25 April 2020

Difference between PSTN and VoIP

They are both on opposite poles when it comes to connectivity. While the VoIP provides a connection via the internet, PSTN makes use of a landline. Both flaunt their own connectivity perks and shortcomings. VoIP lets you make a call anytime and anywhere as long as you have an internet connection, One the other hand, PSTN only let you connect when you possess a landline. Here this article gives information about the difference between PSTN and VoIP are listed below.

Definition of PSTN:

PSTN stands for public switched telephone network, It uses circuit-switched telephony between two points for the duration of the call. In contrast, voice over internet protocol uses packet-switched telephony. It is the transitional telephone system that carries analog voice data via copper wires. PSTN is like a combination of telephone networks spread worldwide and this includes not just telephone lines but cellular networks, switching centers, cables systems. 

Definition of VoIP:

VoIP stands for voice over internet protocol, It transmits real-time voice signals from one IP address to another. Voice signals are transmitted in digital form over the WiFi or ethernet thought an analog adapter or a softphone. The VoIP calls can be made form one phone to another or from a computer to a phone.

Difference between PSTN and VoIP:


  • PSTN is a dedicated line while VoIP is all channels that are carried over one internet connection.
  • In PSTN each line is 64 Kbps, VoIP compression can result in 10 Kbps.
  • PSTN can be upgraded or expended with new equipment and line provisioning, while the VoIP usually requires only bandwidth and software upgrades.
  • The basic features of PSTN as call waiting, caller ID, and so on are usually available at an extra cost, While the VoIP basic features such as call waiting, caller ID, and so on are usually included free with all the service.
  • In PSTN long distance is usually per minute or bundled minute subscription, While the VoIP long distance is often included in the regular monthly price.
  • In PSTN hardwired landlines phones usually remain active during a power outage, While the VoIP is lost power, lose phone service without power backup in place.
  • When placing a 911 call it can be traced to your location via PSTN, While 911 emergency calls cannot always be traced to a special geographic location in using VoIP.

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