Wired Room Intercom Project

two station

• http://www.instructables.com/id/CAT5-Intercom/
• http://boingboing.net/2014/02/05/howto-make-an-intercom-out-of.html
• http://makezine.com/projects/simple-intercom-from-a-pair-of-old-corded-phones/

The idea of using standard telephones as room intercoms. Using POTS phones as intercoms.

• http://electronics.stackexchange.com/questions/58249/how-to-create-a-multi-extension-intercom-system-using-wired-phones

Use a PBX, the Asterisk software, and a PC. Talkswitch is a company.