Frequently asked questions
What is Linkus?
Linkus is a VoIP softphone designed to give mobile functionality to Yeastar S-Series PBX telephone systems. When Linkus is registered to an S-Series PBX, users can use Android and Apple mobile phones just like a regular office deskphone extension.
Which version of Yeastar S-Series IPPBX supports Linkus?
Linkus feature is supported on S-Series IPPBX firmware version 184.108.40.206 or later.
Which Yeastar products work with Linkus?
Linkus Mobile Client is designed for Yeastar S-Series IPPBX and Yeastar Cloud PBX.
What is the username and password for Linkus?
1. Username: the extension number.
2. Password: the extension’s “User Password”.
What is the Linkus service port?
The default Linkus service port is 8111. You can log in S-Series IPPBX web user interface, and go to “Linkus > Port Settings” to change it.
Could Linkus work in Wi-Fi network and cellular network?
When your phone is connected to the Wi-Fi network from the same router of S-Series IPPBX, the Linkus local IP address will work.
When your phone is connected to a different Wi-Fi network from S-Series PBX or connected to the mobile data, the Linkus public IP address will work.
How to make Linkus work in an external network?
To make Linkus work in an external network, you need to forward the following ports in your router:
1. Linkus service port: UDP 8111 and TCP 8111 (default)
2. SIP UDP port: UDP 5060 (default)
3. RTP ports: UDP 10000-12000 (default)
You also need to configure NAT settings in S-Series IPPBX to ensure the normal call for remote extensions. Log in Yeastar S-Series IPPBX web user interface, go to “Settings > PBX > General > SIP > NAT”, and configure NAT according to your network environment.
If I make an outbound call from Linkus, will my mobile phone pay for the call?
No, you don’t need to pay for the outbound call. The outbound call is made through S-Series IPPBX’s trunk.
Does Linkus support video calls?
Which audio codecs does Linkus support?
Now, Linkus uses iLBC codec. The iLBC codec has high quality and high robustness to packet loss. Linkus will support other codes in the later version.
Does Linkus support number rewriting?
Yes, number rewriting feature needs to work with S-Series IPPBX’s outbound route. With number rewriting feature, you can utilize your native contacts or call history numbers without having to add new entries.
Check the configuration steps below:
Step 1. Create an outbound route in S-Series IPPBX.
1. If you would like to add prefix 0, set the outbound route pattern as “”.
2. If you would like to add prefix 9, set the outbound route pattern as “”.
3. And so on.
Long press the contact’s number or the history number, choose the newly created outbound route, Linkus will add the prefix automatically and call out.
Why I cannot log in Linkus?
Please check the following settings:
1. Make sure Linkus service is enabled on S-Series IPPBX.
2. Make sure the login username and password is correct.
3. Make sure the Linkus server settings are correct.
4. If you are trying to log in Linkus in an external network, please make sure the Linkus port is forwarded.
Why there is no audio in Linkus call?
Please check the following settings:
1. Make sure the SIP RTP ports are forwarded.
2. Make sure the configuration on Yeastar S-Series IPPBX NAT page is correct. (Settings > PBX > General > SIP > NAT)
Can I log in Linkus using a domain?
Yes, Linkus supports logging in using a domain. However, due to possible DNS resolution delay, we suggest that you use a static IP address to ensure the network stability.
After making a one-touch record on Linkus, where can I check the recording file?
You can download and play the recording file on Linkus directly. Go to “Me” -> “Recording” to check your recording files