What Are Network Cables Used For? 10 Everyday Jobs Your Building’s Cabling Handles
Most people think of a network cable as the thing that plugs a computer into the internet. That is still true, but it is only a small part of the story. So what are network cables used for today? In a modern building, the same cabling carries data, phone calls, Wi-Fi, security video, door access, digital signage, and even the electrical power that runs many of those devices.
That shift has changed how businesses plan their buildings. This guide walks through the ten most common jobs network cables perform, which type of cable handles each one, and what to consider when planning cabling for a new or renovated space. Businesses looking for reliable network cabling services in Carson, CA can get professional help selecting and installing the appropriate cables for their network infrastructure.
Table of contents
- The short answer
- How network cables work
- Use 1: Connecting computers and sharing resources
- Use 2: Delivering internet service
- Use 3: Phone systems (VoIP)
- Use 4: Powering and connecting Wi-Fi
- Use 5: Delivering power with PoE
- Use 6: Security cameras
- Use 7: Access control and door security
- Use 8: Audio, video and digital signage
- Use 9: Retail and point-of-sale
- Use 10: Building systems and IoT
- Behind the scenes: backbones and data centers
- Quick reference table
- Planning tips
- Common mistakes
- Future trends
- Key takeaways
- FAQ
The Short Answer: What Are Network Cables Used For?
Network cables are used to carry data between devices, connect devices to the internet, and, increasingly, power the devices themselves. In a typical business, they support:
- Computers, printers, and file sharing
- Internet and WAN connections
- VoIP phone systems
- Wi-Fi access points
- Security cameras and access control
- Audio, video, and digital signage
- Point-of-sale systems
- Lighting, HVAC, and building sensors
The most common network cable is twisted pair Ethernet, such as Cat6 or Cat6A. Fiber optic cable links network closets and buildings, and coaxial cable still appears where some internet providers deliver service.
How Network Cables Work
A network cable is the physical path data travels between devices. Twisted pair copper cable sends data as electrical signals, while fiber optic cable sends it as pulses of light. Switches and routers direct that data to the right place.
Twisted pair cable can also carry power. Power over Ethernet (PoE) describes any of several standards or ad hoc systems that pass electric power along with data on twisted-pair Ethernet cabling. That single capability is a big reason network cables now do so many different jobs.
For a deeper look at cable types, see our guides to [the three main types of cabling](INTERNAL LINK) and [the most common type of network cable](INTERNAL LINK).
Use 1: Connecting Computers and Sharing Resources
The original purpose of network cables is still one of the most important: linking computers so people can share files, printers, and applications. That is the definition of a local area network. LANs facilitate the distribution of data and the sharing of network devices, such as printers. For businesses setting up a LAN, understanding the cable used in a local area network can help when selecting the appropriate cabling for reliable device-to-device communication.
In practice, network cables connect:
- Desktop computers and docking stations
- Network printers and copiers
- File servers and network storage
- Conference room equipment
Typical cable: Cat6 or Cat6A twisted pair from each wall jack to a switch in the telecom room.
Use 2: Delivering Internet Service
Internet service reaches a building over the provider’s cable, then passes through a modem or router onto the internal network. Network cables carry that connection from the router to switches and out to every device.
The cable at the service entrance depends on the provider. It may be fiber, coaxial cable for cable internet, or copper. Inside the building, twisted pair and fiber distribute the connection.
Typical cable: Carrier fiber or coax at the entrance, then twisted pair and fiber inside.
Use 3: Phone Systems (VoIP)
Most business phones today are Voice over IP (VoIP) phones, which send calls over the data network instead of dedicated phone lines. Each desk phone plugs into a network jack, and many also get their power from the same cable.
Phones were the first big driver of Power over Ethernet. Cisco developed and first delivered a proprietary version of PoE in 2000, to enable scalable and manageable power delivery to Cisco IP-telephony handsets. Today, VoIP phones remain a core use. One network testing company calls them the most common application, allowing phones to be powered directly from the wall jack.
Typical cable: Cat6 twisted pair with PoE from the switch.
Use 4: Powering and Connecting Wi-Fi
Wi-Fi may be wireless for users, but every access point is wired. Network cables carry the data between access points and the network, and usually power them too. PoE allows APs to be mounted on ceilings or high on walls for optimal signal coverage without needing a nearby AC outlet.
Newer access points need more bandwidth and power, which affects cable choice. TIA TSB-162-B, Telecommunications Cabling Guidelines for Wireless Access Points, recommends installing Cat 6A for horizontal cabling to WAPs.
Typical cable: Cat6A twisted pair, often two runs per access point location.
Key point: Good Wi-Fi coverage starts with good cabling. Access point placement is limited by where cable can reach.
Use 5: Delivering Power With PoE
Power delivery has become one of the biggest reasons businesses install network cable. PoE sends low-voltage DC power from a switch to connected devices, removing the need for an outlet at every device. Understanding the three main types of wires can also help readers distinguish between different wiring configurations and their typical applications.
