Pre-diallingSee Block dialling.Private IP AddressSee Public IP address.Protocol

Describes the agreements for communicating within a Network. It contains rules for opening, administering and closing a connection, about data for- mats, time frames and possible error handling.

Proxy/Proxy server

Computer program that controls the exchange of data between Client and Server in computer networks. If the phone sends a query to the VoIP server, the proxy acts as a server towards the phone and as a client towards the server. A proxy is addressed via

IP address/Domain namen and Port.Public IP address

The public IP address is the address for a network component on the Internet. It is assigned by the Internet Service Provider. Devices that act as a link from a local network to the Internet (gate- way, router) have a public and a local IP address.

See also: IP address, NAT

Q

Quality of Service (QoS)

Describes the Quality of Service in communication networks. Differentiations are made between various Quality of Service classes.

QoS influences the flow of data packets on the Internet e.g. by prioritising data packets, bandwidth reservation and packet optimisation.

In VoIP networks, QoS influences the voice quality. If the whole infrastructure (router, network server etc.) has QoS, the voice quality is better, i.e. fewer delays, less echoing, less crack- ling.

Glossary

R

RAM

Random Access Memory

Memory in which you have reading and storage rights. Items such as melodies and screen pictures are saved in the RAM after being loaded onto the phone via the Web configurator.

Registrar

The registrar manages the Network subscribers's current IP addresses. When you register with your VoIP pro- vider, your current IP address is saved on the registrar. This means you can also be reached when on the move.

Ringback when the call is not answered

=CCNR (Completion of Calls on No Reply). If a participant does not respond when called, a caller can arrange an automatic ringback. As soon as the destination phone has completed a call and is free again the caller is rung back. This feature must be supported by the exchange. The ring- back request is automatically cancelled after about 2 hours (depending on the VoIP provider).

Ringback when the number is busy

=CCBS (Completion of Calls to Busy Subscriber). If a caller hears the busy tone, he or she can activate the ring- back function. As soon as the connec- tion is free the caller is rung back. As soon as the caller lifts his receiver the connection is made automatically.

ROM

Read Only Memory

A type of memory that can only be read, as opposed to RAM which can be both read and written.

Router

Routes data packets within a network and between different networks via the quickest route. Can connect Ethernet networks and WLAN. Can be a Gateway to the Internet.

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