PoE Standards

  Power over Ethernet (PoE) technology allows Ethernet cables to carry both data and electrical power to network devices over a single cable. This eliminates the need for separate power supplies and reduces cable clutter, making the installation of devices like IP cameras, wireless access points, and VoIP phones more efficient. Here’s a breakdown of how PoE technology works:   1. Basic Components of PoE Power Sourcing Equipment (PSE): This is the device that delivers power over the Ethernet cable. It could be a PoE-enabled switch, a PoE injector, or a router with PoE capabilities. The PSE determines how much power is needed and delivers it accordingly. Powered Device (PD): The device that receives both power and data from the Ethernet cable. Examples include IP cameras, wireless access points, VoIP phones, and other networked devices. The PD communicates with the PSE to receive the appropriate amount of power. Ethernet Cable: PoE typically uses standard Cat5e, Cat6, or higher Ethernet cables to transmit both power and data over the same cable. The cable is divided into pairs of wires, some of which are used for data transmission, while others are used for power delivery.     2. How Power is Delivered Over Ethernet PoE technology works by sending low-voltage DC power over the same twisted-pair cables used for data transmission. There are two main methods of delivering power: Spare-Pair Powering (Alternative B): In a standard Ethernet cable, only two of the four twisted pairs of wires are used for data transmission in 10BASE-T and 100BASE-T networks. The unused pairs (pins 4, 5, 7, and 8) can carry power without affecting data transmission. Phantom Powering (Alternative A): In 1000BASE-T (Gigabit Ethernet) and faster networks, all four wire pairs are used for data. In this method, the PSE superimposes the power on the data pairs (pins 1, 2, 3, and 6) without affecting the data signal. This is done by using the DC component of the signal for power delivery while the AC component handles data.     3. PoE Negotiation and Power Allocation The PSE and PD must communicate to ensure that the correct amount of power is delivered. This process is governed by the IEEE PoE standards: Detection: The PSE checks whether the connected device is PoE-compatible by applying a low voltage to the cable. If the PD has a signature resistance of about 25 kΩ, the PSE detects that it is PoE-capable. Classification: The PSE classifies the PD to determine its power requirements. PoE devices are divided into different power classes based on the amount of power they need, ranging from Class 0 (default) to Class 4 (high power). This allows the PSE to allocate the appropriate amount of power and optimize power distribution across multiple devices. Power Delivery: After classification, the PSE begins supplying power to the PD. The voltage is typically between 44 and 57 V DC, with the current varying based on the device's power needs. Monitoring: The PSE continues to monitor the power usage of the PD. If the device is disconnected, the PSE immediately stops providing power to avoid overloading the circuit.     4. PoE Standards PoE technology is standardized under the IEEE 802.3 family of protocols, with different versions specifying varying power levels: --- IEEE 802.3af (PoE): The original PoE standard provides up to 15.4 watts of power at the PSE and up to 12.95 watts at the PD, after accounting for power loss in the cable. This is suitable for low-power devices like VoIP phones and simple wireless access points. --- IEEE 802.3at (PoE+): An enhanced version of PoE that provides up to 30 watts at the PSE and up to 25.5 watts at the PD. This is used for more power-hungry devices, such as IP cameras and high-performance wireless access points. --- IEEE 802.3bt (PoE++ or 4-Pair PoE): The latest PoE standard, which supports higher power levels, offering up to 60 watts (Type 3) or 100 watts (Type 4) at the PSE. This is used for power-intensive devices such as PTZ (pan-tilt-zoom) cameras, LED lighting, and high-performance wireless devices.     5. PoE Advantages Simplified Installation: PoE allows devices to receive both power and data over a single cable, reducing the need for additional power outlets and streamlining installation. Cost Savings: By using PoE, businesses can save on installation costs, avoid the expense of running separate electrical wiring, and reduce the need for power adapters. Flexibility: PoE enables the deployment of devices in locations where power outlets may not be available or convenient, such as ceilings, walls, or outdoor locations. Centralized Power Management: PoE allows for centralized management of power, enabling network administrators to monitor and control the power supply to connected devices. This can improve energy efficiency and simplify troubleshooting.     6. PoE Limitations Power Budget: The total power available from a PoE switch is limited by its power budget. This means that only a certain number of devices can be powered simultaneously, depending on their power requirements. Cable Length: PoE is limited by the maximum Ethernet cable length, which is typically 100 meters (328 feet). BENCHU GROUP's long-distance transmission technology can transmit up to 250 meters without the relay devices. Beyond this distance, power delivery and data transmission become unreliable without using PoE extenders or repeaters.     Conclusion PoE technology is a powerful and flexible solution for powering network devices without the need for separate power supplies. By delivering power and data over a single Ethernet cable, PoE simplifies installation, reduces costs, and provides centralized power management. It's widely used in modern networking environments for devices like wireless access points, IP cameras, and VoIP phones.    

