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Enterprise SIP Trunking

Enterprise SIP Trunking

Software-driven, high-quality, elastic SIP trunking built-for-scale with integrated E911 support.

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The foundation of modern telephony

Get the reliable voice calling your customers want paired with more flexible usage-based pricing and the software tools you need to navigate your digital transformation.

Cloud phone call

Quality voice at scale

High quality calling at scale is never an issue with Bandwidth’s cloud-native carrier network. Plus with elastic, usage-based pricing you can consolidate legacy SIP vendors or eliminate costly, inflexible PRI lines.

Laptop with a dashboard

Software-driven number management

Our Dashboard & API suite make it easy to manage ports, order phone numbers, and get the real-time insights into telecom cost centers you need. Numbers can be provisioned instantly, better enabling workstation management.


Future-proof enabled

As the telecom power behind the majority of the UCaaS and CCaaS Magic Quadrant leaders, we’re best positioned to help enterprises navigate the rocky transition to cloud communications platforms, setting you up for success for years to come.

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Seamless 911 Integration

Leverage Bandwidth’s advanced E911 capabilities as you update your systems and infrastructure to ensure your enterprise maintains compliance with 911 regulations.

Cloud-ready, Enterprise SIP trunking

Leverage a full-featured SIP Trunking solution to give your enterprise the reliable, software-driven voice calling it needs.

  • Triggered ports
  • 100% US-based support
  • Flexible/Elastic pricing models
  • Burstable functionality
  • Instant number provisioning for workstation activation
  • Domestic and international long distance
  • Toll-free calling
  • SMS capable
  • Seamless E911 integration
  • Line features including directory listing and caller ID
  • 24/7 Network Operations Center (NOC)
  • Real-time disaster recovery and IP failover control
  • API enabled access to calling and billing detail records (BDR)

How can your business benefit from Enterprise SIP with Bandwidth?

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Centralize your SIP Services

Work with a migration partner, not just a service provider. Centralize your SIP trunking services on our software-centric carrier network and realize the benefits of greater control and visibility in the form of simpler UCaaS and CCaaS migrations.

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Make the move from PRI to SIP and get the scalability, security, and cost efficiencies your enterprise needs to continue growing.

Bring your own carrier

Bring your own carrier (BYOC)

Choose the carrier you want to plug into your contact center, conferencing, or unified communications platform.

See what our customers have to say about Bandwidth

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“Working with Bandwidth was a no-brainer for us because of their experience working with Microsoft to power Calling Plans. Their solution gave us all the tools and services we needed to successfully deploy Direct Routing and dynamic E911 for Microsoft Teams.” – Josh Jandrain, CIO Inclusa

Read the full customer story

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A better approach to support

Many claim to be support centric, but we prove it by just being easier to do business with. We hold ourselves accountable through SLA achievement and a near perfect CSAT benchmark, and focus on making sure you’re successful by staffing our dedicated support team with industry vets that have the expertise and experience to tackle the most demanding situations. You’ll wonder why everyone doesn’t have the same approach.

  • Named implementation specialist to usher you through a tailored migration plan
  • A dedicated team of porting experts so you have an easy migration experience
  • Dedicated support personnel to manage needs as you scale over time
  • 24/7 monitoring by our in-house Network Operations Center (NOC)
  • 98% CSAT achieved by our 24/7 Technical Assistance Center (TAC)
  • Industry experts that help navigate changing telecom requirements
  • Clear, always available escalation paths
  • Customer-driven prioritization of support tickets

Ready to get started?

Deliver scalable, cloud-ready calling with Bandwidth’s Enterprise SIP Trunking.

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Related resources

Frequently asked questions

What is SIP?

SIP stands for Session Initiation Protocol and is a protocol (i.e. language) that communications applications use to talk to one another over an IP network.

SIP is used to create, manage, and terminate calls (or sessions) in an IP-based network, SIP is the instruction set that tells an application how to process a phone call.

What is SIP Trunking?

SIP Trunking is a way to make voice calls over the internet. This communication method allows for Voice Over Internet Protocol (VoIP) calls to be made, for messages (SMS/MMS) to be passed, 911 emergency calls to be made, and other SIP-based real-time communications.

What are the benefits of SIP Trunks versus PRI?

The primary benefit of SIP trunks over PRIs is cost savings as this method is far more scalable, and generally comes with less fixed overhead costs.

