Billion 800VGT Router
Advanced – Parameters
VoIP through IP Interface: IP Interface decides where to send/receive the VoIP traffic. Options include: ipwan and iplan. An easy way to select the interface option is to check the location of the SIP server. If it is located somewhere on the Internet, then select ipwan. If the VoIP SIP server is on the local network then select iplan.
Voice Frame Size: Voice Frame size can be set anywhere between 10ms and 60ms. The function of Voice Frame Size is how many milliseconds the Voice packets will be queued for, before being sent out. Billion 800VGT Router
The ideal setting is to have the same frame size for both Caller and Receiver.
PSTN
Click Edit to add or remove codes. Be sure that the codes are separated by a comma(,).
For more information about SIP response codes, please click on 
to link to
Advanced – PSTN Environment Adjustment
The PSTN Environment Adjustment options will help you to adjust the on hook and off hook voltage detection values for your environment. The actual levels are determined by your environment including the number and type of telephones used. The default values provided are suitable for the South African PSTN network, and there should not be modified. If, however, you are connecting the line port to a PABX, and you experience problems with placing calls, then you may wish to modify these parameters.
Note: ON HOOK means hung up.
To take your phone OFF HOOK, lift the receiver then press Hook/Flash until you hear your normal PSTN dial tone, not your VoIP dial tone. Wait several seconds and then press Check Level.
You should check the OFF HOOK value for each telephone you have connected to this device. Set the OFFHOOK voltage to the lowest setting registered for all your telephones, e.g. if your telephones return values of 4, 5 and 7 then you should set your OFFHOOK voltage to 4.
Note: The detected values will not automatically be set by the Check Level function; you must enter the lowest level detected after testing all your telephones.
