Excellent communication is key to the success of a company. Sometimes, a company’s success depends on how well your people can communicate. This kind of communication doesn’t only involve your team, but it also includes your clients, partners, and prospects. What is SIP calling? We’re going to answer this question in a bit. 

With Session Initiation Protocol (SIP), your existing PBX phone system’s movement to the cloud will be easier to accomplish. Plus, this system enables Voice over Internet Protocol (VoIP)

SIP calling plays a crucial role when you’re dealing with overly expensive calls within and beyond your calling accounts. This article aims to discuss what it is and how it works. Keep on scrolling to learn more about SIP calling. 

What is SIP Calling?

SIP calling is also known as Session Initiation Protocol calling. Generally, it’s the process of transmitting voice calls over a SIP channel. Sometimes, SIP and VoIP are interchanged, but SIP uses VoIP to transfer analog call traffic over the Internet, making things flow more smoothly. SIP is a protocol used in VoIP communications to allow users to make voice or video calls.

A traditional phone system consists of PBX and PRI (Primary Rate Interface) lines. The PBX includes call management features like voicemail. Meanwhile, the PRI lines are responsible for connecting calls to the PSTN (Public Switched Telephone Network). 

Once you have SIP, you’ll be able to bypass PRI lines and directly connect to the PSTN via the Internet. Overall, SIP calling makes communication easier. SIP calling allows people to communicate effectively using computers and mobile devices, depending on which they prefer. Its internal and external functions for communication are beyond impressive.

How Does a SIP Call Work?

SIP calling works by removing the need for PRI lines. As mentioned above, SIP calling enables you to connect directly to the PSTN. 

It works by sending messages from one SIP address to another, serving as an over-the-internet exchange of information.

How does it accomplish this?

The phone line that uses the SIP protocol is called a SIP trunk. This phone line should be installed virtually over your internet connection. This part is where your VoIP plays a crucial role. Once the SIP trunk has been installed, it will pave the way for the internet connection to connect your PBX directly to the PSTN, bypassing the PRI lines. 

Once everything falls into place, this SIP trunk now allows you to use call management features like voicemail, call forwarding, auto attendants, and so much more. The use of SIP calling removes your need for a physical connection to a phone company. 

Benefits of SIP Calling

SIP calls have good reasons to future-proof your company’s communication system. Most of these reasons stem from the benefits you can obtain from this protocol for your businesses. 

These benefits include the following:

benefits of sip calling infographic

1. Affordable 

If you’re struggling with expensive calls and other communication forms, switching to SIP might be the best way for you to earn massive savings. Firstly, this protocol allows business owners to be more cost-efficient by eliminating installation, hardware purchases, and maintenance costs. 

Secondly, SIP calling also eliminates multiple networks and multiple subscription fees. If you compare all the setup costs associated with the traditional phone system, using SIP calling will benefit you more financially. 

2. Easy to Maintain

SIP phone systems don’t require or demand too much maintenance. This one is a lot easier to maintain. In times of issues or technical difficulties, there are several tools available to resolve them immediately. 

Also, SIP trunking providers can quickly reroute services, making them more user-friendly as well. 

3. Easy Scalability 

Once you switch to SIP phone systems, the need to buy channels happens only one at a time. There’s no need to add more telephone lines or pay for more installation costs to grow your business. SIP calling is scalable, and everything from phone calls to video calls happens over the Internet. It also makes it easier for your team to access new carrier services.

4. Flexible

Generally, SIP calling helps you create a unified virtual space. Users will no longer need to buy more channels or consistently switch between different communication channels because, with SIP calling, you’ll be able to synchronize all of them.

For instance, if you’re handling a team of 20 who are remotely working from different parts of the world, each one of them can be reachable through their smartphones. SIP calling makes communication a lot more efficient and flexible. 

It also maximizes remote employee productivity since it eliminates common issues in communication.

