This article is part of a larger series on VoIP.
Session Initiation Protocol (SIP) trunking is the method of sending and receiving communications over the internet through private branch exchange (PBX) equipment. It replaces traditional phone lines by upgrading your PBX to an internet-based phone network. Through this technology, your on-premise phone system benefits from unified communications services, such as video conferencing and instant messaging.
Keep reading to learn what is SIP trunking, how it works, and how it will optimize your business communications.
Looking for a SIP trunking provider? If you’re planning to switch to SIP trunking, try Twilio’s Elastic SIP Trunking service to keep you in control of phone connectivity and pricing plans. Get extra savings with pay-as-you-go pricing and access on-demand cloud features, such as voice insights and call control.
How SIP Trunking Works
SIP is a protocol that initiates and terminates cloud-based communications, such as voice calls, video chats, and instant messaging. It is used to support voice-over-internet-protocol (VoIP) to send and receive calls over the internet. Below is a simplified summary of how SIP trunking works:
- You use the office phone to make a call, which goes through the PBX phone system.
- Once the phone system identifies the destination of your call, it will deliver the call to your internet telephony service provider (ITSP).
- Next, the ITSP will use SIP trunking to connect the SIP-based PBX to the public switched telephone network (PSTN).
- The PSTN routes the call around and delivers the call to the ITSP of your recipient.
SIP trunks use a packet-switched network to break down voice calls into digital packets and direct them over a network to their destination. This enables business telephone systems to conduct real-time communications over the internet, such as video conferencing and instant messaging.
Top Benefits of Switching to SIP Trunking
SIP trunking transforms your business communications by upgrading your PBX to a cloud-based phone system. From bigger cost savings to unified communications, SIP trunking delivers an optimized calling experience for its users. Here are other potential benefits of SIP trunking:
1. Reduced Overhead Costs
One of the primary benefits of SIP trunking is it eliminates the need for traditional telephone lines, which requires users to buy circuits by the bundle to make simultaneous calls. SIP trunking providers use a virtual phone line bundle that relies on internet connectivity to deliver voice services. This leads to significant cost savings, which is ideal for businesses requiring multiple telephone lines to handle large calls.
Since SIP trunking uses digital lines, it offers more control over your network infrastructure. This reduces the costs and requirements for installation, in-house equipment, and maintenance of a traditional phone system.
Another benefit is the lower call charges for international and long-distance calls. SIP trunking providers offer simplified pricing packages based on usage, features, and add-ons.
2. Better Flexibility When Adding New Phone Lines
SIP trunking is easily scalable, depending on usage. It makes adding channels and coping with increasing call volumes possible—perfect for fast-growing businesses. SIP trunking allows users to choose the right number of channels they need instead of paying for lines they don’t use. Also, no need to worry about physical installations since most providers offer unlimited capacity.
SIP numbers are portable and have no location-based restrictions, allowing international companies to create a local number in other locations without a physical address. Plus, SIP trunking enables you to keep your existing phone number even if you’re changing offices.
3. Greater Reliability During Bad Weather or Network Issues
Whether it’s bad weather, equipment failure, or network issues, SIP trunking is more reliable than traditional phone systems. In case of failure, SIP trunking allows users to keep using their phones by routing calls to other devices or lines. The right SIP trunking provider should provide a disaster preparedness plan for troubleshooting.
4. Access to Enhanced Communications Services
SIP trunking boasts of its multichannel functionality by offering unified communications services, such as video conferencing, instant messaging, and application integration. SIP trunk providers have the expertise to give you the right services quickly and easily.
If you’re ready to scale up your business phone system with SIP trunking, learn how to set up a VoIP system to access enhanced communications services like team messaging and video conferencing.
Potential Drawbacks of SIP Trunking
SIP trunking involves a few issues that may likely affect the quality and delivery of phone calls. However, most of the problems stem from misconfiguration instead of the technology itself. Here are the potential drawbacks to consider before investing in SIP trunking:
1. Requires a Costly Upfront Investment
SIP trunking is resource-intensive unless you have an existing PBX infrastructure. Switching to SIP trunks demands a robust network infrastructure, SIP-compatible PBX, and VoIP-compatible phones. These all require a large upfront investment.
A single PBX box costs over $1,000, and you have to purchase a plan from an SIP trunking provider to access its software for your phone system. Also, you may need additional cables and maintenance for on-premise setups and outsource support if you don’t have an internal IT team.
2. Compatibility Issues With SIP Trunking Providers
Many first-time SIP users face compatibility issues when choosing a SIP trunking provider for their existing PBX. It also happens in non-PBX devices, such as fax machines previously connected to PSTN lines. This puts significant pressure on businesses to determine whether their PBX is compatible with the selected provider.
