What to Do About SIP/VOIP Systems When the Internet Goes Down
When internet down

SIP telephone systems can free your staff from being tied to their desks. You know that SIP comes with many benefits for everyone in your organization. Still, what do you do when your internet goes down, taking your SIP phone system with it. 

Just about everyone relies on the internet in 2020. Without it, we all stare at each other with nothing to say, and it’s awkward. SIP opened a new world for business, so let’s look at solutions that keep your marketing team working and communication flowing.

Redundancy for When Your Internet Goes Down

The best advice when implementing a SIP telephone system is to hope for the best but be prepared for the worst. As you review system options and features, check to see what happens when the internet goes down. Redundancy can forward calls to assigned mobile devices in real-time, and this means you won’t miss a single call or sale. 

An excellent SIP provider will offer you alternatives, like a failover system, with multiple options for routing. For example, SIP.us offers a primary SIP trunk, and optional secondary SIP trunk and a PSTN forwarding option for when either of these fails. You want a provider that makes sure you are getting your calls no matter what happens.

Backup Internet Solutions

Rather than relying on a single internet provider, have a primary and backup internet solution and review all bandwidth options along the way. In this way, when your primary provider for the internet is down, you have another way to connect. Having other methods for your SIP system to connect is not only smart; it’s good business sense.

In one popular method, the internet connection to the business is split into two individual networks. Two separate ISPs support these networks, and one provides service to the SIP system while the other provides service to the computers. During an outage, the SIP system automatically switches over to the other ISP.

Another popular method is to have primary and backup internet connections that support both networks simultaneously. Both are plugged into a simple router and automatically switch over to the backup ISP when the primary link is unavailable or down. Using either method is practical and ensures there’s no interruption in your SIP system and telephone communications.

Backup Connection Cable for Outages

Did you know that most internet outages are traced back to cable problems, either interior or exterior? Most interior related issues are easily solved by replacing or reconfiguring the faulty equipment, whether they be cables, routers, or computers. However, exterior problems, usually called “the last hundred yards,” by most experts, are relegated to the public switched telephone network (PSTN). 

If the issue is the connection between your office and the PSTN that can be caused by roadwork or environmental issues, the result is the internet goes down. There is a solution to avoid this, but it won’t come cheap. You can run a private line from your office and the PSTN, and this should insulate you from this type of problem.  

Troubleshooting Typical SIP Issues

Connectivity has come a long way, but that doesn’t mean there will never be an issue. Since your SIP system relies completely on your internet connection, being familiar with troubleshooting methods for your network, in addition to interruptions or total outages, can be helpful. The complete failure of a network can be caused by power outages, poor network connections, internet outages, or even overcrowding on the network.

With your business relying on your SIP system for telephone service, it is urgent to ensure your network doesn’t fail. Still, when it inevitably does, you need to have it back up and operating as quickly as possible. Here are a few areas that can help:


In the most basic setup, you will have an internet modem connected to its source with a cable, and the computers, in turn, will be connected using a series of wires and switches or routers. You may have a wireless network as the last step to connect computers and devices to the network, but the rest is cables. 

  • Make sure you have complete end-to-end connections
  • Look for cables that are damaged

Router Settings

Make sure that you not only have a compatible router, but it is also properly configured and optimized. Even though most routers will be excellent, it is a wise idea to make sure that your specific router can optimize your SIP connection, and allow the proper flow of data through the network. Using the same brand (and model where possible) also simplifies things when troubleshooting problems.

  • Try resetting your router
  • Check QoS settings
  • Check port forwarding settings
  • Have dual-band routers where possible

Packet Losses

While losing packets on your networks won’t result in the complete failure of your system, it can affect call quality for your SIP system. The fix depends on the cause, but if it is traced back to your ISP, then there’s not much you can do to correct the problem on your end. A third party test will help you determine whether your network is experiencing packet losses and to what extent. 

The most common cause is network congestion; however, bad cables or hardware can also play a role. 

When to Call ISP Support

After checking all the possible causes, sometimes there’s nothing you can do on your own. Since the only answer is to reach out to the most likely suspect, that’s what you do. It’s all a process of elimination, and once you’re there, you’ll know it.

Troubleshooting on your own allows you to rule out regular problems. If, after router reconfigurations and cable replacements, your still down, contact your ISP provider to check it out.

Find Out More

If you’ve recently decided to cut the cord and move to SIP trunks for your business telephone system, there’s a lot for you to figure out. At SIP.us, our professionals are ready to help you. Don’t wait until your internet goes down to make a call.

We’ve provided a few methods that keep your SIP system up during an outage of your primary ISP. When you want more information, there isn’t a better place to start than with a proven leader in SIP trunking.