Configuring your Voxtelesys SIP trunk with the Grandstream UCM6300 Series PBX is easy, follow the simple steps below to register your SIP trunk, once registered you can create your inbound and outbound rules to send and receive calls!
Go to the "Extension/Trunk" tab, then click on "VoIP Trunks" from the drop-down menu.
Click on the "+ Add SIP Trunk" button.
Click on the edit icon.
Click on the "Advanced Settings" button.
Update the following codecs to PCMU, PCMA, and G.729 and click on the "Save" button.