  Choosing the right Power over Ethernet (PoE) switch depends on several factors, including the type of devices you are powering, the size of your network, your power requirements, and future scalability. Here’s a guide to help you select the best PoE switch for your needs:   1. Determine the Devices You Need to Power Device Type: Identify which devices you will connect to the PoE switch. Common PoE-powered devices include IP cameras, wireless access points, VoIP phones, and IoT sensors. Power Requirements: Different devices have different power needs. For example, VoIP phones typically require less power (around 4-10W), while high-end IP cameras or wireless access points may need up to 30W or more. Ensure the switch can handle the power demand of all connected devices.     2. Understand PoE Standards and Power Output There are different PoE standards that define the amount of power a switch can provide to each connected device: --- IEEE 802.3af (PoE): Provides up to 15.4W per port, suitable for devices with lower power requirements, such as VoIP phones or basic IP cameras. --- IEEE 802.3at (PoE+): Delivers up to 30W per port, ideal for more power-hungry devices like advanced IP cameras or wireless access points. --- IEEE 802.3bt (PoE++): Provides up to 60W (Type 3) or 100W (Type 4) per port, supporting high-power devices like PTZ cameras, LED lighting, or digital signage. Tip: Make sure the switch’s PoE budget (total available power across all ports) is sufficient for the devices you plan to connect. For example, if you need to power ten devices that each require 15W, your switch must have a total PoE power budget of at least 150W.     3. Number of Ports --- Current Device Count: Count how many devices need to be connected to the switch. Ensure the switch has enough PoE-enabled ports to accommodate all of them. --- Future Expansion: Consider any future growth. If you plan to add more devices later, select a switch with additional ports or higher PoE capacity to avoid needing to upgrade prematurely. Tip: Switches are available with various port counts, commonly 8, 12, 24, or 48 ports. Choose a size that fits your current needs with some room for future expansion.     4. Total PoE Power Budget --- Power per Port: Calculate the total power each connected device will need and ensure the switch has a sufficient overall power budget. For example, if you connect ten PoE+ devices that require 25W each, your switch should have a power budget of at least 250W. --- Power Scaling: Some switches allow you to scale the power budget with additional power supplies. This can be useful if you need flexibility as your network grows. Tip: Ensure that the PoE switch provides a higher total power budget than your calculated needs to accommodate potential power surges or future high-powered devices.     5. Switch Management: Managed vs. Unmanaged --- Unmanaged Switch: Simple, plug-and-play devices. Ideal for small networks where no advanced features or network monitoring is required. --- Managed Switch: Provides control over network traffic, security, and configurations. Managed switches offer features like VLANs, Quality of Service (QoS), network monitoring, and troubleshooting. They are suitable for larger or more complex networks where control over data traffic and security is important. Tip: For business-critical applications, a managed switch offers greater flexibility, security, and control over your network.     6. Network Speed and Performance --- Gigabit Ethernet: For most modern networks, Gigabit Ethernet is standard, ensuring fast data transmission between devices. Ensure your switch supports 1 Gbps per port for seamless performance. --- 10 Gigabit Ethernet: If your network includes high-bandwidth applications like video surveillance or data centers, consider switches with 10 Gbps uplink ports for faster backbone connections. Tip: For most businesses, a Gigabit PoE switch will suffice, but 10 Gigabit uplinks are useful if you have large data or video traffic moving across the network.     7. Layer 2 vs. Layer 3 Switches --- Layer 2 Switch: A Layer 2 switch operates at the data link layer and is primarily used for forwarding traffic based on MAC addresses. Suitable for most small to medium networks. --- Layer 3 Switch: These switches offer routing capabilities, working at the network layer and allowing routing between different subnets or VLANs. This is useful for larger, more complex networks with multiple segments. Tip: If your network consists of multiple VLANs or subnets, a Layer 3 switch may provide better performance and traffic management.     8. PoE Power Scheduling and Management Features --- PoE Scheduling: Some switches allow you to schedule when to power PoE devices on or off, which can help save energy (for example, turning off VoIP phones after business hours). --- Power Management: Look for switches that offer power management capabilities, such as allocating power based on device priority or monitoring the power consumption of each device in real-time. Tip: If energy efficiency is a priority, opt for switches with advanced power management features.     