171
Glossary
Gigaset DX800A all in one / GRC EN / A31008-N3100-T101-1-7619 / Glossary.fm / 31.08.10
V
e
rsion 4, 16.0
9
.2005
G
G.711 a law, G.711 μ law
Standard for a
.
G.711 delivers a very good voice quality that
corresponds to that in the ISDN network. As
there is little compression, the necessary
bandwidth is around 64 kbit/s per voice con-
nection, but the delay caused by coding/
decoding is only approx. 0.125 ms.
"a law" describes the European standard and
"μ law" describes the North American/Japa-
nese equivalent.
G.722
Standard for a
.
G.722 is a
broadband
language codec with a
bandwidth of 50 Hz to 7 kHz, a net transmis-
sion rate of 64 kbit/s per voice connection
and integrated speech pause recognition
and comfort noise generation (silence sup-
pression).
G.722 delivers very good voice quality. A
higher sampling rate provides clearer and
better voice quality than with other codecs
and enables a speech tone in High Definition
Sound Performance (HDSP).
G.726
Standard for a
.
G.726 delivers a good voice quality. It is infe-
rior to the quality with codec
G.711
but bet-
ter than with
G.729
.
G.729A/B
Standard for a
.
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.
Gateway
Connects two different
,
e.g., a router as an Internet gateway.
For phone calls from
network, a gateway has to be connected to
the IP network and the telephone network
(gateway/VoIP provider). It forwards calls
from VoIP to the telephone network as
required.
Gateway provider
See
.
Global IP address
See
GSM
Global System for Mobile Communication
Originally, a European standard for mobile
networks. GSM can now be described as a
worldwide standard. However, in the USA
and Japan, national standards were previ-
ously more frequently supported.
H
Headset
Combination of microphone and
headphone. A headset enables a
comfortable hands free mode. Headsets that
can be connected to the base via a cable
(wire-bound) or via Bluetooth (wireless) are
available.
HTTP Proxy
Server via which the
can process their Internet traffic.
Hub
Uses one
to connect
. All data sent to
the hub by one network subscriber is for-
warded to all network subscribers.
,
.