The following configuration guide will be help with configuring these phones with sipgate basic:
Mitel 6863i, 6865i, 6867i, 6869i
If you're purchasing a new IP Deskphone we recommend Gigaset, Snom and Yealink Deskphones: What types of VoIP phones and devices can I use?
Follow the instructions in your phone's manual to access your Aastra's Web Configuration menus.
To configure your phone you'll need your SIPID and SIP Password.
Follow the instructions in the manual to open your phone's Web Interface.
Advanced Settings->Line N:
Advanced Settings -> Global SIP:
The audio codecs supported by sipgate are listed here.
To test your configuration please see this Help Article:
Testing your VoIP Phone's Configuration
If you run into issues registering your phone online, with placing calls, or with audio quality the following Help Articles offer useful troubleshooting advice: