Siemens Gigaset A580 IP User Manual page 182

Billing system for an
Flat rate
monthly fee. There are no additional charges for the duration of the connection
or number of connections.
Fragmentation
Data packets that are too big are split into smaller packets (fragments) before
they are transferred. They are put together again when they reach the recipient
(defragmented).
Data transmission is a mode in which data can be sent and received at the same
Full duplex
time.
G
G.711 a law, G.711 µ law
Standard for a Codec.
G.711 delivers a very good voice quality that corresponds to that in the ISDN
fixed line. As there is little compression, the necessary bandwidth is around 64
kbit/s per voice connection, but the delay caused by coding/decoding is only
0.125 ms.
"a law" describes the European standard and "µ law" describes the North Amer-
ican/Japanese equivalent.
G.722 Standard for a Codec.
G.722 is a broadband language codec with a bandwidth of 50 Hz to 7 kHz, a
net transmission rate of 64 kbit/s per voice connection and integrated speech
pause recognition and comfort noise generation (silence suppression).
G.722 delivers very good voice quality. A higher sampling rate provides clearer
and better voice quality than other codecs and enables a speech tone in High
Definition Sound Performance (HDSP).
Standard for a Codec.
G.726
G.726 delivers a good voice quality. It is inferior to the quality with codec G.711
but better than with G.729.
Standard for a Codec.
G.729A/B
The voice quality is more likely to be lower with G.729A/B. As a result of the
high level of compression, the necessary bandwidth is only around 8 kbit/s per
voice connection, but the delay is around 15 ms.
Connects two different Networks, e.g. a router as an Internet gateway.
Gateway
For phone calls from
nected to the IP network and the telephone network (gateway/VoIP provider).
It forwards calls from VoIP to the telephone network as required.
Gateway provider
£
SIP provider.
Global IP address
£
IP address.
Internet connection. The Internet provider charges a set
VoIP to the telephone network, a gateway has to be con-
Glossary
181