Simple Network Paging Protocol (SNPP) is a protocol that defines a method by which a pager can receive a message over the Internet.
It is a fairly simple protocol that may run over TCP port 444 and sends out a page using only a handful of well-documented commands.
It is relatively easy to connect to a SNPP server, only requiring a telnet client and the address of the SNPP server.
The port 444 is standard for SNPP servers, and it is free to use from the sender's point of view.
The protocol also allows multiple PAGE commands for one message, stacked one after the other, allowing a same message to be sent to several devices on the network with one MESS and SEND command pair.