BT Micro - Page 121

BT Micro Owner’s Manual
121
You can change the VoIP settings by selecting Change
Advanced VoIP settings here. These should not normally be
changed.
Registrar Server Port
The registrar server port may be any value between 1 and
65535. It is the port used by the SIP proxy server.
Registrar Server Expiry Time
The SIP registrar server expiry time interval can be any number
between 1 and 86400. The timer is in seconds, and sets the
frequency with which BT Micro refreshes its registration with the
SIP proxy server.
Transport for Invite Requests
The transport for SIP invite requests may be either TCP or UDP
Preferred Codec
The following codecs are supported on the system:
G.729
G.711
G.726.
Definition
A Codec (Coder/Decoder) converts analogue voice signals into
digital signals for transmission over the IP network.
Use this field to select the type of voice codec that you want the
system to use. The choice of voice codec is a trade-off between
transmission speed, sound quality and desired bandwidth usage.
The G.711 codec provides higher voice quality than G.729 but
requires 82.8kbps of bandwidth as opposed to 26.8kbps for
G.729. The system can connect to other VoIP systems that use
the same codec.
Backup Codec 1
This field specifies the first backup codec to use in the event
that the far end does not support the Preferred Codec.