There are many scenarios where you may want to manually configure a phone or a softphone to the PBX.For a phone/softphone to be compatible with the PBX, it must be SIP-based and support both 'domain' and 'proxy.' Domain and Proxy may be named differently in the phone's configuration. Some example alternatives: 'Registrar,' 'Host,' 'Server,' 'Outbound-Proxy.'Add a softphone in the PBX PortalTo configure a phone extension where the SIP Credentials are visible, browse to the 'Edit Phones' page for the user in the PBX Portal.Please see the article about reserved extension suffixes to avoid any conflicts.'Add Phone' Leave the Model as 'Select a Phone Model,' then 'Add'.You will only have the option to enter a Phone Extension Suffix if the primary extension does not exist (1005 would need to exist to be able to add 1005a).The phone extension will then be visible on the page but, in some cases, will require a page refresh.'Edit' on the phone to see the required credentials to register a phone. The 'Model' drop-down box will now show 'Manual or Softphone.'These credentials should all be required to register and make calls from a phone or softphone, but additional phone configuration will vary depending on the client.