Use Yeastar Cloud PBX with PSTN/POTS (RJ11)

What if you want to use your PSTN/POTS copper telephone lines (so that your office number remains) with a Cloud PBX and IP Phones? Only Yeastar has a solid solution for this.

The PSTN is the original, analog landline telephone network, and is also known as plain old telephone service (POTS). Very often you will see these cables at Singapore offices.

  • RJ-11: It’s for your office telephone lines.
  • RJ-45: It’s for your office internet network.


It might be just the right time to learn more about VoIP technology and SIP trunking: the largest telecom providers all around the world stop offering ISDN and PSTN in 2018 and have announced complete phasing-out over the next ten years. Regardless if you want to move to SIP trunk or not, there will be no more PSTN copper telephone lines before year 2030. 

Is it too early to move to SIP trunk? To some customers who are still using PSTN, the answer would be “Yes, it’s too early, there are still 10 years to go”, because many of them do not want to change status quo:

  • Mentally, people are used to PSTN for decades, most of the time it’s stable, so why not just continue to use it.
  • Technically, traditional analog phone lines can’t be plugged into your IP network anyway.
  • For now, local Telco has made the number porting difficult, occasionally a customer may risk losing their number during the porting process.


What if you still want to use your PSTN/POTS copper telephone lines, you just like the unified communication idea, and want a Cloud PBX and IP phone solution?

Introducing Yeastar’s FXO to VoIP gateways:


Yeastar TA410


Here is the configuration topology:

What you are going to do with an FXO gateway:

  1. Configure a SIP trunk to interconnect FXO gateway and Yeastar Cloud PBX.
  2. Configure outbound routes from Cloud PBX to FXO gateway, then from FXO gateway to PSTN/POTS.
  3. Configure inbound routes from PSTN/POTS to FXO gateway, then from FXO gateway to Cloud PBX.


Now, your PSTN/POTS lines are officially connected to our Yeastar Cloud PBX, all Yeastar Cloud PBX’s advanced features and Linkus UC will be made available to you, using your existing PSTN phone lines.

There are many things you can do with our Cloud PBX, such as:

  • Everything you want to achieve with a phone system will be made available to you and manageable online. (Basic usages: call forward, voicemail, call recording, chat, status, etc)
  • You will have better mobility with Linkus
  • You can easily integrate with CRM, or connect to call center statistics software.

More information can be found on our website, alternatively, just contact us for a faster answer or request a quotation from us.

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