Traffic flow (computer networking)

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In packet switching networks, traffic flow, packet flow or network flow is a sequence of packets from a source computer to a destination, which may be another host, a multicast group, or a broadcast domain. RFC 2722 defines traffic flow as "an artificial logical equivalent to a call or connection." [1] 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." [2] 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." [3] Packet flow temporal efficiency can be affected by one-way delay (OWD) that is described as a combination of the following components:

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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, policing, 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). 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. Communication 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

Related Research Articles

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<span class="mw-page-title-main">Transport layer</span> Layer in the OSI and TCP/IP models providing host-to-host communication services for applications

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<span class="mw-page-title-main">NetFlow</span> Communications protocol

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RDMA over Converged Ethernet (RoCE) or InfiniBand over Ethernet (IBoE) is a network protocol that allows remote direct memory access (RDMA) over an Ethernet network. It does this by encapsulating an InfiniBand (IB) transport packet over Ethernet. There are two RoCE versions, RoCE v1 and RoCE v2. RoCE v1 is an Ethernet link layer protocol and hence allows communication between any two hosts in the same Ethernet broadcast domain. RoCE v2 is an internet layer protocol which means that RoCE v2 packets can be routed. Although the RoCE protocol benefits from the characteristics of a converged Ethernet network, the protocol can also be used on a traditional or non-converged Ethernet network.

CoDel is an active queue management (AQM) algorithm in network routing, developed by Van Jacobson and Kathleen Nichols and published as RFC8289. It is designed to overcome bufferbloat in networking hardware, such as routers, by setting limits on the delay network packets experience as they pass through buffers in this equipment. CoDel aims to improve on the overall performance of the random early detection (RED) algorithm by addressing some of its fundamental misconceptions, as perceived by Jacobson, and by being easier to manage.

Multipath TCP (MPTCP) is an ongoing effort of the Internet Engineering Task Force's (IETF) Multipath TCP working group, that aims at allowing a Transmission Control Protocol (TCP) connection to use multiple paths to maximize throughput and increase redundancy.

Deterministic Networking (DetNet) is an effort by the IETF DetNet Working Group to study implementation of deterministic data paths for real-time applications with extremely low data loss rates, packet delay variation (jitter), and bounded latency, such as audio and video streaming, industrial automation, and vehicle control.

References

  1. ↑ N. Brownlee; C. Mills & G. Ruth (October 1999). "RFC 2722 - Traffic Flow Measurement: Architecture". IETF . Retrieved 2010-02-11.
  2. ↑ J. Rajahalme, A. Conta, B. Carpenter and S. Deering (March 2004). "RFC 3697 - IPv6 Flow Label Specification". IETF . Retrieved 2010-02-11.{{cite web}}: CS1 maint: multiple names: authors list (link)
  3. ↑ J. Quittek; JT. Zseby; B. Claise & S. Zander (October 2004). "RFC 3917 - IPFIX Requirements". IETF . Retrieved 2010-02-11.
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