Dialing from a PC using SQL*Net with TCP/IP

I am looking into hooking up a client/server environment in which an application (written in C++) resides on a PC and Macintosh, and the Oracle Database resides on a Pyramid Unix machine. After speaking with some people at Oracle, I found I needed SQL*Net and Pro*C (for the OCI libraries) for each of the Mac's or PC's I hook up. That is fine.

My question is what else I would need on the PC or Mac to be able to dial-in, without having the PC or Mac on a direct line to the network?

Do I need some kind of Protocol software for the PC's and Mac's in order to dial-in and use TCP/IP? Will SQL*Net support these?

One person told me I could use something like XVision for the PC (in order to run X-Windows on the PC) and as long as I had a Shiva(sp?) Net - Modem E (or something like that) on the Pyramid, the Mac could dial directly in. Any info you can give me will help.

Feel free to e-mail me directly.

                                        Thanks again,

                                                Don Taber