![Proximus Forum 500 Series Скачать руководство пользователя страница 161](http://html.mh-extra.com/html/proximus/forum-500-series/forum-500-series_mounting-and-commissioning-manual_1621336161.webp)
Fundamentals
Voice over IP (VoIP)
159
Channels on a
are allocated for making a telephone
connection with an ordinary terminal or for dial tones. The MGW converts IP
voice data into PCM data streams used with conventional telephony and vice
versa. For this, IP voice data are exchanged between the IP telephone and the
gateway.
Tip:
Switching between voice data channels may cause a slight delay
in some circumstances. For example: when accepting a call on an
IP telephone, headset users should wait about one second
before answering.
Useful Services
The type of data compression used for VoIP prevents these types of
connections from using certain services. Take these notes into account
especially if you want to use connections made via Q.SIG-IP or SIP:
●
ISDN data services can not be used
●
Faxes can only be sent using the uncompressed G.711 codec
●
DTMF dial tones can be transmitted using the internet standard
RFC 2833/4733 or by means of SIP-INFO. In the codec configuration
section, under
Telephony: Extended: VoIP profile
the “DTMF (RFC 4733)”
codec hast to be activated. As an alternative, DTMF dial tones can also be
transferred “Inband”. These DTMF dial tones are only received by the other
party if the uncompressed G.711 codec is used.
●
Analogue modems can not be used
Tip:
Configure the actual usage for the a/b ports, e.g. set them to
Fax
or
Data (analogue)
. Connections from and to these a/b
ports will then be made using uncompressed or ISDN connec-
tions where possible.
VoIP Profiles for SIP
While a call is being established and also during an ongoing connection, SIP
terminals can negotiate amongst one another which codecs are to be used.
SIP signalling is always being conducted via the Forum 5004/5008/5012
communications system. After successfully agreeing on a codec, the resulting
RTP connection is established between the terminals directly. The
Forum 5004/5008/5012 communications system can also serve as a proxy
Содержание Forum 500 Series
Страница 1: ...Forum 5004 Forum 5008 Forum 5012 Mounting and Commissioning Manual ...
Страница 12: ...10 ...