I need a modem emulator or similar to "system test" a server that includes modem communications with the outside world, because I can't actually dial the outside world for tests.
I work with a server that includes a bank of modems and phone lines that connect to hundreds of remote devices in the outside world. The remote devices are installed at our customer sites, and are relatively simple -- they auto answer, handshake with the server application, accept a command, upload some data, then disconnect. The problem is how do you fully system test such a server without hundreds of external test sites? (We can't contact our customers for the tests.)
My thought is emulation -- build system emulating modem bank and the remote devices. The test server's comm ports would be physically connected to the emulator's comm ports (i.e. null modem), and the emulator would look like modem hardware (proper treatment of hook, RTS/CTS, AT commands, etc.) so the test server would think it is dialing the outside world and connecting to remote devices, when in fact it is only talking to our emulator.
Problem: where can I get specs to code (or get actual code) for a modem emulator? (Our remote device protocol is simple and 100% known to us, so emulating that part is easy.)
Thank you in advance,