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Building Technologies
Appendix
2015-10-13
Network
A network (LAN, WAN) is a linked group of devices connected via various lines
or radio sharing common resources such as data or peripheral devices.
Network adapter
Hardware to connect network components to a local area network (LAN).
Connection can be wired or wireless.
Network Address
Translation
See NAT
Network configuration
All settings an IP-based device requires to work on a network: IP address, subnet
mask, standard gateway, preferred DNS server, and alternate DNS server.
PAT
PAT or NPAT (Network and Port Address Translation) translates all private network
addresses into one public (dynamic) IP address. In this process, port numbers are
exchanged in addition to addresses when there is a connection. As a result, an
entire private network only requires one single registered public IP address.
Plant room
The ISP provides the connection to the Internet via DSL or cable TV (at a fee).
Point-to-Point Protocol
See PPP
Port
Ports are used to exchange data between different applications on a network. The
port number addresses the application within a network device. The combination
of IP address and port number serves as a unique identification of the recipient or
the sender of the data package with the network.
Internet service applications work with set port numbers (HTTP 80, FTP 21).
See
http://www.iana.org/assignments/port-numbers
for registered port numbers.
Port numbers 0 to 49151 are set and reserved, port numbers 49152 to 65535 are
dynamic (and therefore available).
Port and Address
Translation
See PAT
Port Forwarding
With port forwarding, the router forwards data packages from the Internet, destined
for a particular port, to the port of the responsible network device. As a result,
servers (Web Server) integrated in a LAN, can be reached from the Internet
(without a need for a public IP address). Port Forwarding is achieved by the correct
NAT / PAT definition in the router.
PPP
Protocol for dial-up connection of a computer to the ISP.
PPP over Ethernet
See PPPoE
PPPoE
Protocol used to connect to the Internet via ADSL or DSL.
Private IP address
The private IP address (local IP address) is the address of a network device on a
local network (LAN). The provider assigns this address at will. DSL routers have a
public IP address for the WAN and a private IP address for the LAN. The following
IP ranges are recommended for private IP addresses:
10.0.0.0…10.255.255.255
à
Class A.
172.16.0.0…172.31.255.255
à
Class B.
192.168.0.0…192.168.255.255
à
Class C.
The first IP address xxx.xxx.xxx.0 and the last IP address xxx.xxx.xxx.255 in a
network segment cannot be used, as xxx.xxx.xxx.0 is reserved for the network and
xxx.xxx.xxx.255 for broadcasting.