Understanding Networks
Network
Terminology
Gateway (gat'
wa): A gateway is a combination of hardware and software that allows
incompatible networks to exchange information. Gateways are necessary
because they allow computers using different protocols (i.e. PPP, PPTP,
SLIP) to communicate. The gateway can actually convert the protocol
(between different types of networks or applications) rather than just
support one protocol from within another. Many commercial services have
email gateways for sending messages between Internet
addresses.
A gateway can also be a computer that acts as a go-between for two or more networks that use the same protocol. In this case, the gateway functions as an entry/exit point to the network. The protocol may not need to be converted but other forms of processing may occur.
Gateway is also an earlier name for a router.
Relevance:
IRD NETWORK (i r d net' wurk): An IRD Network is short for Infra Red Network. Such a device allows for wireless digital data transmission between two points as far apart as two kilometers. Transmissions speeds range from 25 Mb/s to 622 Mb/s which are fast enough for most common network traffic. High speed, bi-directional bandwidth and auto-tracking allow for uninterrupted Ethernet, FDDI or ATM transmission where no optical cable exists. In theory, such a system can work at the same speed as optical fiber cables while avoiding the cost of laying those cables. This system is particularly appealing to managers operating LANs over a number of buildings, such as a hospital or university complex. Transmissions are interference free, reliable and secure. Installation is relatively simple, requiring that two units be placed with an unobstructed view of each other. Installation costs typically run a great deal less than that of traditional cable networks and running costs approximate those of minor electricity and maintenance fees. Adverse weather conditions should not interfere with transmissions either. The network link is maintained by movement in the optical axis that detects and compensates for horizontal and vertical deviation. IRD Networks can even transmit over greater distances by utilizing a 3R function that enables relay transmissions without any loss of signal quality.
Relevance: If these systems are as inexpensive and trouble free as claimed to be, they might make an intelligent alternative to networking school buildings that either are too old to wire optically or when considering networks for new consturction. For those buildings already wired, it does not make sense to convert to IRD Networks.
PPP:PPP is short for Point to Point Protocol and is a data link protocol that provides dial-up access over serial lines. This allows a computer running TCP/IP to connect to the Internet over standard phone lines using a high speed modem. It can run on any full duplex lines. Since being developed in 1991, it has become popular for Internet access as well as a method for carrying higher level protocols. PPP provides a more stable connection between a computer and the Internet than a SLIP connection and also offers error checking features unavailable with SLIP connections.
For more information about PPPs, visit the Department of Computer Science, University of Bonn site .
Relevance:
PPTP:PPTP
is short for Point to Point Tunneling Protocol, a new technology for
creating Virtual Private Networks (see below). This method for linking
data between devices encapsulates other protocols for transmission over
the Internet. Because its encryption capabilities, PPTPs are used to
create private networks within the public Internet. Remote users can
access their corporate networks via any Internet
Service Provider that
supports PPTP on its servers. This format was developed jointly by
Microsoft Corporation, U. S. Robotics and several remote access vendor
companies known collectively as the PPTP Forum. PPTP is used to ensure
that messages transmitted from one Virtual Private Network to another are
secure. Communication remains private as opposed to the vulnerable nature
of transmissions via the Internet.
Although PPTP has been submitted to the IETF (Internet Engineering Task Force) for standardization, it is currently only available on networks served by Window NT 4.0 and Linux. To download information on the technical specifications of PPTP, see this site by 3 Com Corporation .
Relevance:
SLIP (slip):SLIP
is short for Serial Line Internet Protocol and is a data link
format for transmitting data between two devices. The most common uses of
SLIP connections are to access the Internet and to provide a dial-up
access between two LANS (Local Access Networks). Point-to-Point Protocol
(PPP) is currently the more common method of connecting to the Internet.
SLIP is an older and simpler protocol but is very similar in both form and
function to PPP. The SLIP transmits IP packets, bits of data, over any
serial link-- whether a dial-up or a private line. This communication
protocol allows a computer connected to a server via a serial line (such
as a modem) to become an actual node on the Internet. This lets you run
network applications on your computer directly. With either a SLIP or a
PPP feed and the right software on your computer, you can run graphical
web browsing software, FTP files directly to your computer,
etc. Relevance:
Subnet Mask (sub' net
mask): A subnet mask is the method for splitting Internet
protocol (IP) networks into a series of subgroups, or subnets. A mask is
used to determine what subnet an IP address belongs to. An IP address has
two components, the network address
and the host address. Subnetting
allows the network administrator to divide the host part of the address
into two or more subnets. The mask is a binary pattern that is matched up
with the IP address to turn part of the host ID address field into a field
for subnets. The subnet mask is the network address plus the bits reserved
for identifying the subnetwork. It is called a mask because it can be used
to identify the subnet to which an IP address belongs.
Relevance: A saavy
network administrator can economically set up subnetwork masks so that IP
addresses can be shared.
VPN Network (v p n net' wurk) : VPN Network is short for Virtual Private Network and is a private network that is constructed using public wires to connect nodes (processing locations). The Internet is used as the medium for transporting data but security mechanisms ensure that only authorized users can access the network. Access is controlled; data is encrypted, secure and cannot be intercepted. Thus, a private network is configured within a public network. This is quite economical as VPNs take advantage of the economics of scale and built-in management facilities of large public networks. These networks appear as private national or international networks to the customer, but physically share the backbone trunks with other customers.
For a comprehensive list of links to various sites, see those listed by Webopedia .
Relevance:
Wireless Network (wir' les net' wurk): A Wireless Network, also known as a LAWN (Local Area Wireless Network), is a type of local-area network that uses high frequency radio waves rather than wires to communicate between processing locations. Transmissions are typically in an unlicensed frequency and do not require devices to be in line with each other. Wireless access points, base stations, are connected to an Ethernet hub or server and transmit radio frequency over an area of several hundred to a thousand feet. These transmissions can penentrate walls and other non-metal barriers. Roaming users can be handed off from one access point to another like a cellular phone system. Laptops use wireless modems that plug into an existing Ethernet port or that are self contained on PC cards. Stand alone desktops and servers use plug-in cards. Availability of such products should become realistic for small office and home technologies in the immediate future. These systems have a more limited range and do not support roaming.
Wireless Design Online provides a
comprehensive resource on the subject of LAWNS.
Relevance: The
elimination of computer wires from an elementary school would be
incredibly liberating. Technology could come to the students rather
than vice versa. Young children often disrupt network communication
inadvertently by simply kicking loose connections. Many hours are
unnecessarily spent troubleshooting such mishaps. The less stuff there is
for a child to "damage," the longer equipment will last. In addition,
being able to transport equipment anywhere within the given transmission
range would allow great flexibility in the use of that equipment and
possibly encourage greater teacher use. As
always, expense will
determine how quickly such advanced technology will be employed at the
elementary school level.
The above information was researched from the following sites.
Connected: An Internet Encyclopedia
Glossary of PC and Internet Terminology
Tech Encyclopedia
Network
Lingo
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