9. Redundancy and Reliability --- Redundant Power Supplies: In mission-critical applications, consider switches that support redundant power supplies. This ensures the switch remains operational even if one power source fails. --- Environmental Conditions: If you are deploying switches in harsh or outdoor environments, look for ruggedized, industrial-grade switches that can withstand extreme temperatures, humidity, or vibrations. Tip: For critical environments like industrial applications or outdoor installations, select rugged switches with built-in power redundancy.     10. Additional Features --- VLAN Support: Virtual LANs (VLANs) allow you to segment your network into different groups, improving performance and security. This is particularly important in large or security-sensitive environments. --- Quality of Service (QoS): QoS prioritizes certain types of traffic, such as VoIP or video, ensuring that time-sensitive data gets through without delays. --- Link Aggregation: This feature allows multiple Ethernet links to be combined into a single logical link to increase bandwidth and provide redundancy. Tip: For advanced networks with IP cameras or VoIP, prioritize features like VLAN, QoS, and link aggregation.     11. Brand and Warranty --- Reputable Manufacturers: Stick to trusted brands such as Cisco, Huawei, Ubiquiti, H3C, Netgear, and Benchu Group. These manufacturers offer high-quality PoE switches with reliable support and updates. --- Warranty and Support: Check the warranty period and available support options, especially for mission-critical networks. Some brands offer extended warranties and responsive customer service. Tip: Investing in a reputable brand may cost more initially but can reduce the risk of network downtime and offer better long-term reliability.     Conclusion Choosing the right PoE switch for your business involves evaluating your current and future networking needs, including the types of devices you will power, total power budget, network size, and advanced features. Consider factors like network speed, scalability, and the manageability of the switch. For most businesses, a Gigabit managed PoE+ switch with room for expansion will be sufficient, but more advanced networks may require Layer 3 routing, 10 Gbps uplinks, or higher PoE budgets.    

  Power over Ethernet (PoE) standards define how power is delivered over Ethernet cables to power networked devices, such as IP cameras, VoIP phones, and wireless access points. The primary PoE standards are IEEE 802.3af, IEEE 802.3at, and IEEE 802.3bt. Each standard outlines the power levels, voltage, and maximum current that can be provided to devices. Here’s a breakdown of the different PoE standards:   1. IEEE 802.3af (PoE) Introduced: 2003 Power Output per Port: Up to 15.4W at the switch Available Power for Devices: Up to 12.95W (after accounting for power loss over the cable) Voltage: 44-57V Maximum Current: 350mA Cable Type: Requires Cat5 or higher (Cat5e, Cat6, etc.) Typical Devices Supported: --- VoIP phones --- Basic IP cameras (non-PTZ) --- Low-power wireless access points Overview: The IEEE 802.3af standard, commonly known as PoE, provides up to 15.4 watts of power per port. After considering power losses over the Ethernet cable, about 12.95W is available to power the device. This standard is sufficient for low-power devices such as VoIP phones and standard IP cameras but may not provide enough power for advanced devices with higher energy demands.     2. IEEE 802.3at (PoE+) Introduced: 2009 Power Output per Port: Up to 30W at the switch Available Power for Devices: Up to 25.5W Voltage: 50-57V Maximum Current: 600mA Cable Type: Requires Cat5 or higher Typical Devices Supported: --- Wireless access points with multiple antennas --- PTZ (Pan-Tilt-Zoom) IP cameras --- Advanced IP phones with video --- LED lighting Overview: IEEE 802.3at, known as PoE+, significantly increased the power delivery capabilities over PoE, providing up to 30W per port, with 25.5W available for devices. This higher power budget makes PoE+ suitable for more demanding devices, such as advanced IP cameras (PTZ cameras), wireless access points, and devices that support video functionality.     3. IEEE 802.3bt (PoE++ or 4-Pair PoE) Introduced: 2018 Power Output per Port (Type 3): Up to 60W at the switch Available Power for Devices (Type 3): Up to 51W Power Output per Port (Type 4): Up to 100W at the switch Available Power for Devices (Type 4): Up to 71.3W Voltage (Type 3): 50-57V Voltage (Type 4): 52-57V Maximum Current (Type 3): 600mA per pair Maximum Current (Type 4): 960mA per pair Cable Type: Requires Cat5e or higher for Type 3 and Cat6 or higher for Type 4 (for optimal performance) Typical Devices Supported: --- High-end wireless access points (Wi-Fi 6/6E) --- High-power PTZ cameras --- Digital signage --- Building automation systems (e.g., smart lighting, HVAC controls) --- Thin client workstations --- POS (Point of Sale) systems Overview: IEEE 802.3bt, also known as PoE++ or 4-Pair PoE, further expands the power capacity by using all four pairs of wires in an Ethernet cable to deliver power. This standard has two power levels: Type 3 (up to 60W) and Type 4 (up to 100W). PoE++ is designed to support high-power devices like large digital displays, high-performance wireless access points, and even IoT devices in smart buildings.     