The Ultimate Guide to SIP Trunking: Everything You Need to Know

Data and Voice · Jun 6, 2023

SIP Trunking is a secure, reliable, flexible alternative to legacy cabling that opens new communications opportunities. Explore the benefits of SIP Trunking for businesses of every size.

There’s no doubt that Session Initiation Protocol (SIP) trunking is drastically changing how we do business. According to Transparency Market Research, the global SIP trunking services industry is anticipated to grow at a 14.1 percent rate until 2031, reaching almost USD $44 billion.

This next generation communications technology provides functionality, flexibility and feature enhancements that are not offered by legacy services like ISDN / PRI, and as older technologies are increasingly being phased out by carriers the cost savings offered by SIP are being embraced by enterprises around the world.

Wondering if SIP is right for your organization? Here’s what you should know when deciding if your company should embrace SIP trunking.


SIP trunking services are provided by carriers as a next gen replacement for traditional wire-based telephone lines, and one of the key differences is that SIP trunking is provided over existing data and internet connections.

Carriers offer SIP trunking as both a retail service that enterprises can purchase directly, and as a wholesale product that service providers can resell as part of a bundled package. This multi channel approach to markets ensures that customers can purchase SIP trunking services in a model that best suits their needs.

Because SIP trunking is delivered over internet connections, it is much easier for customers to “burst” their service at busy times in a way that is not possible with traditional fixed line telephony services.


Unlike traditional voice services which require a fixed and dedicated physical connection, SIP trunking uses data services to connect voice calls. The SIP trunk provider presents voice calls as a data stream via the internet, and they are packaged as virtual phone lines.

SIP trunking does require an enterprise phone system that is capable of receiving calls using the SIP protocol, but SIP calls are otherwise indistinguishable from their legacy counterparts. DIDs can be added or ported from a customer’s existing service to their SIP trunks.


Investing in a SIP trunking solution for your small or large business can simplify your communication system and make you technologically competitive. SIP trunking’s many benefits include the following:

Cost Savings

After its installation, SIP technology is significantly less than the cost of traditional voice technologies – as much as 65 percent, according to this report.

Since SIP trunking uses an internet connection, you can bypass many local phone company charges. No longer are you paying for extra lines you don’t need, and you can potentially reduce or avoid expensive charges for long-distance and international calls.

SIP allows for creativity of pricing models. Depending on the service provider, you may be offered metered and unmetered SIP trunk plans. Metered billing is a pay-as-you-go model that allows you to modify your service plan with your use of the service. Unmetered SIP trunking includes unlimited or bundled minutes per user or channel.

Unlike traditional phone lines, there’s no need for on site termination equipment and its associated costs. Instead, SIP trunk pricing generally consists of an install fee, a monthly rental charge for the broadband line, a price per channel (which can include a call allowance), and actual call charges.

Better Call Quality

With a SIP trunk-based phone system, you can experience better audio than analog versions. That’s because digital traffic is not susceptible to interference or corruption.

SIP trunks can also be used to support number failover. So, if the primary number can’t be reached, the call can go to a secondary number – even if it’s at a different location. This isn’t possible with traditional telephony services, which phone failures, bad weather, or damaged telephone lines can impact.

And in the event of a data connectivity problem, SIP trunking offers a failsafe for your employees’ devices. So basically, no matter what’s happening outside, your business communications can still run smoothly.


With a SIP trunk provider, it’s easy to scale your phone system up as your business requirements change. Since SIP trunks aren’t tied to a local exchange, you can set your business up with a local number regardless of location. In most situations, getting an additional line or a toll-free number can be accomplished instantly during one quick phone call to your provider. You can also add video, multimedia messages, and other kinds of messaging.

The same goes for when you no longer need as many existing phone lines. After letting your SIP trunk provider know of the change, you could start seeing a reduction in phone system costs right away.

Integration with Cloud-Based Applications

Unified-Communications-as-a-Service (UCaaS) and other cloud-based applications integrate better with SIP trunking. You can receive real-time access to analytics and data insights, including call-quality metrics and call screening.

You can also gather business intelligence and receive details about employee communications with customers. Use this invaluable information to improve employee performance and help avoid missed or dropped customer calls in the future.

Increased Security


Call Volume and Coverage

You should know how many simultaneous calls your infrastructure will need to support to determine the appropriate number of channels you’ll require in your SIP trunk. Each channel can handle one incoming and one outgoing call simultaneously. A good quality SIP service may also support bursting, allowing you to temporarily use more channels than you have contracted for, in order to ensure that calls are not rejected at unexpectedly busy times.

Reliability and Voice Quality

To optimize Quality of Service (QoS) and bandwidth, you’ll want a provider that understands modern digital networks and how to ensure that voice traffic is routed with the right level of priority.

