the leaky bucket algorithm, described on the relevant Wikipedia page as the leaky bucket algorithm as a queue. This is a special case of the leaky bucket as a meter, which can be described by the conforming packets passing through the bucket. The leaky bucket as a queue is therefore applicable only to traffic shaping, and does not, in general, allow the output packet stream to be bursty, i.e. it is jitter free. It is therefore significantly different from the token bucket algorithm. These two versions of the leaky bucket algorithm have both been described in the literature under the same name. This has led to considerable confusion over the properties of that algorithm and its comparison with the token bucket algorithm. However, fundamentally, the two algorithms are the same, and will, if implemented correctly and given the same parameters, see exactly the same packets as conforming and nonconforming. Hierarchical token bucket The hierarchical token bucket (HTB) is a faster replacement for the class-based queueing (CBQ) queuing discipline in Linux. It is useful to limit a client's download/upload rate so that the limited client cannot saturate the total bandwidth. Conceptually, HTB is an arbitrary number of token buckets arranged in a hierarchy. The primary egress queuing discipline (qdisc) on any device is known as the root qdisc. The root qdisc will contain one class. This single HTB class will be set with two parameters, a rate and a ceil. These values should be the same for the top-level class, and will represent the total available bandwidth on the link. In HTB, rate means the guaranteed bandwidth available for a given class and ceil is short for ceiling, which indicates the maximum bandwidth that class is allowed to consume. Any bandwidth used between rate and ceil is borrowed from a parent class, hence the suggestion that rate and ceil be the same in the top-level class. Hierarchical Token Bucket implements a classful queuing mechanism for the Linux traffic control system, and provides rate and ceil to allow the user to control the absolute bandwidth to particular classes of traffic as well as indicate the ratio of distribution of bandwidth when extra bandwidth become available(up to ceil). When choosing the bandwidth for a top-level class, traffic shaping only helps at the bottleneck between the LAN and the Internet. Typically, this is the case in home and office network environments, where an entire