VoIP Resources VoIP Fundamentals Introduction to Business VoIP

VoIP Advantages and Disadvantages Versus the PSTN

by Margaret Joy

Landlines are familiar, and they've certainly stood the test of time. But how does the plain old telephone service (POTS) actually stack up next to VoIP?

Any utility has its pros and cons. It’s true for your phone service, whether you chose VoIP or a landline (aka the public switched telephone network, or PSTN). When choosing a phone service provider for your business, take a look at your specific needs. Someone else’s pro might be your con, so it’s worth comparing all of your options. Naturally, we’re biased toward VoIP (especially hosted VoIP!). That said, the advantages and disadvantages compared to the PSTN are fairly clear cut, so it’s up to you to decide which works best for you. 

Advantages of VoIP


VoIP is much cheaper than landline service. Copper wiring is expensive! And to have landlines in your office, you need to run wiring to every phone there. With VoIP, all you need is WiFi. Your desk phones may still have cords running out, but that’s likely Power over Ethernet (PoE) to supply a direct connection to your phone. 

After the hardware, VoIP is cost-effective because it runs on the Internet, so no need for stacked fees from telco companies just for supplying connection. Telco fees notoriously pile up. From adding a new line to hidden charges you wouldn’t see unless you combed through your bill, there are a hundred ways to lose money on PSTN phone bills. OnSIP hosted VoIP, on the other hand, offers flat fees

Landlines cost quite a bit in time as well. Setup and wiring is a hassle that no one wants to deal with. Setting up a VoIP system like OnSIP will cost you little more than an hour!


You can’t take wired phones with you wherever you go. When you leave the office, that phone is ringing into the void. Stuck at home? You’re unreachable. VoIP works a bit more like email. You can check email anywhere you’re logged in. VoIP calls go to your SIP address, kind of like an email address, so any device logged in will ring. You get to choose how to answer. This even works for a large office or warehouse, not just for on-the-go or remote employees. If you’re several floors away from your desk, you can answer a call on hold from any device with tools like call parking

OnSIP developed its own softphone apps for web, desktop, and mobile. Developing proprietary apps means OnSIP doesn’t have to rely on third-party vendors and can instead focus on delivering a consistently reliable service, no matter your device. This means you have every option for answering calls even if you’re away from your computer, your phone dies, or you need to run an errand.


One of the best advantages over the PSTN is VoIP’s versatility. Landlines are phone lines only. But modern communications includes so much more than just voice. We chat, talk, and have video conferences, often engaging in several channels at the same time. Instead of paying multiple vendors for voice, chat, and video tools, just use a reliable VoIP provider

Your traditional telco can offer expensive copper lines. VoIP providers like OnSIP can offer an entire platform of features. Because they combine multiple forms of communication in a single, streamlined interface, these platforms unify your communications—hence the term Unified Communications as a Service, or UCaaS. Besides the single interface, UCaaS platforms stand out because they are hosted, meaning the service is in the cloud, and end users use it without maintaining hardware, like servers. 

Disadvantages of VoIP

There’s one obvious answer here: Power. If you lose power or your WiFi cuts out, you’ve lost your VoIP service until it’s back. Landlines run independently of regular power lines. That’s why horror movie bad guys always cut the phone lines. (See: Michael Myers in every Halloween movie.) This is helpful during a blackout because you can still call emergency services. 

However, this only works for literal landlines—any portable phone with a handset still needs electricity to send the signal from the base to the device. Also, landlines run separate because the copper wiring feeds straight to the phone company. If the phone company loses power too, you’ll have landline service only as long as the backup battery system has juice. After that, you’re out of luck too. 

So Which One Do You Choose?

So there you have it: the pros and cons of phone service options. We have our opinions, but we also recognize that each business has different needs, priorities, and Internet connections. Someone in rural Americana where 2G is still the best connection would benefit from legacy landlines that crisscrossed the country decades ago. For the bootstrapped startup in the city, VoIP stands out. Whichever your choice, we are here to help guide you to your best phone system option.

Learn more about VoIP Fundamentals