normb@tekred.UUCP (Norm Babcock ) (11/01/84)
Douglas Robinson made a good comment about the inability of digital PBXs (CBXs) to handle direct connect modems. One that I'm familar with is the Danray system, (now Northern Telecom), which uses a six-wire telset. Two for transmit, two for receive, and two for telset power. The assumption is that a acoustic modem will work, but in general doesn't, for the primary reason that the modem tones "mean" something to the PBX, and the PBX goes off into never-never land, thinking it's supposed to hold, transfer, or something else. Some PBX/CBX have a feature called 'OPX', which allows the attachment of a standard 500 telset. They have to provide this feature to allow the customer the use of recorders and answer machines. Some people will refer to an OPX circuit used for data as a 'featured OPX'. This is in error. Whatcha need is a non-featured OPX, in which case, the PBX will ignore the modem tones. Another pitfall: incoming call signaling makes the modem go belly-up. Also most modems will not answer the double ring on incoming calls. (Inside calls are single, outside double). My favorite modem, after evaluating a large number of them, is the Racal-Vadic Auto Dial VA212PA. A little more expensive, but worth it. Norm
skip@gatech.UUCP (Skip Addison) (11/27/84)
All PBXs that I'm aware of (and I've looked at many) provide a means for
a standard touch-tone telephone to be connected directly on a "normal"
analog line. Most direct-connect auto-dial modems can use touchtone, so
there should be no problem. Right? :-)
--
from the DMZ of Skip Addison
The Office of Telecommunications and Networking
Georgia Tech, Atlanta GA 30332
CSNet: Skip @ GATech ARPA: Skip.GATech @ CSNet-Relay.ARPA
uucp: ...!{akgua,allegra,amd,hplabs,ihnp4,seismo,ut-ngp}!gatech!skipjc@sdcsvax.UUCP (John Cornelius) (12/01/84)
UCSD Hospital has a combination of pre deluge telephone systems that in some cases won't even accept a 2 wire RJ-11C jack. The PBX itself will not respond to touch tones in some areas of the hospital campus. Happily, such PBX systems are few and far between.