Elpro Technologies 450U-E Wireless Ethernet Modem & Device Server User Manual
Rev Version 1.0.12-Beta7
www.cooperbussmann.com/wirelessresources
79
facility so that access points can be optimally placed.
SSL
Secure Sockets Layer. A commonly used encryption scheme used by many online retail and
banking sites to protect the financial integrity of transactions. When an SSL session begins,
the server sends its public key to the browser. The browser then sends a randomly
generated secret key back to the server in order to have a secret key exchange for that
session
Sub network
or Subnet
Found in larger networks, these smaller networks are used to simplify addressing between
numerous computers. Subnets connect together through a router.
Switch
A type of hub that efficiently controls the way multiple devices use the same network so that
each can operate at optimal performance. A switch acts as a networks traffic cop: rather
than transmitting all the packets it receives to all ports as a hub does, a switch transmits
packets to only the receiving port.
TCP
Transmission Control Protocol. A protocol used along with the Internet Protocol (IP) to send
data in the form of individual units (called packets) 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 packets that a message is divided into for efficient routing through the Internet.
For example, when a web page is downloaded from a web server, the TCP program layer in
that server divides the file into packets, numbers the packets, and then forwards them
individually to the IP program layer. Although each packet has the same destination IP
address, it may get routed differently through the network. At the other end, TCP
reassembles the individual packets and waits until they have all arrived to forward them as
single message.
TCP/IP
The underlying technology behind the Internet and communications between computers in a
network. The first part, TCP, is the transport part, which matches the size of the messages
on either end and guarantees that the correct message has been received. The IP part is the
user's computer address on a network. Every computer in a TCP/IP network has its own IP
address that is either dynamically assigned at startup or permanently assigned. All TCP/IP
messages contain the address of the destination network as well as the address of the
destination station. This enables TCP/IP messages to be transmitted to multiple networks
(subnets) within an organization or worldwide.
VoIP
Voice Over Internet Protocol. Voice transmission using Internet Protocol to create digital
packets distributed over the Internet. VoIP can be less expensive than voice transmission
using standard analog packets over POTS (Plain Old Telephone Service).
VPN
Virtual Private Network. A type of technology designed to increase the security of information
transferred over the Internet. VPN can work with either wired or wireless networks, as well as
with dial-up connections over POTS. VPN creates a private encrypted tunnel from the end
user's computer, through the local wireless network, through the Internet, all the way to the
corporate servers and database.
WAN
Wide Area Network. A communication system of connecting PCs and other computing
devices across a large local, regional, national or international geographic area. Also used to
distinguish between phone-based data networks and Wi-Fi. Phone networks are considered
WANs and Wi-Fi networks are considered Wireless Local Area Networks (WLANs).
WEP
Wired Equivalent Privacy. Basic wireless security provided by Wi-Fi. In some instances, WEP
may be all a home or small-business user needs to protect wireless data. WEP is available in
40-bit (also called 64-bit), or in 108-bit (also called 128-bit) encryption modes. As 108-bit
encryption provides a longer algorithm that takes longer to decode, it can provide better
security than basic 40-bit (64-bit) encryption.
Wi-Fi
Wireless Fidelity: An interoperability certification for wireless local area network (LAN)
products based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11
standard.