Appendix

Ethernet address

The Ethernet address is the invariable, physical address of an Ethernet network component.

Firewall

Firewall describes network components which link an internal network (Intranet) to a public network (e.g. Internet), similarly to a router. Here the access to the, in each case, other network can be restricted or blocked completely depending on the access direction, the service used as well as the authentication and identification of network users. Another performance feature may be the encryption of data if e.g. the public network is only used as a transit means between two locally separated sections of an Intranet.

FTP – File Transfer Protocol

FTP is a TCP/IP-based protocol, which allows the transmission of complete files between two network users.

Gateway

Gateways connect – like also routers – different networks with each other. Whereas routers possibly convert the physical type of the network (e.g. Ethernet/ISDN) but leave the actual protocol (e.g. TCP/IP) untouched, Gateways allow to access networks with other protocols (e.g. TCP/IP on Profibus). Thus a Gateway also has the task to translate different communication protocols.

HTML – Hypertext Markup-Language

Markup language which defines via keywords how to display the contents in the browser, where to find multimedia elements and how to link which elements.

HTTP – Hypertext Transfer Protocol

The HTTP protocol is based on TCP and regulates the request for web contents and their transmission between HTTP Server and Browser. Today HTTP is the mostly used protocol in the Internet.

Hub

A hub, which often is also called star coupler, allows the connection of several users in a star-type network. Data packages received at one port are output equally at all other ports. In addition to hubs for 10BaseT (10Mbits/s) and 100BaseT (100 Mbits/s), there are so-called auto sensing hubs which detect automatically if the terminal equipment connected works with 10 or 100 Mbits/s.

ICMP – Internet Control Message Protocol

The ICMP protocol serves for the transmission of status information and error messages between IP network nodes.

Internet

The Internet currently is the largest integrated network worldwide which provides the network users connected with an almost unlimited communication infrastructure.

By using TCP/IP, the network users can call on services offered in the Internet such as e-mail, FTP, HTTP, etc., independent of the platform.

Intranet

A closed network (e.g. within a company) in the limits of which the network users call on internet- typical services such as e-mail, FTP, HTTP, etc. Normally, there is an interface from the Intranet to the Internet via routers or firewalls.

IP – Internet Protocol

Protocol enabling the connection of users which are located in different networks.