Configuration
37
Command key ............ When using the telephone as a system telephone
the function keys will be programmed by the tip-
tel.com telephone system.
When using your tiptel 83 VoIP as a system telephone at a tiptel.com telephone sys-
tem you should programme the function key mode to "command key" in order to
enable the telephone system to programme those keys.
General SIP settings
WEB
→
VoIP Phone Menu
→
Phone Setting
→
DSP Config
For voice quality and bandwidth (data volume) optimization you can modify the fol-
lowing settings:
Codecs......................... Preferred codec for voice calls. The codec will be
negotiated at the start of each connection set-up.
This means that also codecs different from the ones
you programmed can be used. This happens when
the other party's telephone does not support the
codec you programmed.
G.711
Voice quality similar to ISDN, highest
bandwidth
A-law: Flavour mainly used in Europe
µ-law: Flavour mainly used in North
America and Japan
G.723
Slightly Reduced voice quality with
less bandwidth
r63 – 6.3 kbps (+ overhead!)
r53 – 5.3 kbps (+ overhead!)
G.729
Good voice quality with less band-
width
G.729 Packet size ....... The smaller the size the smaller the delay times and
the lower the gaps during packet loss. With bigger
packets, however, the protocol overhead will be re-
duced resulting in much lower bandwidth need in
particular with codecs different from G.711.
