Gigaset C470 IP Manual page 182

Glossary
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).
Full duplex
Data transfer mode in which data can be sent and received at the same 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 con-
nection, but the delay caused by coding/decoding is only 0.125 ms.
"a law" describes the European standard and "µ law" describes the North American/Jap-
anese 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 trans-
fer rate of 64 kbit/s per language 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 bet-
ter voice quality than other codecs and enables a speech tone in High Definition Sound
Performance (HDSP).
G.726
Standard for a Codec.
G.726 delivers a good voice quality. It is inferior to the quality with codec G.711 but bet-
ter than with G.729.
G.729A/B
Standard for a Codec.
The voice quality is rather lower with G.729A/B. As a result of the high level of compres-
sion, the necessary bandwidth is only around 8 kbit/s per voice connection, but the
delay is around 15 mins.
Gateway
Connects two different Networks, e.g. a router as an Internet gateway.
For phone calls from VoIP to the telephone 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 SIP provider.
Global IP Address
See IP address.
GSM
Global System for Mobile Communication
Originally, European standard for mobile networks. GSM can now be described as a
worldwide standard. In the USA and Japan national standards are now more frequently
supported than in the past.
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