SIP Trunking in AVOXI (Outbound Termination / Making Calls)

Easily integrate your current in-house PBX or third-party platform (example: MS Teams) with your AVOXI online platform, and instantly enable outbound calling to any destination around the world. Available to all AVOXI users at no additional cost, SIP Trunking is a popular solution for businesses looking to cut local and long-distance calling costs without having to replace an existing system. 

Use the below quick links to view, manage and configure SIP Trunking within your AVOXI online portal.

SIP FORWARDING:  Use the following SIP Forwarding Guide to setup SIP URI's (SIP Forwarding - Inbound Forwarding) 

Viewing and Adding SIP Trunk(s)

Adding a SIP Trunk

Use the below step-by-step guide to add and configure your SIP Trunks

  • To get started navigate to the SIP Trunk section located on the left-hand navigation bar.
  • Select the "SIP Trunks" tab
  • Click the "Add SIP Trunk" button

Name your SIP Trunk 

Give your SIP Trunk a friendly name using letters, spaces, and numbers. This is the name that will appear under the "Usage" section in the "Account ID" column of your monthly invoice.

  • Special characters are not accepted
  • Max name length allowed length is 116 characters

SIP Connection

  • Select how you would like to terminate your outgoing traffic (for example MS Teams to or Regular SIP Trunk).

Authentication Type 

Method of authentication to ensure outbound calls through the SIPTrunk can be uniquely authorized.


  • Enter your Username and Password
  • Ensure that the username matches the From header user or the To header user 


  • Enter one or more required IP Address
  • If this is a shared platform, please provide additional information for authentication, such as the SIP header or username/secret on top of the IP address. 


Not everyone can support Basic Authentication from a shared platform.  In this case, you will need a SIP Header, which means you can add a special header and value to the message to prove the message is yours.   

  • Header Name:  Add special header name for SIP invite
  • Header Value:  Add the special header value for the SIP invite
  • Protocol: Select your ideal transport protocol
  • SIP Invite Message ExamplesConsider the following SIP message as an example:
    • INVITE SIP/2.0
      CSEQ: 1 INVITE
      From: “Alice” <sip:+>
      To: Bob <>
      Max-Forwards: 67
      Date: Wed, 14 Jul 2021 17:58:47 GMT
      Min-SE: 120
      Call-ID: 12345678
      P-Asserted-Identity: “Alice” <>
      Contact: “+14049375037” <;transport=udp>
      User-Agent: Awesome Customer PB
      Content-Type: application/sdp
      Content-Length: 276

  • Header Authentication - Below is a list of headers, we do not check for header authentication
    • Via
    • Too
    • Call-ID
    • CSeq
    • Contact
    • Max-Forwards
    • Allow
    • Supported
    • User-Agent
    • Content-Type
    • Min-SE
    • Content-Lenght
    • Record-Route
    • Proxy-Authorization
    • Allow-Events

When ready, select the "Add New SIP Trunk" button to complete.

Configuration Details

Now you have added your SIP Trunking to your AVOXI account, it is important to configure it on your communications infrastructure/platform.


US POP Send Calls to:

Hong Kong POP Send Call to:


Open your firewall to the following IP's:



AVOXI supports UDP, TCP, and TLS(SRTP) version1.2 (follow here to learn more).  Open the following ports to ensure proper connectivity:

  • 5060 UDP
  • 5060 TCP
  • 5061 TLS


AVOXI supports the below Codecs 

  • G.711u(ulaw), 
  • G.711a(alaw), 
  • G.729


  • RTP port range for AVOX10000-65535
    • If configured, both TLS and SRTP are used to encrypt calls between you and AVOXI. TLS/SRTP can be used for both inbound and outbound voice services (Originating and Terminating). 
    • As an AVOXI Administrator you are required to download and manually load the certificate during the configuration process to ensure the TLS connection are made (example 
  • Media IP Addresses

Configuring Third-Party Platforms 

Use the below quick links to view the relevant configuration guide:

Note: Each SIP Trunk can have a different Authentication Type, meaning you can have several SIP Trunks with different authentication types.  However, when configuring an individual SIP Trunks you can only select one authentication type.

Downloading SIP URI TLS Certificate

Transport Layer Security (TLS) certificates, also known as Secure Sockets Layer (SSL), work the same as HTTPS and are crucial for securing internet browser connections through data encryptions.  Similar to HTTPS when a browser tries to connect using TLS the secure web certificate is sent. As a customer, you can configure and manage the TLS/SRTP within your AVOXI online portal. Certificates are used for authentication and encryption.  

There is an SSL (TLS) certificate for  used for calls coming from the user to the AVOXI Genius platform, and for calls leaving AVOXI Genius.  As an AVOXI Administrator you are required to manually load the certificate during the configuration process to ensure the TLS connection are made (example  

Use the below steps to download the required certificate file from within your AVOXI online application.

  • Navigate to the SIP Trunks section located on the left-hand navigation bar.
  • Click on the SIP URIs tab.
  • Select the three buttons located to the right of the "+Add" button
  • Simply click on the "Download SIP URI TLS Certificate

Call Recording

Calls will only record if the call recording feature has been enabled at an organizational level.  As an Administrator, you can easily manage your business call recording settings within your online platform.  Use the following self-help guide to turn your recording on/off, and manage retention settings.  When deleting a SIP Trunk this will not delete the call recordings.

To learn more about SIP Trunking view our The Beginner's Guide to SIP Trunking and SBC Solutions

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February 10th, 2022


Criss Soto

Updated By:

Louise Ross



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