User's Manual

T-311 11Mb High Gain Smart Ethernet Client User’s Guide
Gemtek Systems Page 34
user should be billed. PPPoE provides for each
user-remote site session to learn each other's
network addresses (during an initial exchange
called "discovery"). Once a session is
established between an individual user and the
remote site (for example, an Internet service
provider), the session can be monitored for
billing purposes.
PPTP: Point-to-Point Tunneling Protocol
(PPTP) is a protocol (set of communication
rules) that allows corporations to extend their
own corporate network through private
"tunnels" over the public Internet. Effectively, a
corporation uses a wide-area network as a
single large local area network. This kind of
interconnection is known as a virtual private
network (VPN).
R
RADIUS: RADIUS (Remote Authentication
Dial-In User Service) is a client/server protocol
and software that enables remote access
servers to communicate with a central server to
authenticate dial-in users and authorize their
access to the requested system or service.
RADIUS allows a company to maintain user
profiles in a central database that all remote
servers can share. It provides better security,
allowing a company to set up a policy that can
be applied at a single administered network
point. Having a central service also means that
it's easier to track usage for billing and for
keeping network statistics.
S
SNMP: Simple Network Management Protocol
(SNMP) is the protocol governing network
management and the monitoring of network
devices and their functions. It is not necessarily
limited to TCP/IP networks.
SNMP is described formally in the Internet
Engineering Task Force (IETF) Request for
Comment (RFC) 1157 and in a number of other
related RFCs.
SSL: The Secure Sockets Layer (SSL) is a
commonly-used protocol for managing the
security of a message transmission on the
Internet. SSL has recently been succeeded by
Transport Layer Security (TLS), which is based
on SSL. SSL uses a program layer located
between the Internet's Hypertext Transfer
Protocol (HTTP) and Transport Control
Protocol (TCP) layers. The "sockets" part of
the term refers to the sockets method of
passing data back and forth between a client
and a server program in a network or between
program layers in the same computer. SSL
uses the public-and-private key encryption
system from RSA, which also includes the use
of a digital certificate.
T
TCP: TCP (Transmission Control Protocol) is a
set of rules (protocol) used along with the
Internet Protocol (IP) to send data in the form
of message units between computers over the
Internet. While IP takes care of handling the
actual delivery of the data, TCP takes care of
keeping track of the individual units of data
(called packets) that a message is divided into
for efficient routing through the Internet.
TCP is a connection-oriented protocol, which
means that a connection is established and
maintained until such time as the message or
messages to be exchanged by the application
programs at each end have been exchanged.
TCP is responsible for ensuring that a
message is divided into the packets that IP
manages and for reassembling the packets
back into the complete message at the other
end. In the Open Systems Interconnection
(OSI) communication model, TCP is in layer 4,
the Transport Layer.
TCP/IP: TCP/IP (Transmission Control
Protocol/Internet Protocol) is the basic
communication language or protocol of the
Internet. It can also be used as a
communications protocol in a private network
(either an intranet or an extranet). When you
are set up with direct access to the Internet,
your computer is provided with a copy of the
TCP/IP program just as every other computer
that you may send messages to or get
information from also has a copy of TCP/IP.
TCP/IP is a two-layer program. The higher
layer, Transmission Control Protocol, manages
the assembling of a message or file into
smaller packets that are transmitted over the
Internet and received by a TCP layer that
reassembles the packets into the original
message. The lower layer, Internet Protocol,
handles the address part of each packet so
that it gets to the right destination.
Telnet: Telnet is the way to access someone
else's computer, assuming they have given
permission. (Such a computer is frequently
called a host computer.) More technically,
Telnet is a user command and an underlying
TCP/IP protocol for accessing remote
computers. On the Web, HTTP and FTP