The provider should also have connections with tier-1 carriers to route calls to other networks without imposing extra charges.

Flexibility, Simplicity, and Scalability

You’re investing in SIP trunking to simplify your communication landscape. Choose a provider that makes installation, management, and upkeep easy.

Once the service is installed, you may need the ability to scale your business. Certain service providers offer flexible service contracts and the ability to change phone numbers, add IP access control lists, and more.

Security and Privacy

For an additional layer of security, your SIP provider should follow strict security and privacy best practices. If your business operates in an industry with data privacy regulations, consider using a managed provider that encrypts SIP traffic using SRTP and TLS.


SIP trunking pricing options can be per channel, per minute, or as part of a bigger service fee that includes telephony infrastructure. Wholesale SIP trunking rates are also available to resale partners.

Each SIP trunk provider will have its own rates and pricing structures.


Because of a SIP’s ability to transfer various types of media (not just voice apps), security needs to be a priority for a SIP provider.

Each SIP provider will have unique security protocols for ensuring your SIP trunking is as secure as possible. One of the easiest ways to do this is by using a virtual private network (VPN) – a more secure and reliable option than public Internet.

You’ll also want to prevent malware intrusion by configuring your endpoint devices to require SIP authentication – namely, demanding a valid Uniform Resource Identifier (URI), a username that can be authenticated, and a secure password.

Any present intrusion detection and prevention systems on your network must also become SIP-aware.


The operational costs of SIP are significantly less than analog telephony services, varying depending on your business and its needs. The upfront investment is relatively low, and the technology presents significant savings on monthly costs and overhead expenses.

According to several Nemertes Research studies, participants reported average telecom cost reductions ranging from 20-60 percent after using SIP trunking. In one example, the implementation reduced a business’s audio conference costs by 90 percent.

With SIP trunking, you no longer have to pay for multiple unused company phone lines – instead, you only pay for what you need. And since your business is usually charged on a per-channel basis, there’s more predictability in billing costs.

SIP trunking is especially appealing for global businesses. Because the Internet is used for calls rather than intricate architecture and hardware, the expense of overseas calls is dramatically reduced. This Gartner analysis showed that SIP trunking reduced per-minute rates by an average of 25 percent.

Additional ROI is provided through insights from SIP’s cloud-based information. Real-time access to analytics and data insights can drive marketing, customer service, and sales improvements.


SIP trunking systems track everything about each call that’s made, providing you with analytics about your business’s communication patterns and trends.

The metadata gathered includes the source, destination, and date/time of the call, as well as call duration, country/region of the called number, billing rate applied to the call, and the cost of the call. Known as a call data record (CDR), this digital file of information on each call made is usually provided in a flat text, CSV, or another file format that can handle a large number of records.

Use your valuable CDRs to track call usage, monitor individual and team performance, manage customer complaints, and even detect fraud. Improve your sales and customer service experience using the data gathered on caller preferences, behaviour, and pain points.

You can create more effective marketing campaigns by identifying patterns and anomalies in your network. An added bonus? Identifying peak usage times and how many lines you currently use can lead to better budgeting.


By offering attractive reductions in telephony costs and greater flexibility, it’s no surprise that 70 percent of North American businesses have adopted SIP trunking. As more enterprises continue to transition away from their analog phone systems, the future of SIP trunking will continue to get brighter.

For one, the SIP services market will become closely integrated with UcaaS – a partnership that will bring tremendous growth opportunities in performance. Better codecs paired with 5G and edge computing will deliver faster, more reliable voice and video communications. There will also be enhanced security measures to offer protection against the latest cybersecurity threats.

Continual service innovation will be a priority by forward-looking SIP providers, who will work to ensure the associated bandwidth and network requirements are always met. Providers will launch new cloud-based SIP trunk services that promise to link and integrate various business environments while optimizing user productivity.


TELUS is ready to support your business operations with our next-generation SIP trunking solutions. Our SIP trunking covers the most rate centres of all carriers for new number requests with 95% of the population of Canada included in the TELUS footprint, helping thousands of other business owners achieve a more flexible, scalable working environment.

From startups to large enterprises, our SIP trunking services can be easily integrated into your communications strategy. Our robust, reliable network features redundant connections and advanced failover capabilities to ensure consistent business continuity.

TELUS’s SIP trunk pricing is competitive and our end-to-end solution comes with 24/7 support, ensuring you always have assistance.

We view security seriously as a SIP trunk provider for small and large businesses. That’s why we integrate advanced security measures, including encryption, to keep your business safe and to ensure compliance with industry regulations.

Get in touch with us to learn more about our SIP technology today, a dedicated TELUS advisor is available to help plan for your business needs.

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