Hosted SIP Phones with Local Survivability Sample Configuration

Version 16

    Hosted SIP Phones with Local Survivability Sample Configuration

    The sample configuration below contains the options needed for local survivability of hosted SIP phones registered through the AOS SIP Proxy.  For the below sample configuration, the following is assumed about the application:

    • IP interfaces, routing, and firewall features not referenced in this document have already been enabled.
    • The SIP phones register to their SIP server using ten digit numbers (i.e. 256-555-1234), but the application requires local SIP phone to SIP phone calls be made using the last four digits of the phone number during survivability (i.e. 1234).

    The following are key notes regarding the application:



    • The SIP phone facing IP address of the AOS device will need to be configured as the phones’ default gateway and DNS server.
    • The AOS device will be configured to act as a DNS proxy, which is required during survivability when a FQDN is used for the provisioning server, SIP server, outbound proxy, or registrar. The command voip name-service host <FQDN> sip udp ensures that the specified FQDN persists even when connectivity to the unit’s DNS server has been lost.  An entry will need to be made for every FQDN the SIP phones are configured for, whether that be for provisioning or to send SIP traffic to . If a phone fails to resolve a FQDN, the phone will potentially not boot up , register or make/receive phone calls .
    • The ADTRAN can be configured to allow the registration of SIP phones during failover with the sip proxy failover accept-registrations command. This configuration command is desirable if the end users reboot their phones during survivability. When choosing whether or not to use this command, be aware that the command opens the unit up to accept ALL registrations during survivability.  This means that any rogue SIP device on the LAN can register to the unit during survivability and make calls to other SIP proxy users.


    Additional Resources:


    domain-proxy failover

    domain-lookup database local



    ip dhcp pool “PHONES”





      timezone-offset -6:00


    interface eth 0/2

      ip address

      ip access-policy PHONES

      media-gateway ip primary

      no shutdown



    sip proxy

    sip proxy transparent


    sip proxy failover accept-registrations


    sip proxy failover match-digits 4


    voip name-service host sip udp

    voip name-service host sip udp