Interlogix NS3502-8P-2S User Manual - Manual (Page 554)

IFS NS3502-8P-2S User Manual
554
HTTP
HTTP is an acronym for Hypertext Transfer Protocol. It is a protocol that used to transfer or
convey information on the World Wide Web (WWW).
HTTP defines how messages are formatted and transmitted, and what actions Web servers and
browsers should take in response to various commands. For example, when you enter a URL in
your browser, this actually sends an HTTP command to the Web server directing it to fetch and
transmit the requested Web page. The other main standard that controls how the World Wide
Web works is HTML, which covers how Web pages are formatted and displayed.
Any Web server machine contains, in addition to the Web page files it can serve, an HTTP
daemon, a program that is designed to wait for HTTP requests and handle them when they
arrive. The Web browser is an HTTP client, sending requests to server machines. An HTTP client
initiates a request by establishing a Transmission Control Protocol (TCP) connection to a
particular port on a remote host (port 80 by default). An HTTP server listening on that port waits
for the client to send a request message.
HTTPS
HTTPS is an acronym for Hypertext Transfer Protocol over Secure Socket Layer. It is used to
indicate a secure HTTP connection.
HTTPS provide authentication and encrypted communication and is widely used on the World
Wide Web for security-sensitive communication such as payment transactions and corporate
logons.
HTTPS is really just the use of Netscape's Secure Socket Layer (SSL) as a sublayer under its
regular HTTP application layering. (HTTPS uses port 443 instead of HTTP port 80 in its
interactions with the lower layer, TCP/IP.) SSL uses a 40-bit key size for the RC4 stream
encryption algorithm, which is considered an adequate degree of encryption for commercial
exchange.
I
ICMP
ICMP is an acronym for Internet Control Message Protocol. It is a protocol that generated the
error response, diagnostic or routing purposes. ICMP messages generally contain information
about routing difficulties or simple exchanges such as time-stamp or echo transactions. For
example, the PING command uses ICMP to test an Internet connection.
IEEE 802.1X