What is SIP Trunking? Session Initiation Protocol (SIP) – or “SIP Trunking”, as it is commonly known – is a phone system feature that is frequently accompanied with VoIP phone systems to providing optimal call quality and consistency.
VoIP phone setups are far cheaper and more flexible than traditional lines, and SIP trunking provides a dedicated connection to the Public Switched Telephone Network (PSTN) to ensure internet-based calls can be made just as reliably.
“Trunking” is a term that was used in the early days of the telephone service. A trunk was a way in which large numbers of users could share a communications path. SIP Trunking today is just one of the protocols offered by VoIP providers, as VoIP is fast becoming the global business standard.
This guide will examine the best SIP Trunking providers to choose for your business, as well as a number of areas related to Session Initiation Protocol (SIP). This includes more detail on exactly what SIP is, how it works, and a SIP price comparison so you can ensure you’re getting the best solutions for your budget.
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Top 10 Best SIP Provider Reviews
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|Provider||Price From||Our Rating||Highlight|
|$24.95/mo||Automatic call rerouting|
|$24.99/mo||7,000 rate centers in US|
|$0.0055/min||E9-1-1 across the US|
|On Request||No contract necessary|
|$19.97/mo||Offers call analytics|
|$19.95/mo||Keep existing phones|
Nextiva offers businesses a range of SIP trunking options which are designed to save money on business communications. By routing through Nextiva's SIP trunk, businesses can benefit from unlimited local and long distance calling features, without changing their existing PBX equipment.
With this service, any traditional phone system can be quickly converted into a dedicated IP based system to manage communications, and calls can be auto-rerouted to alternate numbers if needed. The company offers an unlimited contract starting at $24.95 per month, which includes everything you need to set up and run a fully functioning communications system. Nextiva also offers a metered plan that starts from a flat $14.95, and adds $0.008 per minute used. We'd recommend the unlimited plan, as the minutes can add up quickly. Either one includes a free trial.
- 100,000 customers
- Unlimited calling in US and Canada
- Simple set up
- Mobile app
- HD voice
- Auto attendant
- Call recording
8×8’s SIP trunk uses a VoIP dial tone solution that can be scaled to the needs of businesses large and small. The service provides free calling between 8×8-enabled systems, and emphasizes its pay-as-you-grow scalability. It also offers a variety of service plans, all based on 6-second billing increments.
As a leading name in digital communications and with 7,000 rate centers nation-wide, 8×8’s SIP trunking is reputable, and best suited for companies who may experience fluctuations in growth.
- 40,000 customers
- Options of metered, unlimited or global extensions
- Integration features
- Web conferencing
- Call recording
- Internet fax
- Instant messaging
- Online call management
Hosted through PBX, Vonage is a business VoIP provider offering both affordable and reliable solutions for businesses. Ideal for companies that employ 50 staff or fewer, the company is a market leader in VoIP solutions for all types of business. Vonage owns its own software – an advantage it holds over some of the other providers – which means it can offer a higher level of quality with its SIP services.
Pricing is charged on a monthly basis, but customers aren’t locked in to long term contracts – something which always appeals to the budget conscious business. This SIP provider offers a number of advanced features, with an easy to navigate interface, first class customer support, and dedicated customer service when you need it.
- 2.4 million worldwide customers
- Unlimited calls in the U.S. and Canada
- Customizable conference groups
- Voicemail transcription
- Call recording
Bandwidth offers a SIP trunking service that covers domestic and international long distance calls. Its also comes with white page listing included, lets users view caller ID and locations on inbound calls, and comes with both types of pricing plans. The service charges a metered plan that costs $0.0055 per minute for inbound calls and $0.01 per minute for outbound, plus a flat $0.35 per phone line per month. Custom enterprise prices are available with a consultation.
Bandwidth also offers enhanced 9-1-1 support (E9-1-1). This automatically identifies the location of anyone calling 9-1-1, routing the call to the nearest local Public Safety Answering Point and relaying location to the responder to ensure the fastest emergency response. Bandwidth is one of just a few providers to offer E9-1-1 coverage across the entire US.
- Toll-free support
- Inbound caller ID/Location
- Multiple pricing models
- White page listing
- Domestic and international calls
- Enhanced 911 support
Twilio offers quick access across the globe, while providing the prefix coverage a business needs to retain its recognizable local area code. An additional benefit offered by this SIP trunking service is the reliability of an effectively redundant, carrier grade VoIP network of Tier 1 carriers across over 100 countries. Twilio charges $0.007 per minute for toll-free numbers in the US, and between $0.007 and $0.25 per minute for extended zones, depending on the zone.
