Siemens Gigaset C450IP User Manual

Page 90

Glossary

Gigaset C450 IP / Greek eng / A31008-M1713-T151-3-8U19 / glossary.fm / 24.9.07

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G.711 a law, G.711 µ law

Standard for a Codec.
G.711 delivers a very good voice qual-

ity that corresponds to that in the ISDN

fixed network. As there is little com-

pression, the necessary bandwidth is

approx. 64 Kbit/s per voice connection,

but the delay caused by coding/decod-

ing is only 0.125 ms.
"a law" describes the European stand-

ard and "μ law" describes the North

American/Japanese equivalent.

G.726

Standard for a Codec.
G.726 delivers a good voice quality. It is

inferior to the quality with codec G.711

but better than with G.729.

G.729A/B

Standard for a Codec.
The voice quality is rather less with

G.729A/B. As a result of the high level

of compression, the necessary band-

width is only approx. 8 Kbit/s per voice

connection, but the delay is approx. 15

ms.

Gateway

Connects two different Networks with

one another, e.g. router as Internet

gateway.
For phone calls from VoIP to the tele-

phone network, a gateway has to be

connected to the IP network and the

telephone network (gateway/VoIP pro-

vider). It forwards calls from VoIP to the

telephone network as required.

Gateway Provider

See SIP Provider.

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.

Headset

Combination of microphone and head-

phone. A headset makes handsfree

talking more comfortable. There are

headsets available which are con-

nected to the handset by a cable.

Hold music

Music on hold

Music is played while you are making

a Consultation call or Toggling.

The waiting participant hears music

while on hold.

HTTP proxy

Sever via which the Network subscri-

bers can process their Internet traffic.

Hub

Connects several Network subscribers

in one Infrastructure network. All

data sent to the hub by one network

subscriber is forwarded to all network

subscribers.
See also: Gateway, Router.