IP Phone User's Manual

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

Æ VLAN 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.