Buffering, also known as stuttering, is one of the most annoying problems that can occur when streaming video or audio online. Nothing is more frustrating than waiting for a video to load while that spinning wheel icon endlessly circles. But what actually causes buffering? Is the issue with your modem or your router? Getting to the root of the problem is key to resolving buffering issues. In this article, we’ll examine the difference between modems and routers, what buffering is, and whether the modem or router is the culpable party when it comes to streaming interruptions.
What is a Modem?
A modem is a hardware device that allows a computer or other network device to connect to the internet. The term modem stands for “modulator-demodulator” as modems convert analog signals that travel through telephone lines, cable connections, or fiber optics into digital signals that can be understood by computers and other digital devices.
Modems have a WAN (wide area network) port that connects to an internet service provider (ISP) via a telephone line, coaxial cable, or fiber optic connection. They also have a LAN (local area network) port that connects to devices in the home like computers, routers, game systems, and streaming devices via an ethernet cable or WiFi connection.
The modem’s job is to convert information from your ISP into data that your home network can understand and process. So in essence, the modem is what provides the actual internet to your home network.
Types of Modems
There are a few different types of modems:
- DSL modems connect to the internet via telephone lines. DSL stands for digital subscriber line.
- Cable modems connect to the internet through the same coaxial cables that deliver cable TV service.
- Fiber modems connect to the internet via fiber optic cables for the fastest speeds.
- Satellite modems connect to the internet using a satellite dish installation.
- Mobile hotspot modems provide internet connectivity through cellular networks for WiFi on the go.
Most home internet service from cable or phone companies will supply a combination modem/router device that handles both jobs.
What is a Router?
While the modem is responsible for connecting your home network to the worldwide web, the router takes that internet connection and shares (aka “routes”) it among all the devices in the home that need access.
Routers have both WAN and LAN ports similar to modems. The WAN port connects to the modem to grab that incoming internet signal. The LAN ports and WiFi connectivity allow networking between devices like computers, phones, tablets, printers, game systems, and streaming devices so they can all access the internet through the same connection.
Some key jobs handled by a router:
- Distributes the internet connection from the modem to devices in the home network.
- Allows networking and connectivity between devices on the local home network.
- Provides WiFi connectivity.
- Assigns IP addresses to networked devices in the home.
- Enables firewall security to protect the network.
Routers give you extended configuration options like WiFi channels, security protocols, and parental controls. So they provide a lot more customization of your network compared to relying solely on the modem.
What Causes Buffering?
Buffering occurs when a network-enabled device like a streaming stick, game console, or smartphone pauses downloading media while more data transfers. You’ll usually see a loading wheel symbol spinning in the middle of a frozen video frame when buffering is happening.
Buffering is often caused by:
- Slow internet speeds and bandwidth issues
- WiFi dead zones or weak signal strength
- Outdated networking equipment like the modem or router
- Too many high-bandwidth activities happening at once on the network
- Distance between streaming devices and the router or modem
- Outages or connection issues with your ISP
So in many cases, buffering can result from problems with both the modem and router together. Other times the root cause may be directly attributable to just one or the other.
How Can the Modem Cause Buffering?
If the modem itself is outdated, malfunctioning, or not supporting the speeds you’re paying for through your ISP, that can manifest in the form of buffering across your network. Here are some specific modem-related issues that lead to buffering:
Older Model Modem
If your modem is an older model purchased 5+ years ago, it may not support the faster internet plans available today. For example, DOCSIS 2.0 modems can’t handle speeds above around 40 Mbps. So if you upgrade to a 100 Mbps or 200 Mbps cable internet plan without upgrading the modem, that speed mismatch results in regular buffering.
Faulty Modem Hardware
Like any electronic device, modems can malfunction. Connection issues, overheating, firmware problems, and other glitches with the modem can interrupt the internet signal causing buffering. Unplugging the modem and plugging back in can temporarily resolve these types of hardware errors. But replacing the modem may be required if problems persist.
Bandwidth Overload
Modems have a maximum bandwidth capacity. Standard models support around 400 Mbps total throughput. So if there are multiple high-bandwidth activities occurring simultaneously across your network devices, the total load can exceed the modem’s capabilities. Video streaming in 4K uses around 25 Mbps per stream, as an example. So a few streams plus large software downloads can overwhelm the modem and lead to buffering.
