Understanding SIP Trunking

Business phone technologies continue to evolve. Instead of relying on traditional phone systems, businesses today are upgrading to fully virtual phone environments, the most popular being session initiation protocol (SIP) trunking over VoIP (voice over internet protocol).

This useful technology offers you a customizable, scalable and cheap business phone solution. Learn what SIP trunk protocol is, how it can benefit your business and what to look for in a SIP trunk provider.

What Is SIP Trunking and How Does It Work?

SIP trunking is the process of sharing lines across devices in the workplace instead of procuring individual lines for individual devices. SIP trunking minimizes the number of telecom lines to your business while increasing the maximum data bandwidth.

SIP trunking can replace a traditional business phone line, and it can connect directly to the public switched telephone network (PSTN). This allows VoIP users to make calls to any phone on the PSTN without the need for telephone lines using a cloud-hosted PBX system.

SIP technology handles the traffic for voice phone calls no differently than it handles the transmission of any data. To the SIP system, video conferencing, phone calls, emails or sharing documents are all the same. They are all transferred as data packets. Since everything originates as a local call, there are no additional costs for long-distance calls or video streaming.

SIP Protocol: Replacing Phone Lines With the Internet

A protocol is a set of rules that tells devices how and when to send and receive data. The session initiation protocol was developed to enable communication over the internet. Internet telephony is where we see SIP employed the most.

With traditional phone lines, there were serious limitations with the type of data that can be transferred. That changed with SIP. With SIP, you can transfer more than one type of data. You can add media types like video, messages and text in addition to voice data. This makes SIP the go-to option for creating communication networks that can support video conferencing and other multimedia communication options.

A thing to note here is that SIP cannot provide any communication service of its own. It is a layer that acts between devices to facilitate communication over the internet.

Benefits of SIP Trunking

Traditional lines have served the business world in its growth. However, modern businesses have a different set of requirements. With SIP trunking and unified communications, businesses can now finally take advantage of digital communication.

If your company is plagued by high monthly phone bills, has numerous incoming phone lines, consistently racks up long-distance charges and is limited to legacy equipment and technology, SIP trunking may offer a better solution. You only pay for the number of lines you need rather than locking into a fixed number of lines or using only a portion of your bandwidth. You can purchase either unlimited SIP trunking or a pool of minutes subject to overage charges. This eliminates wasted resources.

Some of the most notable SIP benefits are:

Lower Operating Costs

SIP trunking brings in notable cost savings to businesses. Traditional phone services bill their customers varying costs based on the types of calls made and the distance. Moreover, multimedia messaging is costly, which hinders businesses from using this type of service. With SIP trunking, there are no hidden costs and the services are billed per user, which makes billing predictable.


Businesses are always on the lookout for scalable and sustainable services. SIP trunking rises to the challenge, as organizations can now share the lines of a network without any loss in bandwidth. This means individual lines per device are no longer necessary with the SIP trunking setup.

Multi-Device Support

Traditional phone lines were limited when it came to the devices they could support. SIP allows employees to connect to the office network from their own devices using VoIP apps. This enables devices to stay constantly connected to the network and even help employees work remotely.

A Single Network for All

With traditional communication lines, you need phone lines for voice communication and data lines for the internet. SIP gives you a more feasible alternative. Devices can share lines because SIP trunking allows the transmission of data and voice. In other words, your company doesn’t need additional phone lines for every additional employee. You can create an additional connection from an existing line without the added costs.

Cloud-Based Technology

SIP trunking uses the latest in data and communication standards and takes full advantage of cloud-based data processing. With cloud technology, businesses need not invest in costly on-premise hardware or worry about recurring maintenance costs. Cloud hosting unshackles businesses from the burden associated with on-premise systems.

Single Point of Management

Most SIP trunking services come with a dashboard from where you can manage sent and received business communications. This administrative portal helps you understand the data requirements of your business and how effectively resources are being used within the organization.

SIP Line vs. SIP Trunk: What’s the Difference?

In practice, there's not much of a difference. The two terms both refer to your VoIP connection, so there isn't a literal distinction between them. That said, there are real differences.

These differences are more pronounced when we talk about individual links, such as a SIP line between you and any other phone subscriber and a SIP trunking service connecting you to the public phone network, allowing you to make and receive phone calls.

These two terms also become useful when visualizing how much capacity a single VoIP subscriber needs to make concurrent phone calls. A call between two parties is carried by a line, and a trunk carries or represents multiple lines. So if you need capacity for 100 simultaneous calls, that's a SIP trunk that holds 100 lines.

Factors to Consider When Buying a SIP Trunk

When purchasing a SIP trunk for your business, consider the following factors:

Technical support: Round-the-clock support to ensure uninterrupted service

Security: The use of encryption, antivirus software and firewalls to protect your data

Equipment quality: The use of high-quality equipment to minimize breakdowns that can lead to costly downtime

Network design: Fast, reliable and secure networks designed to meet the specific needs of your business

Sufficient bandwidth: The ability to support a company's growth by building in the capacity to accommodate the number of employees and devices as projected by the business plan

Backup and redundancy: A well-designed backup plan and redundant connections to prevent costly downtime or loss of data in the event a network goes down for any reason

Service plans: Pricing and capabilities to meet the requirements and budget of your business

Combining SIP Trunking and UCaaS: A Complete Package for Businesses

UCaaS or unified communications as a service offers businesses a variety of cost-effective digital communication options over the internet. It can adapt to a company’s growing needs and comes with a host of impressive features.

SIP is an integral part of UCaaS. Together with technologies like VoIP, it provides businesses with unmatched call quality at very low latency. Integrating SIP to the UCaaS platform improves the capabilities of the SIP system in many ways. Many companies use SIP for its VoIP benefits and pretty much stop there.

However, the field of communication is evolving, and SIP wasn’t just developed to facilitate VoIP calls. It’s also used with a variety of multimedia communication options.

UCaaS is a mix of popular communication methods, giving businesses the freedom to choose what they want to use from it. UCaaS provides a pay-as-you-use model or a monthly subscription, which is more cost-effective than the unpredictable bills of traditional phone lines.

Combining UCaaS and SIP isn’t just a way to maximize the capabilities of modern digital communication methods, but a right step in what will be the future of enterprise-level communication.

How Can 8x8 Help?

8x8 offers cloud-based solutions that can handle your business phone needs as well as integrate your additional mobile devices. By providing unified communications across platforms and devices, your team can interact with each other and your customers on any device at any time in several different ways. Phone calls, meetings, conferencing, team messaging and contact center capabilities are all handled efficiently in a cloud-based network.

These unified communications tools use pre-built APIs to allow apps such as ZenDesk, Netsuite and Salesforce to integrate into your system for easy access or sharing. This way, you have a single data source across devices and systems for ease of analysis. 8x8 also provides security compliance certificates for FISMA, SOX and HIPAA.

Get Started With SIP Trunking Today

SIP trunk protocol has changed the way business phone systems work. A SIP phone makes communication across your organization more effective, helps you cut costs and adapts to your changing business needs.

Choosing the right technology is crucial to a growing business. Take the uncertainty out of the equation by choosing a SIP technology provider that can scale to meet your business' needs, whatever they may be at any given time. Call 1-866-879-8647 or fill out the form below to request a no-obligation quote from an 8x8 product specialist.

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