User guide

Fundamentals114
Voice over IP (VoIP)
Create a VoIP profile with extended codec entries with the follow-
ing steps:
1. Open the Telephony: Extended: VoIP profile page in the
Configurator of the Forum 523/524 communications system.
2. Click on the Codecs button. On the following page, select the
codecs to be offered for defining a VoIP profile. Use Apply to
confirm.
The list contains entries with various classes (“audio”, “image”,
“text”, or “video”) as well as specific bandwidth information for
many entries. Particularly suitable entries are indicated as
“recommended”.
3. Click on the New button on the VoIP profile page. Enter a
designation into the Profile name input field. Determine the
permissible codecs in descending order in the 10 fields.
Configure the desired codecs from the extended codec list in
the uppermost fields. Close the list with a fall-back selection,
e.g. with “G.711 A-Law (audio)” and “DTM (RFC4733)
(event)”. Use Apply to confirm.
Allocate this VoIP profile to the desired SIP terminal or to the
desired SIP tie line. Please note that any codecs not in the VoIP
profile are filtered out by the Forum 523/524 communications
system during codec negotiation.
Voice Activity Detection (VAD)
You can change the codec configuration under Telephony:
Extended: VoIP profile. You can also activate the Voice Activ-
ity Detection option for one or more codecs in so doing. If this
option is active then pauses in the conversation will be replaced
with empty packets. This can be better compressed by compres-
sion-codecs thus reducing the required bandwidth. This option
must be deactivated if you want to assign the profile to a SIP
trunk and if you have set the G.711 codec.
Note: If you want to allocate the VoIP profile to a
Forum IPhone 512 / Forum IPhone 545 IP system telephone, the
Voice Activity Detection option should be deactivated for all
codecs.