (Phil Ngai) (12/12/84)
> My campus is about to embark on project that will replace lots of four > wire data circuits supplied by the telephone company with connection > boxes on a broadband cable. A part of the project involves > installation of the local wire that will connect terminals and > computers to network boxes one or two offices away. To minimize labor > costs for this part of the project, we plan to use RJ11 6 wire modular > plugs, wall sockets and RS232 connectors of the kind supplied by Nevada > Western or Modtap. Is 6 wire enough? Let's see: TxD, RxD, GND, CTS, RTS, DTR, DCD. If you don't have modems it might be. Otherwise, perhaps not. We are using 8 wire. It ties in nicely with the use of 25 pair cable and 258A "harmonicas". -- I'm not a programmer, I'm a hardware type. Phil Ngai (408) 749-5790 UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!phil ARPA: amdcad!phil@decwrl.ARPA
ron@brl-tgr.ARPA (Ron Natalie <ron>) (12/17/84)
> My campus is about to embark on project that will replace lots of four > wire data circuits supplied by the telephone company with connection > boxes on a broadband cable. A part of the project involves > installation of the local wire that will connect terminals and > computers to network boxes one or two offices away. To minimize labor > costs for this part of the project, we plan to use RJ11 6 wire modular > plugs, wall sockets and RS232 connectors of the kind supplied by Nevada > Western or Modtap. RJ11's are just fine if you don't plan to plug and unplug them much. They aren't designed to handle that and do break easily. It offends my sense of order to use them on terminal lines almost as much as it would to use 110v plugs, I'm afraid that if two things can be plugged into each other, they will, and some terminal will blow up when it get's the ring voltage. -Ron