Twilio offers a stand-out customer support team, and includes Twilio Voice Insights tools with its service. These tools allow businesses to better parse data on their call performance by drawing out insights from details like packet loss, jitter, or PDD.
SIP.US puts the user in control of its SIP trunk services for IP PBX systems and analog-digital telephone adapters. Rather than locking customers in to a corresponding bandwidth plan, SIP.US lets you use your preferred bandwidth supplier.
Additionally, the company provides an easy-to-use, self-managed interface where you can add or change service, as well as review call data records. For a trunk with unlimited capacity, SIP.US charges $24.95 per channel (i.e., per line). Its phone number pricing amounts to $1.00 per month in the continental US, with international numbers starting at $5.00 per number per month.
SIP.US is easy to manage and offers excellent customer service.
- Reliable Support
- Fraud Protection
- Simple Pricing Structures
- Self managed interface
- Freedom to choose bandwidth provider
- Pre-paid, no contract
Voxbone offers a fully redundant, Tier 1 network of national operators covering over 60 countries, and delivers great uptime to its customers. Voxbone offers three main plans: Starter costs $500/month, Growth is $2,500/month, and Scale Up is $5,000/month. While these prices seem much higher than most of the ranges listed on this page, they offer unlimited minutes within the channel limit, even when calls are concurrent – saving businesses from buying multiple trunks. Voxbone is best for businesses with call capacity needs that can vary, but who still want a fairly predictable overall monthly cost.
Setup costs are an additional charge, and the service doesn't prorate its plans – so you may want to wait until the beginning of the month to upgrade. However, Voxbone's range and reliability are hard to beat, and its 24/7 support team has a track record of prompt responses.
- Reliable coverage
- Easy number porting
- 24/7 support
- Metered or capacity pricing
- Online training and webinars
- Online support
Net2Phone’s SIP trunking service allows businesses to take advantage of international DIDs (phone numbers) from over 50 countries.
Meanwhile, it supports unlimited concurrent calls, and offers a no-strings-attached pricing plan. The company offers free use of channels and no monthly contracts.
Net2Phone’s SIP trunking works well for businesses that have a heavy international call volume, and require the freedom of scalability.
- Scalable from 25 users to over 101
- Superb reporting package
- Integrates with Microsoft Office, Google and others
- File sharing
- Voicemail to text
- Call recording
Alliance Phones' most popular plan is its unlimited monthly model, which charges $19.97 per month and includes unlimited minutes across the US and Canada. The service also offers a metered plan that charges $0.0081/min after an initial $9.97 monthly fee.
For their money, users can expect the HD voice, call forwarding and number porting features offered by most VoIP services, as well as more rare call analytics tools that can display an operation's call usage in graphs. Customers are not charged setup fees or given annual contracts. A reliable and cost-effective choice for businesses that aren't making calls outside of the US and Canada.
- Call forwarding
- Call analytics
- HD voice quality
- Analytical tools
- No annual contracts
- Unlimited minutes
MegaPath allows businesses to streamline IT management through the combination of voice and internet access while reducing costs. The plans offered by MegaPath allow customers to purchase what they need which is based on the calls that your business will process.
Broadband can be purchased from the company or you can integrate the system with your own broadband provider. The system also comes with a router/IAD to support QoS, security and quality monitoring to ensure the best call standards. What’s more, with MegaPath you can use your existing telephone equipment and IP network which enables businesses to save costs. Calling plans start at 500 minutes per month and you can carry over any allowances you haven’t used to the following month.
- Free Installation
- Great Prices
- Increase Network
- Integrates with existing equipment
- Carry over all allowances
- Fax compatible
Unified Communication and telephone services are delivered through SIP trunking using an IP network as a substitute for the normal telephone system. Using SIP trunking a VoIP user is able to make calls to any phone which belongs to a PTSN network without the need for telephone lines. Connections are established using a suitable hosted PBX solution.
There are three elements required for a SIP trunk to function properly. The first is the SIP provider who supplies the service, the second is a phone system with SIP enabled capabilities and thirdly a border element. This border element enables the connection between the enterprise network and the PTSN or an IP network.
The elements are often managed by the SIP trunking provider and they can be either a switch or firewall. Using these three basic components, a business is able to significantly improve its reach in terms of communications. If an IP-PBX has already been installed this will facilitate the process even more.
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