Make sure you have added a VoIP account in the standard SIP server.
Steps:
1. Go to SIP Settings page to select SIP protocol type: Settings -> Configuration -> SIP
Settings.
2. Select Standard Protocol.
Default admin password is 888999.
The default SIP protocol is private protocol.
Rebooting the indoor station is required when you change to Standard Protocol
from Private Protocol.
3. Set VoIP account.
The account you entered here must be the same with the account you added
in the standard SIP server.
The phone number should be a numeric, which is up to 16 digits. And the
phone number will be the number you dial when you want to call the indoor
station via standard SIP
Video Intercom Indoor Station·Quick Start Guide
Figure 4-4 SIP Protocol Selection
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