3. Good Bandwidth Is a Must
Businesses with poor internet won’t get enough bandwidth to handle VoIP calls or access VoIP dedicated server hosting. If you have a single data connection, your internet connectivity should support your phone system, including other processes that require data. If not, your existing call volume will affect bandwidth performance.
Factors to Consider When Choosing the Right SIP Trunk Provider
A SIP trunking provider helps businesses use their existing PBX to transition into an internet-enabled telephone network. The right one should provide your business with feature-rich plans that fit your budget and communication needs. Here are the factors to consider when choosing an SIP trunking provider:
SIP trunk pricing varies across providers. Most of them charge on a per-user or monthly rate with the ability to upgrade the number of channels at any time. Pricing may include cost per minute or per port, setup costs, call tariffs, number porting, maintenance fees, and bundled features. Evaluate bundle offers carefully, making sure that they fit your usage and preferred services.
A good SIP trunk provider has a clear data policy and secure network, protecting your data against cyberattacks and hacking methods. Find out the security measures they put in place and whether they have an anti-fraud system.
A reliable SIP trunk provider should help you address any network-related issues that may arise. Ideally, you need a provider that offers end-to-end service. They should define requirements, oversee configuration, and provide alternatives if something goes wrong.
There’s a chance the SIP solution used by a particular provider might not be compatible with your existing PBX. The right SIP trunking provider performs regular interoperability testing and informs you whether your hardware is compatible with their service. Top providers are capable of configuring their service to work with any type of PBX.
A SIP trunking provider should keep your business running despite an emergency, disaster, or peak hours. They should have a disaster recovery plan in place to help you cope with any situation, with access to business-grade service for your phone system.
Top SIP Trunking Providers for Small Businesses
There are plenty of options to choose from when looking for a SIP trunking provider. However, each provider differs based on features, scalability, and pricing plans. To narrow down your choice, we’ve already picked the best options for you.
Here are the best SIP trunking providers for a seamless transition of your phone system:
Vonage is one of the leading unified communications as a service (UCaaS) platforms. Its SIP trunking services enable fast-growing businesses to link their PBX system to the cloud in minutes and scale up and down as needed.
Users get valuable features, such as automatic location-based routing (a call management feature that routes calls through the closest gateway to reduce latency and enhance call quality). Its pricing plans are an excellent option for businesses looking for a pay-per-use SIP trunking provider that charges per second. Pricing for making calls starts at $0.0143 per minute, while receiving calls is at $0.0051 per minute.
Get more information on how Vonage works by reading our comprehensive Vonage review.
Nextiva is the better option for fast-paced businesses looking for a hassle-free SIP trunking setup without coding. Ready-to-use SIP trunks allow users to bring their PBX to the cloud with guided support to ensure successful porting. Features include fraud mitigation, detailed call records, and online management.
Nextiva offers flexible and simple pricing options to meet your needs. The metered plan is $14.95 per month plus $0.0008 per minute, while the unmetered plan is $24.95 per month with unlimited calls nationwide.
If you want to know more about Nextiva and its services, head to our Nextiva review.
Twilio offers Elastic SIP Trunking service, enabling businesses to take control of their connectivity and enhance communications agility. This is perfect for enterprises looking for a flexible SIP trunking system with the ability to scale up and down.
Twilio offers pay-as-you-go pricing on all plans—no contracts or channel limits included.
The price to make and receive calls varies based on the destination. For local numbers, the price starts at $0.0050 per minute. Supporting features include Voice Insights, a powerful tool that tracks and troubleshoots call performance issues.
Frequently Asked Questions (FAQs)
What is the difference between VoIP & SIP?
VoIP, which stands for voice-over-internet-protocol, refers to any phone call made over the internet. SIP, which stands for Session Initiation Protocol, initiates and terminates communication sessions in VoIP platforms, including messaging, voice, and video.
Does switching to SIP trunking require a huge investment?
The initial setup cost for SIP trunking depends on the existing PBX hardware you already have. It’s up to you whether you want to retire your old equipment and purchase new. Expect to pay between $500 and $2,000 for this equipment investment. To get more savings, compare the setup costs with available providers.
What are the requirements to set up SIP trunking?
There are three requirements for SIP trunking implementation: internet connection with adequate bandwidth, VoIP phone, and SIP-compatible PBX. If you have an outdated PBX system, you will need to buy a gateway to connect it to SIP trunks. Otherwise, newer systems don’t require additional hardware.
SIP trunking revolutionizes business phone systems without requiring a large upfront investment. SIP trunks’ internet-based solutions make them more reliable, flexible, affordable, and scalable compared to traditional telephone lines. This makes SIP trunking a useful transitional technology for fast-growing companies that want to control their telecom spending.
If you’re looking for the best SIP trunking provider, try Twilio’s Elastic SIP Trunking to access on-demand cloud features and pay-as-you-go pricing plans. It will help you utilize SIP trunking for better global connectivity.