Configure the listening port in Exchange Online

You can configure the TCP port that's used to listen for Session Initiation Protocol (SIP) requests on a Unified Messaging (UM) IP gateway. By default, when you create a UM IP gateway, the TCP SIP listening port number is set to 5060. The TCP SIP listening port can't be configured or changed by using the EAC. You must configure the TCP SIP listening port number by using the Set-UMIPGateway cmdlet.

You may have to configure the TCP listening port number to 5061 if you want to:

  • Set the VoIP security setting on a UM dial plan to SIP Secured.

  • Set the VoIP security setting on a UM dial plan to Secured.

  • Integrate with Microsoft Office Communications Server 2007 R2 or Microsoft Lync Server.

  • Use mutual Transport Layer Security (mutual TLS) to encrypt network data between Exchange servers and a VoIP gateway, Private Branch eXchange (PBX) enabled for SIP, IP PBX, or session border controller (SBC).

If you want to use mutual TLS between a UM IP gateway and a dial plan operating in either SIP Secured or Secured mode, when you create the UM IP gateway you must configure it with a fully qualified domain name (FQDN) and then use Exchange Online PowerShell to configure the UM IP gateway to listen on TCP port 5061. You must also verify that any VoIP gateways, PBXs enabled for SIP, IP PBXs, and SBCs have also been configured to listen for mutual TLS requests on port 5061.

Important

When you create a UM IP gateway using an FQDN, you must create the appropriate HOST (A) records in your DNS forward lookup zone. If you create a UM IP gateway using an FQDN, and the DNS configuration for the UM IP gateway is changed, you must disable and then enable the UM IP gateway to make sure that the UM IP gateway's configuration information is updated correctly.

For additional management tasks related to UM IP gateways, see UM IP gateway procedures.

What do you need to know before you begin?

  • Estimated time to complete: 2 minutes.

  • You need to be assigned permissions before you can perform this procedure or procedures. To see what permissions you need, see the "Unified Messaging" entry in the Feature permissions in Exchange Online topic.

  • Before you perform this procedure, confirm that a UM dial plan has been created. For detailed steps, see Create a UM dial plan.

  • Before you perform this procedure, confirm that a UM IP gateway has been created. For detailed steps, see Create a UM IP gateway.

  • For information about keyboard shortcuts that may apply to the procedures in this topic, see Keyboard shortcuts for the Exchange admin center.

Tip

Having problems? Ask for help in the Exchange forums. Visit the forums at Exchange Online or Exchange Online Protection.

Use Exchange Online PowerShell to configure the TCP listening port

This example configures a UM IP gateway named MyUMIPGateway that has an FQDN of mTLS.MyUMIPGateway.contoso.com and listens for SIP requests on TCP port 5061.

Set-UMIPGateway -Identity MyUMIPGateway -Address mTLS.MYUMIPGateway.contoso.com -Port 5061

This example configures a UM IP gateway named MyUMIPGateway that has an FQDN of SIPSecured.MyUMIPGateway.contoso.com and listens for SIP requests on TCP port 5061.

Set-UMIPGateway -Identity MyUMIPGateway -Address SIPSecured.MyUMIPGateway.contoso.com -Port 5061

This example configures a UM IP gateway named MyUMIPGateway that has an FQDN of MyOCSUMIPGateway.contoso.com and listens for SIP requests on TCP port 5061.

Set-UMIPGateway -Identity MyUMIPGateway -Address MyOCSUMIPGateway.contoso.com -Port 5061