In
packet switching networks, traffic flow, packet flow or ''network flow'' is a sequence of
packets from a source
computer
A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...
to a destination, which may be another host, a
multicast group, or a
broadcast
Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum ( radio waves), in a one-to-many model. Broadcasting began ...
domain. RFC 2722 defines traffic flow as "an artificial logical equivalent to a call or connection." RFC 3697 defines traffic flow as "a sequence of packets sent from a particular source to a particular unicast, anycast, or multicast destination that the source desires to label as a flow. A flow could consist of all packets in a specific transport connection or a media stream. However, a flow is not necessarily 1:1 mapped to a transport connection." Flow is also defined in RFC 3917 as "a set of IP packets passing an observation point in the network during a certain time interval."
Packet flow temporal efficiency can be affected by
one-way delay (OWD) that is described as a combination of the following components:
*
Processing delay (the time taken to process a packet in a network node)
*
Queuing delay (the time a packet waits in a queue until it can be transmitted)
*
Transmission delay (the amount of time necessary to push all the packet into the wire)
*
Propagation delay (amount of time it takes the signal’s header to travel from the sender to the receiver)
Utility for network administration
Packets from one flow need to be handled differently from others, by means of separate queues in
switches,
routers and
network adapters, to achieve
traffic shaping,
fair queueing or
quality of service. It is also a concept used in Queueing Network Analyzers (QNAs) or in packet tracing.
Applied to Internet
routers, a flow may be a host-to-host communication path, or a
socket-to-socket communication identified by a unique combination of source and destination addresses and port numbers, together with transport protocol (for example,
UDP or
TCP
TCP may refer to:
Science and technology
* Transformer coupled plasma
* Tool Center Point, see Robot end effector
Computing
* Transmission Control Protocol, a fundamental Internet standard
* Telephony control protocol, a Bluetooth communication s ...
). In the TCP case, a flow may be a
virtual circuit, also known as a
virtual connection or a
byte stream.
In packet switches, the flow may be identified by
IEEE 802.1Q Virtual LAN tagging in Ethernet networks, or by a
Label Switched Path in
MPLS tag switching.
Packet flow can be represented as a
path in a network to model network performance. For example, a water
flow network can be used to conceptualize packet flow. Channels can be thought of as pipes, with the pipe capacity corresponding to bandwidth and flows corresponding to data throughput. This visualization can help to understand bottlenecks, queuing, and the unique requirements of tailored systems.
See also
*
Argus – Audit Record Generation and Utilization System
*
Cisco NetFlow
*
Communication channel
*
Dataflow
In computing, dataflow is a broad concept, which has various meanings depending on the application and context. In the context of software architecture, data flow relates to stream processing or reactive programming.
Software architecture
Dataf ...
(software engineering)
*
Data stream
*
Flow control
*
Traffic shaping
*
Traffic policing (communications)
*
Flow network in graph theory
*
IP Flow Information Export
*
Path (graph theory)
*
Stream (computing)
*
Telecommunication circuit
*
Traffic generation model
References
{{reflist
Inter-process communication
Streaming
Packets (information technology)
Computer networking