Log in to your IP Phone using the defualt username and password.

Change and update the following settings that can be found at the following page:
Advanced Settings -> Global SIP

Basic SIP Authentication Settings
Screen Name 2 = SEP Number
Phone Number = SEP Number
Caller ID = SEP Number
Authentication Name = SEP Number
Password = SEP Password

Basic SIP Network Settings
Proxy Server = End Point Server
Proxy Port = 5060
Outbound Proxy Server = End Point Server
Outbound Proxy Port = 5060
Registrar Server = End Point Server
Registrar Port = 5060

Advanced Settings -> Network

Advanted Network Settings

Rport (RFC3581) = is checked if firmware is less than 3.2


SEP Number and Password can be found in your Slingshot Dashboard under:

Team Members->Endpoints Page

Ensure that the Type is set to IP