How to Tell If the Problem Is Your ISP or Your Equipment

Problem Overview

When the internet goes down or slows to a crawl, the first question every business owner asks is the same: is it my ISP or my router? It matters, because the fix is completely different. If the problem is on your internet provider's side, no amount of rebooting your own gear will help, and you should be on the phone with them. If the problem is your own equipment, you can often fix it yourself in a few minutes, and calling the provider just wastes everyone's time.

The good news is that you do not need to be technical to figure out which side the problem is on. Over years of servicing business circuits and office networks, the pattern is almost always the same: a few simple, safe checks will point you to the right culprit. This guide walks you through those checks in plain English, in the order a field technician would actually run them.

Common Symptoms

• No internet on any device, even though the power is on.
• Internet works on some devices but not others.
• Pages load slowly or time out, even though your speed plan is fast.
• Wi-Fi shows as connected, but nothing actually loads.
• The connection drops and comes back repeatedly throughout the day.
• VoIP calls cut out, sound choppy, or drop entirely.
• One specific application or website fails while everything else works.

Most Likely Causes

When deciding is it my ISP or my router, these are the usual causes, listed roughly from most common to least common in a small office:

• Your own router or Wi-Fi (most common). A router that needs a restart, an overloaded Wi-Fi channel, or a device too far from the access point causes the majority of "the internet is down" calls.
• A loose or damaged cable. A network cable knocked half-out of the wall or modem looks like a total outage but is purely physical.
• The modem (the box your provider's line plugs into). Modems occasionally lock up and need a power cycle, or lose sync with the provider.
• Your ISP's line or equipment. A provider outage, a problem at the street, or maintenance on their network. Real, but less frequent than people assume.
• A single device or its settings. If only one computer or phone is affected, the network is fine and the device is the issue.

Step-by-Step Troubleshooting

Run these in order. Each step either fixes the problem or rules out one side, so by the end you will know whether to keep working or call your provider. Everything here is safe to do yourself.

1. Check whether more than one device is affected. Try the internet on a second device, ideally one on Wi-Fi and one on a cable. If only one device fails, the network is fine and the problem is that device. If everything fails, keep going.
2. Look at the modem lights. Walk to the box where your provider's line enters the building. Most modems have labeled lights such as Power, Internet or Online, and a signal light. A steady (not blinking) Internet or Online light usually means the provider's signal is reaching you. A blinking or off Internet light, or a red light, points strongly toward the provider's side.
3. Check the physical cables. Make sure the cable from the wall into the modem, and the cable from the modem into the router, are firmly seated. You should feel a small click. Reseat any cable that looks loose. Do not force anything.
4. Power-cycle your equipment in the right order. Unplug the modem and the router from power. Wait about 60 seconds. Plug the modem back in first and wait until its lights settle (often a minute or two). Then plug the router back in and wait for it to come fully up. Order matters: the modem must reconnect to the provider before the router can hand out internet.
5. Test directly from the modem (the key isolation test). This is the single most useful step for answering is it my ISP or my router. Connect one computer with a network cable straight into the modem, bypassing your router entirely. If you have a business modem-router combo, this may not apply, but for a separate modem it does. If the internet works plugged straight into the modem, your provider is fine and your router or Wi-Fi is the problem. If it still does not work directly from the modem, the problem is almost certainly the modem or the provider's line.
6. Check for a provider outage from another connection. Using your phone on cellular data (turn Wi-Fi off on the phone first), search for your provider's outage page or status checker, or call their support line and listen for a recorded outage notice. If they confirm an area outage, you have your answer and there is nothing to fix on your end.
7. Note the time and pattern. If the connection drops at the same time every day, or only under heavy use, write that down. Intermittent patterns are valuable clues, and they are exactly what your provider will ask about if you do need to call.
8. If only Wi-Fi is the problem, move closer and retry. If devices on a cable work but Wi-Fi is flaky, stand next to the router and test again. If it works up close, you have a Wi-Fi coverage or interference issue on your side, not a provider issue.

By the end of these steps you will fall into one of two camps: the internet works when plugged straight into the modem (your equipment or Wi-Fi is the issue, and that is in your control), or it does not (the modem or your provider is the issue, and it is time to call them).

When to Call Support

Call your internet provider when the evidence points to their side. Specifically, reach out when:

The modem cannot get a steady Internet or Online light after a full power cycle. A computer plugged straight into the modem still has no internet. Your provider's status page or phone system confirms an outage in your area. Or the connection drops repeatedly every day at predictable times, which often indicates a line or signal problem they need to test remotely.

When you call, you will save a lot of time by telling them what you already checked: that you power-cycled the equipment, what the modem lights show, and the result of plugging straight into the modem. That tells them you have done the basics and helps them escalate faster.

Call an IT professional or managed service provider instead when the internet clearly reaches your building (modem is online, direct connection works) but your own network, Wi-Fi, firewall, or phone system is misbehaving in ways the steps above did not resolve. That is a configuration or hardware issue on your side, and a provider's support team will not troubleshoot your internal network for you.

Prevention Tips

• Label your equipment. Put a small label on the modem and the router so anyone in the office knows which box is which during an outage.
• Know your normal. Note what the modem lights look like when everything is healthy, so a wrong light is obvious later.
• Keep a backup way online. A phone hotspot or a separate cellular connection lets you check for provider outages and keep working for short periods.
• Restart equipment occasionally. A periodic, scheduled reboot of the router during off-hours clears small glitches before they become outages.
• Protect the gear with surge protection. Power surges quietly damage modems and routers; a good surge protector or UPS extends their life and keeps you online through brief dips.
• Document your provider details. Keep your account number, support number, and circuit or service ID somewhere easy to find so you are not hunting for them mid-outage.
• Keep cables tidy and secured. Cables that cannot be kicked or yanked out do not cause mystery outages.

Frequently Asked Questions

How do I know if my internet is down or just my router?

Plug one computer with a cable straight into the modem, bypassing the router. If the internet works that way, your router is the problem and your provider's line is fine. If it still does not work, the issue is the modem or the provider. The modem's Internet or Online light is the other quick tell: steady usually means the provider's signal is present.

Why is my Wi-Fi connected but there is no internet?

"Connected" only means your device reached the router, not that the router has a working line to the internet. Check the modem lights and try the direct-to-modem test. If devices on a cable also have no internet, the problem is upstream of your Wi-Fi, often the modem or the provider.

Should I reset my router or call my ISP first?

Power-cycle your own equipment first, since it is fast, free, and fixes a large share of outages. Power-cycle the modem first, then the router. Only call your provider if a direct connection to the modem still fails or the modem cannot get a steady online light, which points to their side.

How long should I wait before assuming it is an ISP outage?

After a full power cycle, give the modem a few minutes to fully reconnect. If it still cannot get online and a direct connection fails, do not keep waiting blindly. Check the provider's outage page from your phone on cellular data, or call them, rather than rebooting over and over.

Related Articles

• How to Troubleshoot Internet Outages Before Calling Support
• Why Is My WiFi Connected but Not Working?
• How Do I Restart My Network Properly?

The NTC Tech Desk publishes practical, plain-English technology guides for small businesses. If this helped, subscribe for more field-tested troubleshooting articles.