The range of devices is wide. PoE power is used to run a wide variety of networked devices, including IP clocks, VoIP phones, surveillance cameras, access control panels, wireless access points (WAPs), point-of-sale machines, laptops, and digital displays.
Power levels have grown over time. Power over Ethernet has evolved from 15.4W (802.3af) to 30W (802.3at) to 60W Type 3 and 90W Type 4 under 802.3bt. Higher power brings more heat in cable bundles, which is why cable choice and bundle size matter for PoE-heavy designs.
Key stat: One chip manufacturer notes that any network device that consumes less than 90 watts is a candidate for PoE.
Typical cable: Pure copper Cat6 or Cat6A, with Cat6A recommended for high-power devices.
Use 6: Security Cameras
Network cables are now the standard way to connect security cameras. IP cameras send compressed digital video over Ethernet to a network video recorder, and PoE powers them from the same cable. PoE is widely used in surveillance systems to power IP cameras, allowing for easy installation in locations without nearby power sources.
Older analog cameras used coaxial cable, and many buildings still have coax runs in place. During upgrades, integrators often replace coax with twisted pair. Adapters can bridge the gap. Video baluns, or BNC-to-UTP adapters, enable coaxial cables to be replaced by category 5 or category 6 Ethernet cables.
Distance is the main limit. Ethernet runs are generally limited to 100 meters, so parking lots and large sites may need fiber or a closer switch location.
Typical cable: Cat6 or Cat6A with PoE, with fiber for long outdoor runs.
Use 7: Access Control and Door Security
Card readers, keypads, electric locks, and door sensors control who can enter a building. Network cables connect access control panels to the network and, increasingly, connect readers and controllers directly. PoE can be used to power IP cameras and access control systems. This allows flexible and strategic placement of security devices.
Many access control systems still use a mix of cable. Network cable connects controllers and IP-based readers, while multi-conductor cable often connects locks, door contacts, and request-to-exit sensors. See our guide on [what 3 core cables are used for](INTERNAL LINK) for more on those control cables.
Typical cable: Cat6 for controllers and IP readers, plus shielded multi-conductor cable for locks and sensors.
Use 8: Audio, Video and Digital Signage
Network cables carry video and audio to displays, projectors, speakers, and conference room systems. Two approaches are common.
AV over IP sends video and audio as network traffic, so any display on the network can receive a signal.
HDBaseT uses category cable as a dedicated video link. HDBaseT works by using a twisted pair of cables (like Cat 5e or Cat 6) to transmit video, audio, and other signals over long distances—up to 100 meters. It can carry several signals at once, transmitting video, audio, power, Ethernet, and control signals all through one cable.
Digital signage also runs on network cable. PoE supports digital signage installations in locations where running separate power lines would be challenging or costly, such as retail stores, airports, and public spaces.
Typical cable: Cat6 or Cat6A, following the AV equipment manufacturer’s cable requirements.
Use 9: Retail and Point-of-Sale
Retail stores rely on network cables for registers, payment terminals, inventory scanners, kiosks, and guest Wi-Fi. A dropped connection at checkout costs sales, so reliable cabling is a direct business need. PoE simplifies network installations by powering devices like wireless access points, security cameras, IP phones, retail Point of Sale (PoS) terminals, building access systems, PA systems, LED lights, VDI terminals, and digital signage over a single Ethernet cable.
Typical cable: Cat6 to each POS station, plus Cat6A for access points and cameras.
Use 10: Building Systems and IoT
The newest use for network cables is running the building itself. Lighting, HVAC controls, occupancy sensors, and environmental monitors are moving onto the network. The introduction of high-power PoE (802.3bt) has opened the door to advanced smart building applications, including intelligent lighting.
This convergence brings previously separate systems onto one infrastructure. Cisco notes that combining data and power in one cable will accelerate the consolidation of traditionally separate operational technology (OT) (such as HVAC, lighting, and security/alarming) with IT-managed devices.
Industrial sites use network cables for monitoring too. PoE allows for the smooth operation of sensors that track temperature, humidity, vibration, and other critical environmental parameters, ensuring optimal production conditions and predictive maintenance.
Typical cable: Cat6 or Cat6A for PoE lighting and sensors, plus shielded control cable for some HVAC and BACnet MS/TP systems.
Behind the Scenes: Backbones and Data Centers
Not every network cable connects to a device. Some carry the combined traffic of an entire floor or building. Backbone cables connect the main equipment room to telecom closets on each floor, and connect buildings on a campus.
These links typically use fiber optic cable because of its high bandwidth and long reach. Ethernet over fiber can run up to 100 km, far beyond copper’s 100-meter limit. Data centers and server rooms use large amounts of fiber and short copper connections between servers and switches.
Typical cable: Multimode or single-mode fiber for backbones, plus copper and fiber patch cords in equipment rooms.
