Swift Griggs' Indy ISDN faq.  6/26/98 
Updated 9/8/98 by Christopher Blencowe

Q. Do INDY's support ISDN "out of the box" ?
A. No, not in the United States. You must buy an external NT1 terminator
        from a 3rd party. I belive that SGI used to make them too. There
        is some referance to them in various places. However, I couldn't 
        find anyone selling them and I ended up buying an excellent NT-1
        from DTC for around 100 bucks. http://www.digitaltx.com

Q. Can I use analog voice devices with the INDY's ISDN setup?
A. Nope. You have to have a Terminal Adapter (TA)  that supports that 
        type of thing. I've used 3Com's Impact IQ ISDN TA's and they 
        seem to do about the best job for the least money. Make sure
        that if you need this feature that you get an ISDN TA that 
        supports "ringing" the device, or else all you'll be able to 
        do is make calls, and your device (a FAX for example) won't ever
        answer the calls

Q. What type of interface does the INDY have?
A. It's an S/T type of interface. What the phone company will put into the
        wall is called a U interface. That's why you need an NT-1

Q. What kind of cable do I need for the S/T interface? What about the U
        interface? 
A. For the U interface use a non-twisted cable with a RJ-11 (4 wire) on
        one end and a RJ-48C (8 wire) on the other. Yes, an RJ45 will work
        too (same thing different purpose). Use the middle wires on both 
        jacks. That's pins 2 and 3 on the RJ-11 and pins 4 and 5 on the
        RJ-48C. As for the S/T interface you need a stright through RJ-45
        untwisted, shielded cable. Usually you can use certified ethernet
        calbles that have all wires (not just 1, 2, 4, 5) wired stright 
        through. But you can't run it too far since it's twisted pair.

Q. I'm trying to install support for ISDN with IRIX 6.2 and the install
        says that I need some package that isn't on the distribution.
A. Just do the regular install from the first CDROM then after it boots
        use the "swmgr" software manager to install the ISDN programs from
        the second IRIX 6.2 CD. After that you can go back and use the
        software manager to install ISDN and PPP support with no problem
        from the first CD.

Q. It's asking me for a switch type, and SPID numbers how do I know what
        these are?
A. Call your telco and ask them, and be sure to complain that they didn't
        tell you in the first place. 

Q. I'm using a 5ESS and the area for my second SPID number disappears 
        when I try to setup my ISDN.
A. Your Indy will query the switch using the signaling channel to find
        out what the second SPID is automagically. There are a few other
        types of switches that will do this to. DMS100 is not one of them.

Q. I'm running IRIX 5.3 and I'm having trouble creating bonded connections
        to a Cisco or a Ascend router.
A. SGI has a patch for that. I haven't experianced this since I'm only
        running 6.2 but if you do a search on their site for INDY and
        ISDN you'll find it.

Q. Do Indys support multiple subscriber numbers on EuroISDN (called MSN)?
A. Apparently not.  Only one Indy on one ISDN bus may be used, unless there 
         is no need for incoming services.


Hope this helps
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