Hierarchical weighted fair queuing (HWFQ) is a packet scheduler that arranges queues in a tree and shares service among active sibling queues according to their weights at each level. A leaf queue’s current share depends on every branch between it and the root, so HWFQ can express nested policies—for example, allocating link capacity among customers and then dividing each customer’s allocation among its traffic classes.
How HWFQ allocates service
Picture a link at the root of a tree. Its child queues might represent departments, customers, or traffic classes; those branches can contain further queues, with individual flows at the leaves. At each interior node, the scheduler applies weighted fair queuing (WFQ) among that node’s active children. A configured weight is therefore local to its siblings, not necessarily a percentage of the entire link.
If child i has weight αᵢ and A is the set of active children at a node, the textbook share for active child j is:
βⱼ = αⱼ / Σ(i∈A) αᵢ
To find a leaf’s share of total service, multiply the active-share fractions along its path from the root. In the textbook’s illustrative example, a leaf under successive branches with shares of 70%, 40%, and 50% receives 70% × 40% × 50% = 14% of total bandwidth while those sibling shares apply. If the sibling corresponding to the 40% branch becomes inactive, that parent gives its full share to its active child; the leaf’s calculated share becomes 70% × 100% × 50% = 35%. These are example calculations, not measurements of a product or network deployment. The textbook’s HWFQ discussion describes the hierarchical allocation model.
Free tools Windows power users keep installed
One-click scans. No signup required.
#1 Best Overall
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
Why the hierarchy matters
Grouping changes the allocation policy. Suppose a parent divides service evenly between two branches. The first branch has two active leaves, and the second has one. Under the hierarchy, the first two leaves split their branch’s 50%, while the third receives the other 50%. A flat scheduler among all three leaves would instead give each about one-third. The difference is not a contradiction: “fair” depends on which queues are grouped together and where weights apply.
This makes HWFQ useful for expressing nested sharing policies, such as allocating a link among customers and then sharing each customer’s allocation among its traffic classes. To understand a policy, trace the tree from the link to the flow, and check the weights at every parent. When an inactive child stops competing for service, its active siblings can receive a larger fraction of that parent’s allocation.
Rank #2
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
What “fair” means in packet scheduling
Fair queuing is commonly described as an approximation of Generalized Processor Sharing (GPS), an idealized fluid model in which flows receive predictable service. A real link sends whole packets, not fluid, so a packet scheduler cannot reproduce the ideal allocation at time scales shorter than packet transmission. The calculated fractions describe target sharing under the model; actual service is packetized. RFC 7806 discusses fair queuing and the flow definitions used in network scheduling.
The meaning of a “flow” also depends on the implementation. A scheduler might classify traffic by a transport session, address pair or prefix, source, destination, or subscriber/customer/peer. Its accounting might count packets or account for their sizes. Packet counts may help prevent one stream from dominating another by sending more packets, but a bit-rate service objective must account for packet size. As a result, the label HWFQ alone does not establish that a particular subscriber or application is guaranteed a particular bandwidth; that depends on the classification and accounting rules.
Rank #3
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
HWFQ is not the same as priority or queue management
Priority settings
A priority setting and a weight-based fair scheduler are different policy choices. Priority determines which traffic is favored according to the configured priority rules; HWFQ shares service among active siblings according to weights at each node. Setting a priority for one IP address does not, by itself, show that the device uses HWFQ or reveal how other addresses share capacity. The scheduler’s classification and policy determine that.
Queue length and delay
HWFQ decides which queued packet or class receives service; it does not by itself limit total queue length or control queue delay. Active queue management (AQM) addresses queue sizes and is complementary to scheduling. IETF RFC 7567 explains this distinction and why scheduling alone should not be treated as a solution to bufferbloat.
Rank #4
- Dual Converters, Infinite Potential：Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
Related hierarchical mechanisms
Hierarchical Token Bucket (HTB) and Hierarchical Fair Service Curve (HFSC) are mechanisms used with hierarchical queues, while WFQ is a fair-queuing algorithm. These terms are related to hierarchical QoS, but they are not interchangeable names for HWFQ. Implementations can differ in how they define classes, interpret weights, redistribute unused capacity, enforce rate ceilings, and account for packets or bytes; the term HWFQ does not identify one universal configuration.
Quick Recap
Best Value
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Repair Windows errors before they cause bigger problemsFix Now →