Summary of PoE Standards Standard Max Power Output per Port Max Power Available to Device Typical Devices Powered Year Introduced IEEE 802.3af 15.4W 12.95W VoIP phones, standard IP cameras, low-power access points 2003 IEEE 802.3at 30W 25.5W PTZ IP cameras, advanced access points, video phones 2009 IEEE 802.3bt (Type 3) 60W 51W High-end WAPs, PTZ cameras, building automation systems 2018 IEEE 802.3bt (Type 4) 100W 71.3W Digital signage, smart lighting, high-power PoE devices 2018     Choosing the Right PoE Standard for Your Network --- IEEE 802.3af (PoE): Ideal for networks with low-power devices such as VoIP phones, basic IP cameras, and simple access points. --- IEEE 802.3at (PoE+): Best suited for medium-power devices like PTZ cameras, advanced access points, and devices requiring more than 15.4W. --- IEEE 802.3bt (PoE++): Necessary for high-power devices such as Wi-Fi 6 access points, building automation systems, large LED lighting arrays, and other power-hungry equipment.   Make sure to assess the power needs of your connected devices and choose a PoE switch or injector that supports the appropriate standard. For future-proofing, opting for PoE+ or PoE++ switches ensures your network can handle more demanding devices as your infrastructure grows.

  Active PoE and Passive PoE are two methods of delivering power over Ethernet cables, but they differ significantly in terms of functionality, safety, and compatibility.   1. Active PoE Active PoE adheres to official standards, such as IEEE 802.3af, 802.3at (PoE+), and 802.3bt (PoE++). It involves intelligent communication between the power source (PoE switch or injector) and the powered device (e.g., IP camera or access point) to determine if the device is PoE-compatible and how much power is needed. Key Characteristics of Active PoE: --- Standards-Based: Follows IEEE standards (802.3af/at/bt). --- Power Negotiation: The PoE switch or injector communicates with the device to deliver the correct amount of power, preventing damage to non-PoE devices. --- Voltage: Commonly 44-57V for IEEE 802.3af/at and up to 57V for IEEE 802.3bt. --- Compatibility: Ensures safe operation with any IEEE-compliant PoE device, including backward compatibility with previous PoE versions. --- Safety: Built-in detection mechanisms to avoid delivering power to non-PoE devices, reducing the risk of over-voltage damage. Applications: --- Commonly used in enterprise-grade networks where safety, reliability, and standard compliance are critical. --- Powers devices like VoIP phones, IP cameras, wireless access points, and other networked devices.     2. Passive PoE Passive PoE does not follow any specific standard and does not include any form of power negotiation. It sends a fixed voltage over the Ethernet cable, regardless of whether the connected device is PoE-capable or not. Key Characteristics of Passive PoE: --- No Power Negotiation: Delivers power without checking whether the device is PoE-compatible. --- Fixed Voltage: Typically operates at a fixed voltage, usually 24V or 48V, depending on the system. --- Compatibility Issues: Requires devices to be specifically designed to work with the fixed voltage. Connecting a non-PoE device or a device with incompatible power requirements may result in damage. --- Less Safe: Since there is no detection mechanism, it is easier to damage non-PoE devices by accidentally supplying power to them. Applications: --- Often used in small or specialized networks, such as wireless ISP equipment or specific home networking setups, where cost is a factor, and power negotiation isn't needed. --- Powers devices like some proprietary wireless access points, cameras, and outdoor networking gear that is designed for Passive PoE.     Key Differences: Feature Active PoE Passive PoE Standards Follows IEEE standards (802.3af/at/bt) Non-standard (no IEEE compliance) Power Negotiation Yes, detects device compatibility No, fixed voltage sent directly Safety High, avoids powering non-PoE devices Lower, risk of damaging non-PoE devices Voltage 44-57V (standardized) Typically 24V or 48V (fixed) Applications Enterprise networks, VoIP, IP cameras Wireless ISP setups, specific devices Compatibility Compatible with any IEEE-compliant device Requires devices designed for fixed voltage     Which One to Choose? Active PoE is the better option for most scenarios, especially in enterprise networks, as it ensures compatibility, safety, and scalability. Passive PoE is more cost-effective but should only be used with devices specifically designed for it. It’s more common in niche applications or smaller network setups where cost is a priority, and users are aware of the risks.   If you are unsure about the device’s compatibility, Active PoE is the safer choice.    

