Siemens Gigaset A580IP - Page 197

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Glossary
Gigaset A580 IP / GBR / A31008-xxxx-xxxx-x-xxxx / glossary.fm / 24.03.2010
Version 8, 03.09.2008
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 ringback function. As soon as the connection is free the
caller is rung back. As soon as the caller lifts the receiver the connection is made
automatically.
S
Server Provides a service to other Network subscribers (Clients). The term can indicate a
computer/PC or an application. A server is addressed via IP address/Domain
names and Port.
SIP (Session Initiation Protocol)
Signalling protocol independent of voice communication. Used for establishing
and ending a call. It is also possible to define parameters for voice transmission.
SIP address
£ URI.
SIP port/local SIP port
(Local) Port that is used to send and receive SIP signalling data for VoIP.
SIP
provider
£ VoIP provider.
SIP proxy server
IP address of your VoIP provider's gateway server.
Static IP address
A static IP address is assigned to a network component manually during network
configuration. Unlike a Dynamic IP address, a static IP address does not change.
STUN
Simple Transversal of UDP over NAT
NAT control mechanism.
STUN is a data protocol for VoIP telephones. STUN replaces the private IP address in
the data packets of the VoIP telephone with the public address of the secure private
network. To control data transfer, a STUN server is also required on the Internet.
STUN cannot be implemented with symmetric NATs.
£ ALG, Firewall, NAT, Outbound proxy.
Subnet Segment of a Network.
Subnet mask
IP addresses consist of a fixed network number and a variable subscriber number.
The network number is identical for all Network subscribers. The size of the net-
work number part is determined in the subnet mask. In the subnet mask
255.255.255.0, for example, the first three parts of the IP address are the network
number and the last part the subscriber number.
Symmetric NAT
A symmetric NAT assigns different external IP addresses and port numbers to the
same internal IP addresses and port numbers – depending on the external target
address.