Draytek Vigor2130 series User Manual page 237

Codecs
Default SIP Account
After finished the above configuration, click OK to save the settings and exit this page.
Vigor2130 Series User's Guide
notice sound will appear to tell the user new phone call is
waiting for your response. Click hook flash to pick up the
waiting phone call.
Call Transfer- Check this box to invoke this function. Click
hook flash to initiate another phone call. When the phone
call connection succeeds, hang up the phone. The other two
sides can communicate, then.
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 Detection- 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.
You can set SIP accounts (up to six groups) on SIP Account
page. Use the drop down list to choose one of the profile
names for the accounts as the default one for this phone
setting.
Play dial tone only when account registered - Check this
box to invoke the function.
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