First, look inside the cabinet and see if there is a floppy disk that has utilities on it. If you find it, there will be a few files on there (pansi.kbd, pansi3.kbd, tvi910.kbd) that you will need to copy into the procomm directory - you will need to use these keyboard mappings so that you don't have problems with the terminal emulation.
For basic 9006 communication you can use 9600,N,8,1 for your communications parameters - terminal type is ANSI. Some switches will let you use 19,200 baud.
Also look inside the cabinet for a DAT tape labelled ISYAP or something like that - that will most likely be the current version of the system software, which would be like 9006.4 SMRJ or something like that.
There is no default login - the tech login changes depending on the dealer that sets up the switch, and is impossible to predict.
You can login through the RMX port. On the model 30 the RMX port is the top port on the DM3L or DM4L card. You can connect there and use 4800,E,7,1 as your comm parameters. You must use the TVI910 Terminal type, and you MUST have the tvi910.kbd keyboard file installed. You can do some things through that port without a password, but for higher functions it will still ask for one because you can do more damage through that port than you can going in the regular way.
If you have a DM3L card as your main processor board you probably have software release 9006.3 or lower. If you have a DM4L card you probably have software release 9006.4 or 9006.5. There is also a 9006.6 and I don't remember what the card is for that one, but it is different than the rest and runs unixware instead of the full version of unix.
That's the most I can give you - sorry.