XonTel S200 Administrator's Guide
www.sahabtec.com
Page93
Yes = Use NAT. Ignore address information in the SIP/SDP headers and reply to
the sender's IP address/port.
No = Use NAT mode only according to RFC3581.
Never = Never attempt NAT mode or RFC3581 support.
Route = Use NAT but do not include rport in headers.
·Allow RTP Reinvite
By default, the system will route media steams from SIP endpoints through
itself. Enabling this option causes the system to attempt to negotiate the
endpoints to route packets to each other directly, bypassing the system. It is not
always possible for the system to negotiate endpoint-to-endpoint media
routing.
3
)
Codecs
Figure 6-55
A codec is a compression or decompression algorithm that used in the
transmission of voice packets over a network or the Internet.
u-law:
A PSTN standard codec, used in North America, that provides very
good voice quality and consumes 64kbit/s in each direction (receiving and
transmitting) of a VoIP call.
a-law:
A PSTN standard codec, used outside of North America, that
provides very good voice quality and consumes 64kbit/s in each direction
(receiving and transmitting) of a VoIP call.
GSM/UMTS:
A wireless standard codec, used worldwide, that provides
adequate voice quality and consumes 13.3kbit/s in each direction (receiving
and transmitting) of a VoIP call. GSM/UMTS is supported by many VoIP
phones.