Configuring Aastra 51i phone for 3CX Phone system

IMPORTANT This guide has been tested with firmware version 2.2.0.166. Be aware that different firmware revisions may have different web interface formats and functionality. See compatibility list for latest phone firmware revisions that we have tested with 3CX Phone System.

  1. Ensure that you have created the extension to use with the phone in 3CX Phone System. Take note of the Extension Number, the Authentication ID, and the Authentication password that you have entered for this extension.
  2. Connect the Aastra 51i phone to the network and mains power supply. The phone will boot up, and providing you have DHCP installed on your network, will obtain an IP. To find the IP, press the “Services” button on the phone and navigate to “Options”, “Phone Status” and “IP& MAC Addresses”.
  3. Now you can access the phone’s web configuration page by going to http://x.x.x.x where x.x.x.x is the IP address of the phone from step 2.
  4. The factory default username and password for accessing web configuration on Aastra phones are “Admin” and “22222”. Under “Advanced Settings” section , in “Network” page you can see that DHCP is enabled by default - configure this according to preference (refer to the screenshot below).


    Aastra 51i phone Network settings


    Aastra 51i phone Global SIP settings part 1
  5. Refer to screenshot “51i phone Global SIP settings part 1” to configure SIP.
    1. Screen Name” and “Screen Name 2” are trivial and no matter what you insert there is no direct effect on the functionality of the phone.
    2. Set the “phone number” to the extension number.
    3. Set the “Authentication Name” and “Password” to the Authentication ID and password as set in the 3CX Phone System Extension properties.
    4. Set the “Proxy server” field to the IP address or FQDN of the server on which the 3CX Phone System is installed.
    5. Set the “Proxy server” field to the IP address or FQDN of the server on which the 3CX Phone System is installed.
    6. Set the “proxy port” to 5060. Please note that if the SIP port has been changed from the default on the 3CX Phone System (in General Settings),   this value must be changed accordingly.
    7. Set the “Registrar server” and “Registrar port” to the same values as in steps a and b.
    8. Set the Registration period to a value suitable for your company. A good setting for general use could be 3600 seconds (1 hour).
    9. Click “Save Settings” to save the configuration of this page

MWI (Message Waiting Indicator) Functionality:

The 3CX Phone System can deliver MWI updates to the 51i. To use such feature, enable MWI by ticking the option “Enable” for “Explicit MWI Subscription” under the section “Advanced SIP” settings in “Global SIP” page. NOTE: This feature (MWI) is not available in the Free Version of 3CX Phone System. The MWI feature is available in all other versions.

SIP Phone Configuration Guides