Is an SIP Trunk More Reliable than a PRI?

If your business is looking to purchase a new phone system, you’re probably debating between an SIP trunk and a PRI T1 line. Both systems perform the same function i.e. they allow a company to make and receive phone calls. However, there is a vast difference between them in terms of functionality, cost, features, and the underlying technology.

Depending on who you ask, you will get different answers about SIP versus PRI. For a long time, the latter won on the basis of call quality and reliability alone. If you had large call volumes or voice was mission-critical to your organization, PRI was the best choice no questions asked. But times have changed. VoIP technology has matured to the point where the distinction is not so clear-cut.

What Is the More Reliable Option?

There are lots of ways you can compare the two. But you are most concerned about reliability and call quality. Suppose you really want to know if an SIP trunk is as reliable as a PRI line. The answer is no. Actually SIP trunks are more reliable than a PRI line in today’s world. Surprised? Don’t be. There’s a reason SIP trunks are widely considered to be less reliable.

If your SIP trunks are delivering calls over the public Internet, it is definitely not reliable. If you don’t have sufficient speeds or bandwidth, call quality and reliability will suffer. And this is the option most people think of when comparing SIP trunks and PRI lines.

If you want to guarantee reliability – not to mention call quality – it is best to use SIP trunking over a dedicated circuit or Internet connection. Make sure you have sufficient bandwidth for simultaneous calls during peak hours. Check that your Internet speeds can support both data transfer and voice calling at the same time.

Now, your SIP trunks can easily match PRI lines for reliability and call quality. However, SIP trunks have a few other benefits that make them more reliable overall.

Disaster Recovery: Failover Options

Do you have a disaster recovery plan for your business? Does this include your phone system? No matter how reliable you think your systems are, they can and will fail sometime. This is why providers offer failover options for both PRI and SIP trunks. In the case of PRI, you can designate one phone number as an alternative when your main phone lines are down.

SIP providers give you more options. You can designate to or even more phone numbers or IP addresses as failover options. What does this mean in a real-world scenario? You can set up your phone system to route incoming calls:

• To your dedicated circuit
• Then to your backup Internet connection
• To another company site as a third option
• Finally, to a mobile phone number as a last resort

With these many options, you may not even notice that your primary line is down for hours! It doesn’t matter if you lose power or Internet access. Your phones will keep working. How’s that for reliability?

Call Capacity: Simultaneous Calls

This is another important consideration when setting up failovers. How many simultaneous calls can you forward to your failover option? With PRI, you have to pay for each failover call path. So if you want to have five simultaneous calls, you have to pay for five call paths each month. Even if you don’t use them at all!

With SIP trunks, there is no limit on the number of simultaneous calls. As long as you have the bandwidth, no caller will get a busy signal if your primary connection goes down.

Location Flexibility

PRI lines are tied to a physical location. It means your failover phone number should be in the same area as your PRI line. SIP trunks have no such restrictions. Suppose your company has five offices distributed all over the country. Failover options can be anywhere as well. So let your office in another time zone handle calls while the primary site recovers from any problems. This option also tips the scale in favor of SIP trunking.

DID Routing

When you use the failover option with PRI, you lose all DID routing. That means all calls will go to the single number you designate. It’s a surefire way to confuse callers, especially during an emergency.

With SIP trunks, you keep all your routing rules for calls. If your company has many employees with DIDs such as salespeople, you’ll definitely want incoming call routing.

As you can see, SIP trunks are just as reliable as PRI lines in a narrow context. From a disaster recovery and overall business perspective, the former beats the latter hands-down. Provided your system is configured correctly, you should have fewer issues with SIP trunks than any other system. So what are you waiting for? Get started by calling SIP trunk providers today!