  Choosing between PoE (Power over Ethernet) switches and non-PoE switches depends on your specific needs, budget, and the devices in your network. Here's a comparison of factors to help guide your decision:   1. Device Requirements PoE Switch: If your network includes devices that require power via Ethernet, such as IP cameras, VoIP phones, wireless access points (WAPs), or IoT devices, a PoE switch is necessary. It provides both data and power over a single Ethernet cable, simplifying installation and reducing cabling costs. Non-PoE Switch: If your network only consists of devices like computers, printers, or servers that don’t require power through Ethernet, a non-PoE switch is sufficient.     2. Budget Considerations PoE Switch: PoE switches generally cost more than non-PoE switches due to their additional power capabilities. However, the higher initial investment can be offset by reduced installation costs, as fewer power outlets and cables are needed. Non-PoE Switch: Non-PoE switches are more affordable and suitable for networks where devices are already powered through traditional means (e.g., wall outlets).     3. Ease of Installation and Flexibility PoE Switch: PoE switches simplify installation, particularly for devices in hard-to-reach locations where running electrical power would be difficult or expensive. They provide flexibility for expanding or moving devices without rewiring. Non-PoE Switch: Installation requires both Ethernet and power cables, which can complicate setup, especially in larger networks or buildings without sufficient power outlets.     4. Power Capacity (PoE Standards) --- PoE Switch: If you choose PoE, you’ll need to consider the PoE standards supported by the switch: --- PoE (IEEE 802.3af): Provides up to 15.4W per port, suitable for devices like VoIP phones or basic IP cameras. --- PoE+ (IEEE 802.3at): Provides up to 30W per port, ideal for more power-hungry devices such as pan-tilt-zoom cameras or wireless access points. --- PoE++ (IEEE 802.3bt): Supports up to 60W or 100W per port for even higher-powered devices like LED lighting or building automation systems. Non-PoE Switch: Power considerations are irrelevant here since the switch does not provide power to connected devices.     5. Network Scalability PoE Switch: Offers more scalability, as it allows you to add powered devices (IP cameras, WAPs) without needing additional power infrastructure. This is especially useful for growing businesses or future-proofing your network. Non-PoE Switch: Expansion may require significant changes to your power infrastructure if you later decide to integrate devices requiring PoE, such as security systems or IoT devices.     6. Environment and Use Case PoE Switch: Best suited for environments that require multiple PoE-enabled devices, such as: --- Surveillance systems with IP cameras. --- Office environments using VoIP phones and wireless access points. --- Smart buildings with IoT devices for lighting, HVAC, or security. Non-PoE Switch: Suitable for general networking in environments where devices already have separate power sources or for networks focusing on data-only connections, such as: --- Traditional office setups with computers and printers. --- Data centers with dedicated power solutions.     7. Power Backup and Management PoE Switch: Offers centralized power management and easier integration with uninterruptible power supplies (UPS), ensuring critical devices like IP cameras or VoIP phones remain powered during outages. Non-PoE Switch: Requires separate power solutions, making it more challenging to manage in the event of power failure.   Summary Table Factor PoE Switch Non-PoE Switch Device Types IP cameras, VoIP phones, WAPs, IoT Computers, printers, data-only devices Cost Higher initial cost More affordable Installation Easier, fewer cables, no need for power outlets Requires separate power and data cables Power Standards PoE (15.4W), PoE+ (30W), PoE++ (60-100W) No power delivery Scalability Flexible for future PoE devices Limited scalability without re-cabling Power Backup Centralized, easier UPS integration Requires separate UPS solutions     Final Decision --- Choose a PoE switch if you plan to power devices like IP cameras, WAPs, or VoIP phones directly through the network and want simplified cabling. --- Choose a non-PoE switch if your network consists of traditional devices that do not require PoE, or if cost is a primary concern and your use case does not involve PoE devices.   Considering your network's future growth and potential integration of PoE devices can also influence your decision.