Quick Reference: What Network Cables Are Used For
| Use | What the cable does | Typical cable | Uses PoE? |
|---|---|---|---|
| Computers and printers | Data connection | Cat6 / Cat6A | Rarely |
| Internet service | Carrier connection and distribution | Fiber or coax at entry, twisted pair inside | No |
| VoIP phones | Voice and power | Cat6 | Yes |
| Wi-Fi access points | Data and power | Cat6A | Yes |
| Security cameras | Video and power | Cat6 / Cat6A, fiber for long runs | Yes |
| Access control | Data, power, control | Cat6 plus multi-conductor | Often |
| AV and signage | Video, audio, control | Cat6 / Cat6A | Sometimes |
| Point-of-sale | Transaction data and power | Cat6 | Often |
| Lighting and sensors | Control and power | Cat6 / Cat6A | Yes |
| Backbones and data centers | Aggregated traffic | Fiber | No |
Planning Tips: Cabling for Everything Your Building Needs
Because so many systems now share the same cabling, planning for all of them together saves money and disruption. Use these steps:
- List every system, not just computers. Include phones, Wi-Fi, cameras, door access, AV, signage, POS, lighting, and building controls.
- Count devices and locations. Mark every outlet, ceiling device, and exterior mount on the floor plan.
- Identify PoE devices and power levels. Higher-power devices like access points, PTZ cameras, and displays favor Cat6A.
- Check distances. Keep device runs within 90 meters of a telecom room, or plan fiber and remote switches for longer reaches.
- Plan spare capacity. Extra drops cost far less during construction than after.
- Coordinate trades early. Security, AV, and IT vendors often each assume someone else is running the cable.
- Match jacket ratings to spaces. Use plenum or riser-rated cable where required.
- Certify and document. Test every run and label both ends.
If you are planning cabling for an office, warehouse, or retail site in Carson or the greater Los Angeles area, see our [Network Cabling Company Carson CA](INTERNAL LINK) and [Commercial Network Cabling Company in Carson, CA](INTERNAL LINK) pages.
Common Mistakes and Misconceptions
“Network cable is just for the internet.” Modern cabling carries phones, video, security, AV, and power. Planning for internet alone leaves gaps.
“Wireless means fewer cables.” Every access point needs cable, and faster Wi-Fi often means more of it.
Planning systems separately. When cameras, access control, and IT are cabled by different vendors at different times, buildings end up with duplicate runs and crowded pathways.
Ignoring PoE heat and power. Large bundles of high-power PoE cable can overheat. Cable type and bundle size matter.
Using cheap or non-copper cable. Copper-clad aluminum cable can fail with PoE devices and does not meet category standards.
Assuming low voltage means no license. PoE is low voltage, but in California, contracting for low voltage cabling work above the minor work threshold still requires a licensed contractor.
Exceeding distance limits. Cameras in parking lots or distant warehouse corners often exceed 100 meters. Fiber or a closer switch solves it.
Future Trends
- More devices on PoE. Lighting, sensors, displays, and even some laptops are moving to network power.
- Converged building networks. IT and building systems increasingly share one cabling infrastructure.
- Cat6A as the baseline. Higher Wi-Fi speeds and PoE loads are making Cat6A the default for new commercial work.
- Fiber moving outward. Larger buildings and faster uplinks are pushing fiber closer to devices.
- Coax continuing to fade. IP cameras and streaming video keep replacing coax-based systems.
Key Takeaways
- Network cables carry data, internet, voice, video, security, and power in modern buildings.
- VoIP phones, Wi-Fi access points, and IP cameras are among the most common PoE uses.
- Access control, AV, digital signage, POS, lighting, and building sensors increasingly run on network cable.
- Twisted pair Ethernet (Cat6 or Cat6A) handles most device connections, while fiber handles backbones and long runs.
- TIA guidance recommends Cat6A for Wi-Fi access points.
- Planning all systems together avoids duplicate cabling and future rework.
Frequently Asked Questions
What are network cables used for?
Network cables connect computers, printers, phones, Wi-Fi access points, cameras, and other devices to a network and the internet. Many also deliver power to those devices through Power over Ethernet.
Can network cables carry power?
Yes. Power over Ethernet sends low-voltage DC power over twisted pair cable along with data. Current standards support up to 90 watts at the power source.
What devices use Power over Ethernet?
Common PoE devices include VoIP phones, Wi-Fi access points, IP security cameras, access control readers, point-of-sale terminals, digital signage, and LED lighting.
Are network cables used for security cameras?
Yes. Most new security cameras are IP cameras that connect and receive power over Ethernet cable. Older analog cameras used coaxial cable.
Can network cables carry video to TVs and projectors?
Yes. HDBaseT and AV-over-IP systems send video, audio, and control signals over category cable, often up to 100 meters.
What network cable is best for most business uses?
Cat6 works well for standard computers and phones. Cat6A is recommended for Wi-Fi access points, high-power PoE devices, and new commercial construction.
What is fiber optic cable used for in a network?
Fiber is used for backbone links between network closets, floors, and buildings, and for long runs that exceed copper’s 100-meter limit.