5. High-Quality Calls

The traditional phone system can fail you for many reasons. Its connectivity can be affected by different external factors such as power outages, bad weather, calamities, and internal factors such as system failures.

Fortunately, SIP calling allows users to enjoy high-quality calls without interruptions. How? Because this system can reroute your calls to other locations, depending on which favors your lines the most.

6. Efficient

A SIP call bypasses the PRI lines, therefore making a direct connection to the PSTN. This ability of SIP calling shortens the process needed for an efficient flow of communication to take place. You’ll not only save resources, but you’ll save time too.

7. User-Friendly

SIP calling is never difficult to figure out. It’s even easier to install than the traditional system we’re all used to. If you have a group of people on your team, it’s best to train them using only a single system to simplify all the processes involved. Once they learn the concept of SIP calls, all of your communication needs will be consolidated into one device. 

Who Should Use SIP Calling?

Both large and small businesses can benefit from switching to a SIP call. More importantly, companies with an existing PBX system can take this opportunity to take their PBX system to the cloud.

However, it remains inevitable for large businesses to be hesitant in switching to the SIP call. The challenge stems from the number of employees they have and the inevitability of any interruption or service disruption once they suddenly change their system.  

If you’re interested in switching to SIP call, here’s a list of the reasons why such a move is highly suggested:

  • SIP calling provides free internal calling.
  • SIP calling lets users enjoy time-management tools.
  • SIP calling makes international calls more affordable.
  • SIP calling allows users to combine technologies and platforms a lot easier. 
  • SIP calling functions anywhere with the Internet. 
  • SIP calling allows users to integrate all communication channels.
  • SIP calling makes collaboration and connection easier to attain.

Whether you own a large or small start-up business, moving your communications to the cloud will let you save much money in the long run. A SIP call is an investment, and it will always pay off in the end. 

Can I Make SIP Calls on iPhone and Android? 

SIP calls can be made both on iPhones and Android phones. However, there will be a particular configuration needed to activate this feature. Smartphone users need to use a SIP dialing app to make this possible.

For iPhone users, you may need a third-party application to make SIP calls. Why? Apple is equipped with developer tools to integrate the phone’s calling capabilities. 

To enable SIP calls on your iPhone, download the ULTATEL App.

There are built-in settings for Android users where you need to register your device with a SIP provider. Google provides these settings. To make the experience even more enjoyable, Google also offers more calling interfaces that users can use.

To enable SIP calls on your Android phone, download the VoIP app from your VoIP provider like ULTATEL. If you don’t have the app, you need to configure your phone settings.

What’s the Difference Between SIP and VoIP?

SIP and VoIP are two different things. SIP is a control protocol used for VoIP call setup, and tear down. SIP helps you take your communication system to a higher level. 

Users can use SIP to modify and terminate multimedia sessions like VoIP calls. This system sends packets that include data, voice, or video. SIP can also perform independently without the presence of a computer.

Meanwhile, VoIP mainly uses the internet connection to make and receive calls. It utilizes a connection of technologies that can send only voice content over the internet. VoIP phones are dependent on computers, so you’ll need to have them connected. 

In simpler terms, VoIP is used to describe any internet-based phone service, while SIP is a protocol used for most VoIP deployments. VoIP isn’t a protocol itself. VoIP is an umbrella term for all the technologies involved in transporting voice and video information using IPs.


A SIP call is meant for companies who want to make full use of their installed PBX and not only communicate over IP within the company – ULTATEL can help you transition from a 100% on-premise phone system to a hybrid solution that uses SIP trunks to connect to the PSTN. Ultimately, this solution can help you quickly save, move and make your next move to the cloud much easier in the near future. 

Choosing to keep the air of old school and traditionalism will be a costly decision in the long run. SIP calling is an excellent option to consider, especially when you’re tired of paying expensive calls and other excess costs involving communication flow. 

A SIP internet call and SIP Voice over IP are two significant innovations in this modern technology. ULTATEL’s SIP calling will optimize network capacity across all company’s locations and on any device.