When configuring a phyical device it may be neccessary to pay close attention to the device settings, which are often optimised for connection to particular phone systems / PBX's.   If incorrect settings are used this can affect the device's ability to make or receive calls.  It is not possible to list configuration for all SIP devices but below are a list of common settings that should be checked and correctly set:

1. Basic device settings:

These are the core settings required to authenticate a device.  It is likely that just setting just these parameters is all that is required in order to correctly configure and use your device with 4HA.

'Account' / 'Authentication User Name' should be set to the 4HA device 'SIP' > 'Username'

'Registrar' / 'Proxy' / 'Outbound Proxy' should be set to the 4HA device 'SIP' > 'Realm'

'Password' / 'Authentication Password' should be set to the 4HA device 'SIP' > 'Password'

2. Advanced device settings:

In addition to the basic settings, it may be necessary to review other device settings that can impeded correct connectivity and affect the device's ability to make / recieve calls.

'Support Broken Registrar' should be set to 'On' (e.g. on a Snom 720 handset this setting is found in the web interface under 'Setup' > 'Identity 1' > 'SIP')

'Server Type' should be set to 'TAHI' for some Snom handsets (dependent upon the Snom phone versions)

'SIP-INFO Signalling' should be set to 'RFC2833' (not to 'DTMF')