TCP Vegas is a
TCP congestion avoidance algorithm
Transmission Control Protocol (TCP) uses a congestion control algorithm that includes various aspects of an additive increase/multiplicative decrease (AIMD) scheme, along with other schemes including slow start and a congestion window (CWND) ...
that emphasizes
packet delay, rather than packet loss, as a signal to help determine the rate at which to send packets. It was developed at the
University of Arizona
The University of Arizona (Arizona, U of A, UArizona, or UA) is a Public university, public Land-grant university, land-grant research university in Tucson, Arizona, United States. Founded in 1885 by the 13th Arizona Territorial Legislature, it ...
by
Lawrence Brakmo and
Larry L. Peterson and introduced in 1994.
TCP Vegas detects congestion at an incipient stage based on increasing
Round-Trip Time
In telecommunications, round-trip delay (RTD) or round-trip time (RTT) is the amount of time it takes for a signal to be sent ''plus'' the amount of time it takes for acknowledgement of that signal having been received. This time delay includes p ...
(RTT) values of the packets in the connection unlike other flavors such as
Reno
Reno ( ) is a city in the northwest section of the U.S. state of Nevada, along the Nevada–California border. It is the county seat and most populous city of Washoe County, Nevada, Washoe County. Sitting in the High Eastern Sierra foothills, ...
,
New Reno, etc., which detect congestion only after it has actually happened via
packet loss
Packet loss occurs when one or more packets of data travelling across a computer network fail to reach their destination. Packet loss is either caused by errors in data transmission, typically across wireless networks, or network congestion.Ku ...
. The algorithm depends heavily on accurate calculation of the Base RTT value. If it is too small then throughput of the connection will be less than the bandwidth available while if the value is too large then it will overrun the connection.
A lot of research is going on regarding the
fairness provided by the linear increase/decrease mechanism for congestion control in Vegas. One interesting caveat is when Vegas is inter-operated with other versions like Reno. In this case, performance of Vegas degrades because Vegas reduces its sending rate before Reno, as it detects congestion early and hence gives greater bandwidth to co-existing TCP Reno flows.
TCP Vegas is one of several ''flavors'' of TCP congestion avoidance algorithms. It is one of a series of efforts at
TCP tuning
TCP tuning techniques adjust the network congestion avoidance parameters of Transmission Control Protocol (TCP) connections over high-bandwidth, high- latency networks. Well-tuned networks can perform up to 10 times faster in some cases. Howev ...
that adapt congestion control and system behaviors to new challenges faced by increases in available bandwidth in Internet components on networks like
Internet2
Internet2 is a not-for-profit United States computer network
A computer network is a collection of communicating computers and other devices, such as printers and smart phones. In order to communicate, the computers and devices must ...
.
TCP Vegas has been implemented in the
Linux kernel
The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the k ...
, in
FreeBSD
FreeBSD is a free-software Unix-like operating system descended from the Berkeley Software Distribution (BSD). The first version was released in 1993 developed from 386BSD, one of the first fully functional and free Unix clones on affordable ...
, in
Solaris
Solaris is the Latin word for sun.
It may refer to:
Arts and entertainment Literature, television and film
* ''Solaris'' (novel), a 1961 science fiction novel by Stanisław Lem
** ''Solaris'' (1968 film), directed by Boris Nirenburg
** ''Sol ...
.
- Oracle Solaris Administration: IP Services : Network Congestion and Congestion Control
/ref>
See also
*TCP congestion avoidance algorithm
Transmission Control Protocol (TCP) uses a congestion control algorithm that includes various aspects of an additive increase/multiplicative decrease (AIMD) scheme, along with other schemes including slow start and a congestion window (CWND) ...
* Development of TCP
References
External links
*University of Arizona
The University of Arizona (Arizona, U of A, UArizona, or UA) is a Public university, public Land-grant university, land-grant research university in Tucson, Arizona, United States. Founded in 1885 by the 13th Arizona Territorial Legislature, it ...
Advanced Protocol Desig
Vegas
{dl, date=April 2022
Vegas
Las Vegas, colloquially referred to as Vegas, is the most populous city in the U.S. state of Nevada and the county seat of Clark County. The Las Vegas Valley metropolitan area is the largest within the greater Mojave Desert, and second-larg ...