SIP Trunking—a Powerhouse for Business Communications

What Is SIP Trunking?

Session Initiation Protocol (SIP) is used in multimedia (voice and data) communications over the public internet or other private IP networks. It handles setting up, managing, and terminating sessions. SIP trunking is a communication method that operates using your internet connection rather than a traditional phone line. It’s a popular business communication system because it’s scalable, affordable, and flexible.

SIP as a technology handles several telephony and communication functions:

  • Availability. SIP allows users to show whether they’re available or not.
  • Devices or features. SIP can tell what functionalities (voice, video, etc.) a user’s device can support and set up the call accordingly.
  • Management. SIP allows users to connect, disconnect, transfer, or modify communications.

The term “trunk” has been historically used for a physical circuit. SIP trunks are virtual rather than physical, but the concept still applies. A SIP trunk has multiple SIP lines—and these lines are more flexible than traditional circuits. You can purchase as many SIP lines and trunks as your company needs instead of paying for a set number of traditional lines you don’t need. 

SIP Trunking vs VoIP

Voice Over Internet Protocol (VoIP) is an umbrella term that refers to technologies used to make voice phone calls via the internet. SIP falls under the VoIP umbrella because it’s a protocol used to set up, manage, and terminate sessions, but SIP trunking allows you to make multimedia calls instead of limiting you to voice only.

While VoIP is a broad term, it’s most known as a delivery method for communication. It’s sometimes referred to as an internet telephony service or a cloud-based phone system. This technology is becoming an increasingly popular form of both business and consumer communications. If you’ve used Skype, you’ve used a VoIP solution.

The main difference between VoIP service and SIP trunking are the types of media used. VoIP allows users to make voice calls, while SIP phone systems also have video and data functionalities. SIP as a communication method is more intuitive than VoIP—it can detect device capabilities and adjust accordingly. This might mean that a conference call could include a few people using video and others using voice only.

However, the multimedia capabilities do make SIP more complicated than VoIP. Consider your company’s IT capabilities, support, and budget if you’re considering either option. 


Is SIP Part of Unified Communications?

Unified communications (UC) allows you, your employees, and your customers to interact using a variety of communication technologies. It’s not a single product, protocol, or technology—it’s an umbrella term for several technologies that support multimedia communications. These could include email, chat, VoIP calls, video conferencing, and more. UC helps your business create a multifaceted approach to communications, which can prevent slowdowns.

SIP falls under unified communications. Adopting SIP phone service (or VoIP) is a great way to ease your company into UC. You’ll need some sort of IP telephony service in order to implement a UC platform.

Unified communications provide both real-time communications (calls and instant messaging) and other types of communication that aren’t “real-time” (email and social media).

UC typically allows the user to switch communication methods at will. For example, you could listen to a voicemail using your computer or switch a desk call to your smartphone before heading to a meeting. This flexibility means unified communications can improve productivity and customer service.

SIP Trunking vs PRI

SIP trunking and Primary Rate Interface (PRI) are two types of phone connections. SIP allows you to communicate via the internet. PRI is a standard used in the Integrated Services Digital Network (ISDN), allowing you to make calls using a physical location. SIP trunking can be used by most businesses, while PRI is designed for larger companies.

There are several reasons why PRI would work for your business:

  • You have existing phone equipment that isn’t compatible with VoIP or SIP.
  • You need high-quality calls and service.
  • You have more resources (IT and money) to devote.
  • You are part of a large enterprise.

There are also many reasons for your company to choose SIP:

  • You have a smaller budget.
  • You need new phone equipment.
  • You need a system that scales easily.
  • You don’t want to use traditional phone lines.

PRI is similar to what you’d expect from a traditional phone service provider. It requires physical lines between two locations. The need for a physical connection means it’s more expensive to set up, and a PRI system could also be complicated to expand or scale. SIP trunking might be the better option if you’re planning on growing or relocating your team. 


SIP Phones Compare vs PBX Phones?

Private Branch Exchange (PBX) is a phone network that can make calls using VoIP technologies or traditional phone lines. It can be hosted at your location or used as a cloud-based phone depending on the type you choose—traditional PBX or IP PBX (either on-site or hosted).

With traditional PBX, your business would house the equipment at a physical location. The primary reason to choose this type of system is that you only have to lease the number of lines needed for concurrent calls.

IP PBX has more modern capabilities compared to its traditional counterpart. IP PBX can be hosted or on-premise. This gives you the option to make and receive calls via a normal phone line or via the internet using SIP trunking capabilities. On-premise involves buying equipment like a traditional PBX system, which makes hosted easier to scale. Hosted can be more affordable to set up, while on-premise may have a more affordable monthly payment.

Hosted PBX is considered a VoIP and unified communications solution. It relies on your internet connection to make phone calls, and all equipment and servers are housed at your provider’s physical location. That means you can simply plug your phones into a router and get started. Hosted PBX is flexible and scalable—all you need to do is buy more phones.

Is SIP a Good Choice for Your Business?

SIP trunking is one of the most flexible communication methods. Its flexibility makes it a very popular choice for businesses.

SIP may be right for your business if you answer yes to any of these questions:

  • Is your company already looking to switch phone systems?
  • Do you plan on growing or relocating within the next few years?
  • Are you and your workers making frequent long-distance calls?
  • Have you decided you don’t want to purchase and maintain equipment?
  • Do you want or need multimedia options like video?
  • Are your employees taking business trips or working remotely often?
  • Do you have a small IT budget or staff?
  • Are you looking for cost savings to help boost your bottom line?

Perhaps the single most important part of integrating SIP trunking is having a reliable high-speed internet connection. Ensure you have enough bandwidth to handle the voice calls, video, and data you plan on sending and receiving in addition to the activities you already use your internet for. Additionally, find SIP trunking service providers that understand your business needs and work with you.

SIP, other VoIP technologies, and unified communications aren’t going away anytime soon. In fact, they’re growing rapidly. Now is a great time to jump on the bandwagon if you’re just starting out or looking to upgrade your current phone system.