Seizing PSTN Line Faster

There is a phenomenon that when making outgoing call through PSTN trunk on Yeastar S-Series IPPBX and it takes about several seconds before the call is established to the destination number (e.g. Mobile). Is there any way we can improve this? Can we seize the PSTN line more quickly?


General seizing PSTN line method

Creating an outbound route with settings as below, selecting PSTN lines and setting Dial Pattern as “9.”‘ and Strip as "1". Please noted that 9. is an example and the client can set as 8. and others.

1) Dial 9 to seize line, and when you heard the dial tone which will take around 1.7 seconds, and it means Yeastar S-Series IPPB had already seized the PSTN line.


2) Dial the numbers according to your needs.


Improved Seizing PSTN line method

Yeastar S-Series IPPBX can seize the PSTN line immediately and reduce the client waiting time using this method. As the below scenario shown, 501 dial 9 (or dial 9# for faster according to the client needs). Then dial 18756983326 till you heard the dial tone. More operation please check the below steps.


  • Set the outbound route for the last PSTN line.__15.png
  • Set DISA for the Outbound route “PSTN_outbound”.__16.png
  • Create loop trunk, which function is let the outgoing requests back to S series itself.__17.png
  • Set the outbound route for trunk And please noted that we take 9 to seize PSTN line as an example here.__18.png
  • Set the inbound route for trunk
Have more questions? Submit a request


Please sign in to leave a comment.