SIP makes converged networks possible because it is an application, not a service. In the same way that copper lines transmit signals rather than create them, SIP allows any endpoint to communicate with another, as long as the two endpoints agree to use SIP. That means that a single-location company can converge its networks, roles, and equipment into one system that meets all of its communication needs. Convergence offers concrete benefits, in that:

  • Routers and switches are used more efficiently
  • Combined roles are enabled, so endpoints can both send and receive voice, data, and video
  • Networks can be mixed to integrate voice and applications
  • Costs are reduced because SIP is a virtual infrastructure
  • SIP Trunking removes the TDM Constraint and provides flexibility to manage at scale
  • Fewer or even just one SIP provider must be engaged

How does SIP trunking benefit your business?

Speed, agility, and leanness are guiding principles for companies that need to stay competitive today. And in order to support those principles,
businesses need technology that supports them as well. Compare SIP to traditional phone services and the advantages are clear.

SIP delivers significant savings. Traditional analog circuits are costly because they have to be designed, configured, maintained, and upgraded. SIP trunking provides the same call quality as traditional line, but since it runs over the Internet, it doesn’t require the same level of design and configuration. Plus, the maintenance and upgrades to the network would be necessary whether SIP trunking was being run through them or not.

The infrastructure costs for SIP trunking are also lower because SIP eliminates the need for primary rate interfaces (PRIs), which require enterprises to buy lines in bundles of 23. PRI customers who need 10 lines have to buy a bundle of 23, leaving 13 unused. SIP, however, can be purchased in whatever number of units a business requires.

Long distance, local inbound, and termination services can be included, providing another opportunity to save costs. Plus, SIP trunking delivers cost savings as great as 60% over traditional methods.

When should a business use SIP Trunking instead of a hosted solution?

A business should look to a SIP trunking provider when they decide that their needs are being met with a premise based PBX, but want the benefit of virtual circuits and more flexible pricing options.This system is often referred to as an IP-PBX (Internet Protocol private branch exchange). Coupled with SIP trunks, an IP-PBX serves up similar features to hosted solutions. SIP trunks typically save a business customer money over a hosted solution in that a SIP trunk can serve the needs of three to four employees, while a hosted seat is needed for each employee.

What equipment do I need to be able to use SIP Trunking?

Today many companies use SIP trunking to power the calling within their UCaaS and CCaaS platforms, but generally SIP Trunks can work with any SIP-ready hosted PBX system. SIP Trunks can also be made to work with a traditional analog or key phone system with an IAD (Integrated Access Device).

Is SIP here to stay?

With all the advantages that SIP trunking offers, why do any companies still use traditional services? It’s simple. Traditional telecom has been in existence for over 100 years. Over its lifetime, copper has been widely adopted, of course, and it’s the telephone technology that most of us grew up using. The short answer is: it was the best option that businesses have had until recent years. SIP trunking is only about 10 years old. That means it was purpose-built to work in today’s business environment. Since the advent of SIP trunking as a business tool, nearly 70% of decision-makers have adopted SIP, and of those adopters, 96% report satisfaction with call quality. A protocol can only achieve widespread adoption when it’s based on consistent standards. The guidelines for how a SIP trunk should work and interoperate with a phone system are defined and guided by the SIP Forum, an organization of telecom experts who work toward the continual improvement of SIP standards.

Does network ownership matter for SIP?

Network ownership does matter, particularly for larger organizations with higher call volumes. Large enterprises tend to see more call volume as they have more employees and customers that rely on underlying SIP services to do business. As the sheer volume of communications that are critical for doing business increase, so does the risk and potential cost assumed by the enterprise in the event of an outage. Therefore, it’s critical to pick a provider that is an actual carrier with ownership of the underlying network. This will allow the enterprise to maintain greater control and visibility into their services, as well as go directly to the source for resolution if there are ever issues or disruptions in service.

While most SIP providers are resellers that rely on several carriers, Bandwidth gives you direct-to-carrier access, meaning we cut out the middleman, giving you better support with deeper insights and faster results.

Industry leaders such as Google & Microsoft rely on Bandwidth because of our record of stability, innovation, reliability, and growth. Bandwidth is able to meet these challenges because we’re a Tier 1 carrier—we own and operate a nationwide network, with billions of minutes traversing it every month.