g) Inexpensive, so it can be widely deployed.

That's why I suggested talking to a college sophomore. This is the kind of thing that electronics engineering students do for a 3rd year project.

A Basic Stamp might be the platform for such;

I don't think that a Stamp or PICAXE will work. These are PIC devices with built-in BASIC interpreters. To do the SNMP, you need an IP stack on the device and that really has to be done in assembly language. All of the PIC projects I have seen interfacing to Ethernet or to RS-232 IP interfaces, have been done in assembly. As I said, 99% of the design work on this is available out there on the web. You just need someone willing to put it all together and manufacture the boxes. For an alternative approach, have a look at Netguardian. http://www.dpstele.com/products/ne/netguardian/ High capacity SNMP Alarm connector, NEBS 3, etc. --Michael Dillon