POTS Lines stands for Plain Old Telephone Service which are the analog copper services that have been in every business and residential home for 100 years. ¬†It is part of the Publicly Switched Telephone Network (PSTN) which supports routing calls from the origination to destination. ¬†Over time, many features were introduced by telephone providers such as voice mail, caller id, call waiting, 911, and more. ¬†Many telecom professionals and consumers of these services also define POTS as ‚Äúlandlines‚ÄĚ which provide unique slang.


If you are old enough to remember when AT&T was the only phone provider in the United States, you may recall having one of these black rotary phones.  Prior to the US Government’s breakup of AT&T, they were the only option for telephone service.  Once AT&T broke apart and other ILEC and CLECs began to emerge for competitive pricing for businesses, they continued the tradition of copper analog installations.

AT&T Phone


POTS lines were much easier to install at a business because most likely the building had been pre-wired with a 66-block in the basement to support any needed lines.  Additionally, power was not required to support calls as the telephone itself received the necessary signaling, so simple wiring to a desk made turnups easy.

66 Block


POTS lines have not gone away, there are still many carriers who will provide the service, usually if the building had copper service prior.  The FCC has now allowed carriers to apply for relief in the traditional POTS dial-tone requirement with the advent of new technology, namely VOIP and Cellular.  You can read more about FCC 19-72 here.  Some proponents hail VOIP as the better alternative compared to these legacy analog lines and we would argue it all depends on the use case.

How do POTS Lines work

POTS lines have gone through a few iterations since Alexander Graham Bell began placing calls.  Calls are sent out and received from the receiver, which connects to a Terminal that is routed to a Central Office (CO).  Every town has at least one if not more COs and major cities could have hundreds.  The Central Offices today have transformed as well to become more of mini Points of Presence (POPS) where they terminate SDWAN, Internet, Private Line, VOIP, and other services.  That’s for another read & blog for a different day!

Once the call lands in a CO, there will be a quick determination if this call is local to the CO (say your neighbor’s house) or if it’s going cross-country or even global.  If it stays local, most likely the CO will route the call to a Tandem office or equipment in the building and back out to a local Terminal to the end-user.  If it’s out of territory state/country, then the CO must pass the call to essentially a large lookup table in the PSTN until it reaches its destination.


What is the term Circuit Switching in POTS

If you have ever watched an old black and white movie when a person picked up a telephone and asked the operator to connect them to another location, well that is essentially how circuit switching started. ¬†The operator would ‚Äúplug‚ÄĚ the connection into the receiving slot on the board to connect the call. ¬†Imagine in our world today, the lack of privacy having to speak with a live operator to place a call for us. ¬†POTS lines expand across a network topology of Circuit Switching which dedicates a transmission path even if nothing is passing over the wire. ¬†This can be very tedious and resource-intensive. ¬†It‚Äôs also much slower compared to Packet Switching¬†which many organizations use today for their traditional data routing.


2 reasons why are POTS lines going away?

The 21st century has seen many advances in technology and the sunsetting of former solutions once thought impossible to change.  Faxing documents has not been around as long as the telephone however more virtual file sharing took over quickly.  POTS lines are sunsetting for these basic reasons

  1. Limited Reach:  POTS lines technically can connect anywhere in the globe, however, if you compare the tech such as VOIP it has surpassed POTS.  Additionally, as more building of new office structures or even healthcare agencies, new infrastructure is required including telephone lines.  With the FCC relief mentioned in this article, carriers are not obligated to install new lines into a new building.  Thus, enterprises are faced with the grim reality they must use something other than a traditional analog copper POTS line;  it simply will not be installed.
  2. VOIP is cheaper:¬† All VOIP lines run over an existing Internet connection and can offer unlimited local and long-distance calling for enterprises. ¬†This provides a fixed monthly cost which is exactly predictable and easy to manage.¬† If there is an issue on the VOIP network and your internet connection is working just fine, there most likely isn’t anything to troubleshoot on-site.¬† That is a huge advantage plus with remote workers, dial plans and terminating calls can occur anywhere in the world.


You might be asking should you immediately replace your copper analog lines?  The answer is no unless the carrier is moving your pricing to tariff rates or has officially given notice to turn down their copper product.

Would you like to receive a quick free assessment of your POTS lines and possible savings?  Contact Us and an Engineer can review your copper environment in 15 minutes.

Happy Dialing!