Editing Network throughput (section)

===Asymptotic throughput===
The '''asymptotic throughput''' (less formal '''asymptotic bandwidth''') for a packet-mode [[communication network]] is the value of the [[maximum throughput]] function, when the incoming network load approaches [[infinity]], either due to a [[Message passing|message size]],<ref>''Modeling Message Passing Overhead'' by C.Y Chou et al. in Advances in Grid and Pervasive Computing: First International Conference, GPC 2006 edited by Yeh-Ching Chung and José E. Moreira {{ISBN|3540338098}} pages 299-307</ref> or the number of data sources. As with other [[bit rate]]s and [[data bandwidth]]s, the asymptotic throughput is measured in [[bits per second]] {{nowrap|(bit/s)}} or (rarely) [[byte]]s per second {{nowrap|(B/s)}}, where {{nowrap|1 B/s}} is {{nowrap|8 bit/s}}. [[Decimal prefix]]es are used, meaning that {{nowrap|1 Mbit/s}} is {{nowrap|1000000 bit/s}}.

Asymptotic throughput is usually estimated by sending or [[network simulation|simulating]] a very large message (sequence of data packets) through the network, using a [[greedy source]] and no [[flow control (data)|flow control]] mechanism (i.e., [[User Datagram Protocol|UDP]] rather than [[Transmission Control Protocol|TCP]]), and measuring the volume of data received at the destination node. Traffic load between other sources may reduce this maximum network path throughput. Alternatively, a large number of sources and sinks may be modeled, with or without flow control, and the aggregate maximum network throughput measured (the sum of traffic reaching its destinations). In a network simulation model with infinitately large packet queues, the asymptotic throughput occurs when the [[Network latency|latency]] (the packet queuing time) goes to infinity, while if the packet queues are limited, or the network is a multi-drop network with many sources, and collisions may occur, the packet-dropping rate approaches 100%.

A well-known application of asymptotic throughput is in modeling [[point-to-point communication]] where [[Network latency|message latency]] <math>T(N)</math> is modeled as a function of message length <math>N</math> as <math>T(N) = (M + N)/A</math> where <math>A</math> is the asymptotic bandwidth and <math>M</math> is the half-peak length.<ref>''Recent Advances in Parallel Virtual Machine and Message Passing Interface'' by Jack Dongarra, Emilio Luque and Tomas Margalef 1999 {{ISBN|3540665498}} page 134</ref>

As well as its use in general network modeling, asymptotic throughput is used in modeling performance on [[massively parallel]] computer systems, where system operation is highly dependent on communication overhead, as well as processor performance.<ref>M. Resch et al. ''A comparison of MPI performance on different MPPs''in Recent Advances in Parallel Virtual Machine and Message Passing Interface, Lecture Notes in Computer Science, 1997, Volume 1332/1997, 25-32</ref> In these applications, asymptotic throughput is used modeling which includes the number of processors, so that both the latency and the asymptotic throughput are functions of the number of processors.<ref>''High-Performance Computing and Networking'' edited by Angelo Mañas, Bernardo Tafalla and Rou Rey Jay Pallones 1998 {{ISBN|3540644431}} page 935</ref>