Abbreviations and Technical Terms
UDP
Stands for User Datagram Protocol and can be used instead of Æ TCP if reliability is not an issue. UDP does not guarantee that packets will be de- livered, nor does it ensure that packets will arrive in a certain order.
URI
Abbreviation of Uniform Resource Identifier. Content is identified in the In- ternet with a URI. In general, content refers to files of all possible format, for example text, HTML, XML, video, sound to name but a few. The most frequent form of URI is a URL. A typical URI describes:
•the mechanism for accessing the content (for example a protocol, such as http, ftp or file)
•the computer on which the content is located
•the specific name of the content on this computer (usually a file name)
The parts are optional which is why a file name is a (relative) URI.
URL
Abbreviation of Uniform Resource Locator. A URL is the address of a file that can be accessed over the Internet. The type of file is defined by the access protocol (not the file type). For example, the HTTP protocol sup- ports HTML pages, Java applets, CGI scripts, etc. A URL consists of
•the access protocol
•a computer name (the domain)
•a specific file name
VLAN
Abbreviation of "Virtual Local Area Network."
The division of an Æ IP network into autonomous administration groups (domains). One way of indicating association with a VLAN is to use a
ÆVLAN ID.
VLAN is therefore a network structure with all the properties of a conven- tional LAN, but without a physical connection. The distance between sta- tions in a LAN is limited; a VLAN, on the other hand, lets you connect even more remote nodes to a virtual local network.
VLAN ID
With switches, VLAN divisions can exceed switch boundaries. A special mechanism is provided for this. It allows you to send packets between the switches and identifies them as belonging to a specific VLAN. Every VLAN is assigned a specific VLAN ID (VID) for this.
79
