Metasys N2:
Metasys N2 was developed by Johnson Controls as a network to interface their various devices and controllers. It is on the physical layer RS-485 set of data communications standards and supports 9600 baud, 8 data bits, and no parity and in half-duplex mode only. This network supports communications with a huge range of devices manufactured by Johnson Controls and some other companies. Metasys N2 by Johnson Controls is a master/slave protocol with one master only so it is not possible to have two devices performing this function on the same network.
SNMP:
Simple Network Management Protocol (SNMP) was originally made for the management of devices such as switches and routers, its usage has grown so much nowadays that it is used for monitoring of nearly any electronic device one can think of. It is a protocol which is majorly designed to manage networked devices from a single-central location. SNMP is now used to monitor and manage television broadcast studios, airborne military platforms, automated fare collection systems, emergency radio networks, energy distribution systems, and much more. Microsoft Windows Server 2003 provides SNMP agent software that works with third-party SNMP management software to monitor the status of managed devices and applications.