User`s guide

Vigor2850 Series User’s Guide
254
Stun – Choose this option if there is STUN server provided for
your router.
Manual – Choose this option if you want to specify an external
IP address as the NAT transversal support.
Nortel – If the soft-switch that you use supports Nortel solution,
you can choose this option.
Ring Port Set Phone 1 and/or Phone 2 as the default ring port(s) for this
SIP account.
Ring Pattern Choose a ring tone type for the VoIP phone call.
Prefer Codec Select one of five codecs as the default for your VoIP calls. The
codec used for each call will be negotiated with the peer party
before each session, and so may not be your default choice. The
default codec is G.729A/B; it occupies little bandwidth while
maintaining good voice quality.
If your upstream speed is only 64Kbps, do not use G.711 codec.
It is better for you to have at least 256Kbps upstream if you
would like to use G.711.
Single Codec – If the box is checked, only the selected Codec
will be applied.
Packet Size The amount of data contained in a single packet. The default
value is 20 ms, which means the data packet will contain 20 ms
voice information.
Voice Active Detector This function can detect if the voice on both sides is active or
not. If not, the router will do something to save the bandwidth
for other using. Click On to invoke this function; click off to
close the function.