VoIP Resources VoIP Solutions VoIP Troubleshooting Tips

What to Do When Your VoIP Service Goes Down

by Kevin Bartley

Here are five steps you can take if your VoIP service is down before contacting support to make sure that the disruption is not originating from your office.

Losing VoIP service can negatively impact every facet of your business. Service disruptions can result in lost opportunities, anger existing customers, and diminish your ability to communicate internally.

Service outages are sometimes caused by service provider network issues, but other times the disruption originates from inside your office. Instead of immediately contacting your provider's support team whenever your VoIP service goes down, try troubleshooting the issue on your own to identify the root of the problem.

Here are six steps on what you can do, on your end, when your VoIP service goes out.

1. Make Sure Everything Is Plugged In

It might seem like a no brainer, but a good first step is to do a quick sweep of your routers, modems, and phones to make sure that all the cords are plugged into the right sockets. A stray power cord could knock your entire phone system offline. You don't want to go through hours of troubleshooting only to find that the modem was unplugged the whole time.

2. Check Your Internet Connection

If your VoIP phone system has gone down, there's a good chance that your office Internet connection has failed. A quick way to see if your Internet connection works is by attempting to load a website in your browser window. If the page loads, your Internet connection isn't to blame for the outage.

If the page doesn't load, test your WiFi connection by plugging your computer directly into your cable or DSL modem with an ethernet cord. Some manufacturers recommend unplugging and resetting your modem before doing this. If you're still not getting a connection, that means that your office Internet is likely down. In the short term, call your ISP and lodge a service request. In the long term, consider switching to a more reliable business Internet service.

If you frequently experience disruptions to your VoIP service due to Internet connectivity, we recommend running a VoIP test to check for jitter, latency, and/or packet loss. All of these issues can degrade the quality of the call, perhaps to a point where nothing intelligible is heard on either end.

The average VoIP call requires 100kpbs of bandwidth. If your network experiences a lot of simultaneous calls and usage, you may have to talk to your ISP about amping up your bandwidth threshold. In some cases, employees will inappropriately download large files with file sharing clients. Make sure the office Internet policies are clear so there's no confusion on what constitutes proper use.

3. Rule Out Router Issues

If your Internet is in fact working, and it's not suffering from crippling bandwidth issues, then it's time to take a look at the routers in your office. You can usually fix problems with your router by adjusting standard features on an Admin portal, although there are some exceptions.


Updating a router's firmware can reset or change critical network features without your knowledge. First of all, make sure that the firmware type is supported by your service provider and the VoIP phones you use. On occasion, certain firmware updates can obstruct VoIP traffic and disable phones that worked with earlier versions. If you're experiencing a service outage right after updating router firmware, you may want to consider switching back to the older version.


NATs (Network Address Translations) and firewalls are designed to block certain data packets from entering a network. Sometimes NATs and firewalls implement ALGs (Application Layer Gateways) designed to block VoIP packets. Even without an ALG, a firewall can inadvertently block benign traffic if certain settings are implement improperly. Consult your provider's online support center or Knowledgebase to find out how to disable these blockers and optimize your routers so they're compatible with the VoIP service.

Hardware Failure

Although this situation is less likely, it is possible that your network hardware has deteriorated or malfunctioned to a point where quality calls are not possible. There's no surefire way to test for this. But if your router seems unreasonably hot, or the power supply is having major issues, you might have to swap out the failing device for another model. You can view our recommendations in this Top Router guide.

4. Verify Phone Configuration

If your routers and your Internet are functioning properly, the final step is to check your IP phones. Many issues are phone specific, and there are plenty of resources online that detail the quirks of each device. However, there are some general guidelines that are helpful for any SIP phone.

First, make sure the phone is plugged into a power source. Many phone failures are simply attributed to misplaced power cords. If your phone uses Power Over Ethernet (POE), move the phone's ethernet cord into a different jack. If other phones are not having trouble powering with these outlets and jacks, that's a sign that your phone has malfunctioned and needs to be replaced.

If your phone has LAN connectivity and an IP address, launch a command window on your computer, and try to ping the URL and IP address your phone is registered to. If you can ping the IP address but not the URL, it's likely that your ISP's DNS server is down. If you can't ping either the URL or IP address, then something is wrong with the network routing. In that case, refer to Step 4 on router issues.

Make sure your phones are registered, and monitor them closely after you upgrade any firmware. As a last resort, you can power cycle the devices. Unplug the phones, routers, and modems for over a minute, and then plug them all back in, starting with the modem, then the routers, then the phones.

5. Look for Network Alerts

If you know that your Internet, routers, and phones are working fine, it's time to see if a network alert has been posted. Most service providers typically have a network page where they post the current status of their network. Check this webpage to see if there are any outages or issues that the provider is aware of.

You can also go to your VoIP provider's Twitter, Facebook, and other social media to see if there are any recent mentions of a network issue or service advisory.

6. Contact Service Provider’s Support Team

If you've tried the steps above, and you're still experiencing a service outage, it's time to call your VoIP service provider's support team. You're probably not suffering from common network problems at this point. The outage is most likely on your service provider's end, and it's time to let the experts take over.

When you call a support agent, detail to him or her the steps that you've already taken on your own. That way, the support agent can weed out these basic problems and start to look at the real issue. This saves you from all the back and forth of phone tag, and allows your customer service agent to start helping you in the way you need it.

Of course, you can contact a customer service agent at any point during your service outage. If you feel completely flustered, don't hesitate to pick up the phone; that's what you're paying your service provider for. When routers, phones, and Internet connections are all intertwined, a single missing piece of the puzzle can cause your phone system to go down. You can usually save time if you follow through with some of these tips before you contact customer support.

Learn more about VoIP Solutions