SNPP or the Simple Network Paging Protocol was developed
as an effort to create an Internet communication protocol
that would allow for text messages to be passed through the
Internet to telecommunication and paging providers. SNPP was
initially developed as a one-way solution but it has recently
evolved into a protocol capable of supporting two way messaging.
SNPP is a TCP/IP protocol similar to FTP, HTTP, SMTP, etc.
The simplest functions provide reliable delivery of a pager
identification and an alphanumeric message to a paging system,
rather than using an assigned dialup phone line to enter DTMF
tones or negotiate a modem connection.
SNPP is a simple way for delivering wireless messages, both
one and two-way, to appropriate receiving devices. In its
simplest form, SNPP provides a simple way to implement communication
between the Internet and a TAP/IXO paging terminal. In its
latest form, SNPP provides a method for communicating and
receiving end-to-end acknowledgments and replies from two-way
messaging devices (such as ReFLEX units).
The SNPP protocol is a sequence of commands and replies,
and is based on the philosophy of many other Internet protocols
currently in use.
SNPP has several input commands (the first 4 characters of
each are significant) that solicit various server responses
falling into the following categories:
2xx - Successful, continue
3xx - Begin DATA input (see "DATA" command)
4xx - Failed with connection terminated
5xx - Failed, but continue session SNPP version 3 (two-way)
adds the following categories:
7xx - UNsuccessful two-way specific transaction, but continue
8xx - Successful two-way specific transaction, continue
9xx - Successful QUEUED two-way transaction, continue
The first character of every server response code is a digit
indicating the category of response. The text portion of the
response following the code may be altered to suit individual
applications. The session interaction, especially at SNPP
level one, is actually quite simple (hence the name). The
client initiates the connection with the listening server.
Upon opening the connection, the server issues a "220" level
message (indicating the willingness of the server to accept
SNPP commands). The client passes pager ID information, and
a message, then issues a "SEND" command. The server then feeds
the information to the paging terminal, gathers a response,
and reports the success or failure to the client.
software that adheres to the SNPP protocol follow
the above steps.
More on SNPP...