In a

Frame Relay Frame Relay is a standardized wide area network (WAN) technology that specifies the physical and data link layers of digital telecommunications channels using a packet switching methodology. Originally designed for transport across Integrated Se ...

network, committed information rate (CIR) is the

bandwidth Bandwidth commonly refers to: * Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range * Bandwidth (computing), the rate of data transfer, bit rate or thr ...

for a

virtual circuit A virtual circuit (VC) is a means of transporting data over a data network, based on packet switching and in which a connection is established within the network between two endpoints. The network, rather than having a fixed data rate reservation ...

guaranteed by an

internet service provider An Internet service provider (ISP) is an organization that provides services for accessing, using, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non-profit, or otherwise privat ...

to work under normal conditions. Committed data rate (CDR) is the payload portion of the CIR. At any given time, the available bandwidth ''should not'' fall below this committed figure. The bandwidth is usually expressed in

kilobits per second In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multi ...

(kbit/s). Above the CIR, an allowance of burstable bandwidth is often given, whose value can be expressed in terms of an additional rate, known as the

excess information rate Peak information rate (PIR) is a burstable billing, burstable rate set on routers and/or switches that allows throughput overhead. Related to committed information rate (CIR) which is a committed rate speed guaranteed/capped. For example, a CIR of ...

(EIR), or as its absolute value, peak information rate (PIR). The provider guarantees that the connection will always support the CIR rate, and sometimes the EIR rate provided that there is adequate bandwidth. The PIR, i.e. the CIR plus EIR, is either equal to or less than the speed of the access port into the network. Frame Relay carriers define and package CIRs differently, and CIRs are adjusted with experience.

Notes

References

Network performance Computer network analysis Temporal rates Frame Relay {{Compu-network-stub

See also

Notes

References