Set up a Remote SIP Phone via Public IP Address and Port

This topic provides a configuration example to help you understand how to register a remote SIP extension on a SIP phone using public IP address and port of the PBX.

Background information

Yealink T56A and Yeastar P-Series Software Edition are in different locations and networks. The administrator wants to register Yealink T56A on Yeastar P-Series Software Edition, so that users in branch office can use Yealink T56A to make and receive calls.


Step1. Forward the required ports on your router

Forward the following ports on Router 2 that is connected to Yeastar P-Series Software Edition, so that all the packets received on the router WAN port ( can be forwarded to the PBX (

Table 1.
Service port Local port External port
SIP Registration Port UDP 5060 UDP 5078
RTP Ports Range UDP 10000-12000 UDP 10000-12000

Step2. Configure SIP NAT settings on your PBX

Configure SIP NAT settings to ensure that SIP data can be transmitted correctly between the PBX and the public Internet.
  1. Log in to PBX web portal, go to System > Network, click Public IP and Ports tab.
  2. Turn on the option Public IP (NAT), and configure NAT settings.
    1. In the NAT Type drop-down list, select Public IP Address.
    2. In the Public IP address field, enter the PBX's WAN IP. In this example, enter
    3. In the Local Network Identification section, enter the local network segment and subnet mask.
      1. Click +Add IP.
      2. In the Network Number field, enter the LAN IP. In this example, enter
      3. In the Subnet Mask field, enter the subnet mask. In this example, enter
    4. In the NAT Mode drop-down list, select Yes.

      The PBX uses NAT, ignores the address information in the SIP headers or SDP headers, and replies to the sender's IP address and port.

  3. Enter external ports that you have forwarded on the router 2.
    • External SIP UDP Port: In this example, enter 5078.
  4. Click Save and Apply.

Step3. Set up an extension for remote access

  1. On the PBX web portal, go to Extension and Trunk > Extension, edit the desired extension.
  2. Click Security tab, select the checkbox of Allow Remote Registration.
  3. Click Save and Apply.

Step4. Register the extension on the phone

Log in to the phone web interface to register the desired extension on Yealink T56A.
Note: Use the public IP address of the PBX and the forwarded SIP port to register the remote extension.


Users in branch office can use Yealink T56A to make and receive calls.