george@swbatl.UUCP (6544) (10/04/89)
In article <1989Oct2.180350.11954@pcrat.uucp> rick@pcrat.UUCP (Rick Richardson) writes: >If you don't find a board level solution for the Mac, you can always >go with an AT&T 7500 ISDN terminal adapter. True, but the TA (internal or external) must be compatible with your ISDN service. An AT&T 7500 TA is fine assuming you're on an AT&T switch. If you happen to be on Northern Telecom switch, for example, it's not going to work. There are some TAs out there that will work with different makes of switches, but you still need to know what switch is being used so that you can program the TA appropriately. George D. Nincehelser Advanced Technology Laboratory Southwestern Bell Telephone
rick@pcrat.uucp (Rick Richardson) (10/04/89)
In article <837@swbatl.UUCP> george@swbatl.UUCP (George Nincehelser) writes: > >True, but the TA (internal or external) must be compatible with your >ISDN service. An AT&T 7500 TA is fine assuming you're on an AT&T >switch. If you happen to be on Northern Telecom switch, for >example, it's not going to work. Aren't 'standards' fun. The way I experienced it, the CCITT failed to standardize enough supplementary services. (Or maybe you could call it a premature standardization of an incomplete specification). So we had two ISDN protocols here in the US - AT&T and NTI. Then, just when enough pressure had been applied to AT&T and NTI to support each others private code sets, Bellcore got into the act and created a third code set. But not a union of the two code sets. Rather more a common subset. Thus leaving us with not one code set, but three code sets. And did anybody think to add any real value to the Bellcore codeset, such as remote AP control/status of the telephone/TA? Or maybe switch downloading of the telephone firmware into NV storage. Or ... Nope, just another way to do the same old worn out voice feature set. On top of it all are the plethora of datacom possibilities. LAPD/X.25 on D, LAPD/X.25 on B, LAPB/X.25 on B, Mode 2 DMI on B, circuit/packet switched on B, (fill in blank) rate adaption on B. Would not LAPD/X.25 have sufficed for packet switched B or D? And one rate adaption scheme have sufficed for circuit switched B? I still hear the ISDN software developers complaints -- "haven't written a new line of code in a year". They forgot that this time last year, they were (I was) saying the same thing. At this time, I would applaud any switch manufacturer/terminal vendor with the fortitude to deliver real capabilities (in a private codeset) for services that would not be possible outside of ISDN. I'd give a standing ovation to Bellcore or the CCITT if they could envision these needs and standardize them before a vendor is forced to invent them. I also applaud RBOCs that deploy SS7 without waiting for the market to develop, or should I say "develop a market by deploying SS7". -- Rick Richardson | Looking for FAX software for UNIX/386 ?????? mention PC Research,Inc.| WE'RE SHIPPING your uunet!pcrat!rick| Ask about FaxiX - UNIX Facsimile System (tm) FAX # (201) 389-8963 | Or JetRoff - troff postprocessor for the HP {Laser,Desk}Jet