Draytek Vigor2760 series User Manual page 305

change SIP account for each phone port.
DTMF Relay – Display DTMF mode that configured in the
advanced settings page of Phone Index.
RTP Symmetric RTP – Check this box to invoke the function.
To make the data transmission going through on both ends
of local router and remote router not misleading due to IP
lost (for example, sending data from the public IP of remote
router to the private IP of local router), you can check this
box to solve this problem.
Dynamic RTP Port Start - Specifies the start port for RTP
stream. The default value is 10050.
Dynamic RTP Port End - Specifies the end port for RTP
stream. The default value is 15000.
RTP TOS – It decides the level of VoIP package. Use the
drop down list to choose any one of them.
After finishing all the settings here, please click OK to save the configuration.
293 Vigor2760 Series User's Guide