Incorrect Configuration
Your ISP configures the modem remotely with optimal settings for your internet plan. But sometimes the configuration can get corrupted. Missing settings like DOCSIS channels or security protocols will result in buffering. Your ISP should be able to diagnose and correct any configuration issues with the modem if this is the problem.
Line Quality
For DSL connections, the telephone line between your home and the ISP hub can deteriorate over time and degrade the internet signal. This causes packet loss and high latency that will interrupt your streaming with buffering. Your ISP would need to send a technician to assess the line and replace any damaged portions.
Network Congestion
Like any pipe that can be overfilled, network congestion happens when too many subscribers in your neighborhood max out the bandwidth capacity of the local ISP servers and nodes. Peak evening hours are often congested. Unfortunately, this is an issue your ISP needs to resolve by upgrading infrastructure.
How Can the Router Cause Buffering?
A faulty or misconfigured router can also be the root of your buffering woes. Here are some key factors related to the router:
Outdated Router Firmware
Manufacturers release firmware updates periodically to fix bugs and optimize performance. If your router firmware is over 6 months old, limited buffering issues may occur on modern devices. And firmware over 2 years old can be completely incompatible with new devices like WiFi 6 phones, leading to frequent buffering.
WiFi Dead Zones
If the router’s WiFi signal cannot adequately reach your streaming devices, that weak unreliable signal connection will interrupt streaming with buffering pauses. Adding WiFi extenders is the best way to fill WiFi dead zones in the home.
Old Router Model
As with modems, routers can become outdated as internet speeds and WiFi standards improve. For example, 802.11n routers max out at 450 Mbps total throughput. So they will bottleneck modern WiFi 6 devices like smartphones and tablets that require higher bandwidth capacity. Upgrading to a contemporary router model prevents buffering in these cases.
Too Many Connected Devices
Routers have a limit on the number of devices that can be simultaneously connected to the network. Budget routers might only support 10-15 devices at once. Connecting more WiFi and ethernet devices than the router allows for will certainly lead to buffering galore.
Router Placement Issues
The router’s physical location in the home can impact WiFi performance and cause buffering for wireless streaming devices. Placing the router in a cabinet, the basement, or other periphery will limit signal strength where it’s needed most. Centrally locating the router provides optimal WiFi coverage.
Diagnosing and Resolving Buffering Issues
Determining whether the modem or router is responsible for buffering generally requires running through some diagnostic steps:
Check Modem Connection Quality
Use the internet speed test tool available through your ISP account portal. This will analyze factors like download/upload throughput, latency, jitter, and packet loss. If speeds are significantly lower than your plan provides or you see high latency and packet loss, that points to a modem issue.
Update Modem Firmware
Log in to your modem’s administrative interface and check the current firmware version. If it’s over 6 months old, contact your ISP to have them remotely push the latest firmware update to the modem.
Scan for WiFi Signal Issues
Use a WiFi analyzer app to heatmap signal strength throughout your home. Dead zones and weak signals in high traffic areas indicate a need for WiFi extenders or repositioning the router.
Count Connected Devices
Log in to your router and view all connected devices. Having more connections than your router allows will lead to buffering. Note that some devices like smart lights may connect multiple times.
Check Router Hardware Health
If your router frequently requires rebooting, runs extremely hot, has damaged ports, or other physical symptoms, a replacement router may be needed.
Based on the diagnostics, you’ll know whether it’s the modem, router, or both that require troubleshooting. Here are tips for resolving the issues discovered:
- For modem bandwidth overload, reduce simultaneous streaming across devices.
- To fill WiFi dead zones, strategically add mesh extenders.
- Upgrade outdated modem and router models to support faster internet plans.
- Relocate the router to a central home location for optimal WiFi coverage.
- Spread out devices over both router 2.4Ghz and 5Ghz bands to prevent network congestion.
- If ISP line quality is poor, request a service call to fix physical connection issues.
Conclusion
In summary, both the modem and the router play an integral role in delivering smooth streaming without buffering pauses and interruptions. An outdated, misconfigured, or faulty component in either device can be the culprit. Running through some diligent diagnostics will determine if the modem or router needs attention. Often basic troubleshooting steps like updating firmware, relocating devices, and reducing bandwidth strain will prevent the buffer wheel from ever spinning again! Consider replacing very old modems and routers that cannot handle modern internet demands for long-term buffering relief.