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How To Choose the Right SIP Trunking Provider

A Guide for Choosing the Right SIP Trunking Provider

If you’re considering a SIP trunking solution for your business, you probably started looking in the same place that everyone else does: the Internet!  And when you searched for “SIP trunking provider,” we’re willing to bet that you saw at least 10 providers on the first page of search results.

With so many SIP trunking providers to choose from, it can be tough to know if you’re making the right decision for your business – especially if you’re not familiar with the terminology used by the cloud communications industry.

In this quick guide, we’ll help you understand how to choose the right SIP trunking provider and highlight some of the key questions that you should ask as you research your options.

A Quick Review: What Is SIP Trunking?

With an array of acronyms like SIP, VoIP, and PBX, cloud communications (and SIP trunking, in particular) can seem a little intimidating. Here’s a quick overview of some of the key terms you need to know:

SIP, which stands for Session Initiation Protocol, is a signaling protocol that is most commonly used for Internet conferencing, telephony, and instant messaging.

SIP trunking is a cloud communications service that is used to connect a PBX (Private Branch Exchange) to the Internet for the purpose of low-cost voice communications.  In essence, a SIP trunk channel replaces a traditional phone line.

Now, for the real question: how can SIP trunking help your business?

SIP trunking offers your business the chance to save money on local and long distance calls without having to replace your existing phone system or PBX.  With a SIP trunking solution, you’ll experience lower communications costs without sacrificing call quality (or efficiency).

What to Look for in a SIP Trunking Provider


Every incoming and outgoing call is key to your business’s success.  And while many SIP trunking providers say that they can provide 99.99% uptime, not all of them have the preventative measures in place to back up that claim.

When we say that you should choose a reliable provider, we mean that you should look for the following characteristics:

Direct Interconnects with Tier 1 Providers

Some SIP trunking providers choose to purchase connections and routes from intermediate carriers rather than forging solid relationships with tier 1 providers.  If something goes wrong and the network goes down, these providers have to contact the reseller, who then has to figure out where the failure occurred.

Simply put, a SIP trunking provider that uses direct interconnects with tier 1 providers can provide a higher level of reliability for your business.

Fully Redundant Call Routing and Failover Provisions

In case of natural disasters and technical outages, it is always a good idea to have a SIP trunk provider that offers fully redundant call routing and failover provisions.  If the worst happens and the network goes down, these preventative measures will ensure that you don’t miss a customer call.


“Scalability” has become a bit of a buzz word.  But what we mean is simply this: as your company grows, your SIP trunking solution has to be able to grow along with it.

A well-equipped SIP trunking provider can easily add or remove lines as your business needs change.  The best providers can provision these lines in as little as 24 – 48 hours.

Keep in mind that as your provider adds or removes lines, you may need to adjust the amount of bandwidth that you’ve allocated for VoIP (Voice over Internet Protocol) calls.  A good provider can help you plan for these needs and ensure that you’re able to scale up or down easily.


Since SIP trunking services run over the Internet, they are a cost-effective and scalable communications solution for businesses of all sizes. But, the cloud comes with its own potential problems, and security is one of them.

When you’re searching for the right SIP trunking provider, be sure to ask about the security measures they take to prevent security breaches, or toll fraud.  Well-equipped providers often take some or all of the following steps to guard against VoIP fraud:

Credit Limits

Although it might seem odd, credit limits are a great way to prevent international toll fraud.  For example, if your SIP trunk or PBX is compromised and a hacker tries to place fraudulent, expensive calls, a credit limit ensures that your system will disconnect and block any further traffic.

Call Barring

Call barring allows you to block or modify access to certain nations or destinations.  This is especially important, since most toll fraud occurs when hackers make expensive, long-distance calls via your cloud-based phone system.  This feature allows you to have real time control of your traffic and protect against potential fraud.

24/7 Anti-Fraud Monitoring

The best SIP trunking providers have sophisticated algorithms in place that are designed to detect fraudulent VoIP activity.  At the first sign of trouble, they’ll be able to take action and prevent any further problems.

Options for Additional Features

When it comes to enhanced calling features and functionality, not all SIP trunking providers are created equal.  It is important to research which features are most important to your business so that you can choose a provider that offers them.

Below, we’ve listed some of the features and resources that many SIP trunking providers offer:

  • Account Codes: a dialed code that can track calls
  • Audio Conferencing: audio conferencing services for the company
  • Auto Attendant: automatic receptionist for incoming calls
  • Disaster Recovery Routing: pre-set backup routers in case of emergency.
  • Telephone Numbers (DID): inbound and outbound calling with a DID number
  • Forwarding Numbers: forward number from one DID to another
  • Growth Reserved Numbers: reserve numbers for when the company has future growth
  • Toll Free Calling: Toll free numbers will be used with IP addresses instead of DID numbers.
  • Voicemail Box: Voicemail services for telephone number

Stellar Customer Support

If you’ve chosen a SIP trunking provider that meets all of traits listed above, you shouldn’t have to worry about problems with call quality, reliability, or uptime.

But if problems do arise, you want to be sure that someone will be there to help you right away.  We recommend choosing a SIP trunking provider with a support team that is available 24/7 to answer any questions or help out with urgent concerns.


Although choosing the right SIP trunking provider might seem like an overwhelming task, it’s not as hard as it looks!

If you have a clear understanding of your business’s communications needs and keep the criteria we outlined above in mind, you’ll have all the tools you need to make the right choice.

Looking for more information about SIP trunking?  We think you might be interested in the articles below:

Caitlin Burge

Caitlin Burge

Content Specialist at AVOXI

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