Registering a PBX

There are a few steps to follow before you register your local PBX to Nextiva's SIP Trunking servers.

  1. First, create a device within your Nextiva SIP Trunking Portal. Creating a device will generate a unique set of authentication details necessary for the PBX to register with Nextiva. Each device creates a unique call path for routing purposes.
  2. Log in to the Nextiva Trunking Portal by going to and selecting Login at the top of the page. Enter your login credentials and click Sign in.
  3. When creating the device within the portal, you will be asked to fill out information regarding the address where this device is located. This is critical as it is generating the E911 information associated with your local PBX.
  4. Once you finish filling out the E911 information you will be asked to choose from one of two options to create the Authentication Details. We recommended using the Randomly Generate option.
  5. This applies to the authentication details necessary for your local PBX to register or authenticate with Nextiva’s SIP trunking servers.


Now that the authentication details have been generated, you may register your local PBX to Nextiva’s SIP trunking servers by using the following information.

  • Example of a Registration String:

As each local PBX’s web interface and infrastructure will vary, there may be other details necessary to ensure that the PBX is fully functional. The registration information above details the core requirements necessary to register your PBX.

Note: Other peer details may be necessary to ensure that the PBX is registered and functional, but here is a starting list:

  • Disallow=all
  • Allow=ulaw
  • Username=AUTHORIZATIONNAME (replace with the values generated from Trunking Portal)
  • Fromuser=AUTHORIZATIONNAME (replace with the values generated from Trunking Portal)
  • Type=friend
  • Secret=AUTHORIZATIONKEY (replace with the values generated from Trunking Portal)
  • Qualify=no
  • Maxexpirey=3600
  • Insecure=invite
  • Dtmfmode=auto
  • Session-timers=refuse
  • Defaultexpirey=60
  • Nat=no
  • Canreinvite=no
  • Context=from-trunk


Create an Outbound Route for where you want the Trunk to be accessed:

NOTE: Nextiva’s system will control the outbound caller ID. Please use the Authentication Name of your trunk for any fields asking for CID number.

  1. Route Name: A descriptive name for the route
  2. Outbound CID: AUTHORIZATION NAME (replace with the values generated from Trunking Portal)
  3. Dial Patterns: Typically, select all dial patterns except information. (Directory services are not supported through Nextiva SIP Trunking)
  4. Trunk Sequence: Choose the name of the Trunk you created


Create an Inbound Route for the DID of the Trunk:

o Select from the “Inbound Routes” section of your PBX and input the following information:

  • DID NUMBER: AUTHORIZATION NAME (replace with the values generated from Trunking Portal)

With this information, you should be able to register and provision your local PBX. If this does not work, enter the authentication details into a computer or mobile application like 3CX and attempt to make a call. If the call is successful, the PBX Administrator will need to troubleshoot the PBX settings, as the Nextiva side of the configuration was completed successfully. 

Note: While Nextiva supports many different types of SIP Trunking devices we offer limited support regarding the physical application of entering the following information into the PBX. If you are experiencing challenges registering your PBX please contact the manufacturer of your PBX and provide the criteria listed above.

To contact our support team please email us at, Submit a Ticket, or give us a call at 800.285.7995.

Updated on May 7, 2018

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