Traffic simulation algorithm for asynchronous transfer mode networks
AssigneeAvaya Technology Corp.
InventorRaife F. Smith, II
Life of this patent
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Abstract
The present invention is directed to a traffic simulation algorithm for an asynchronous transfer mode communications (ATM) network. The algorithm recognizes that packets in ATM networks can have interarrival times that are lognormally distributed or lognormally and normally distributed. Lognormal and, in some cases, normal random number generators are used to generate packet interarrival times of a synthetic traffic stream.
Claims37
In a packet-switched network, the network comprising at least one Asynchronous Transfer Mode or ATM switch and at least one ATM device other than the ATM switch, a method for analyzing the behavior of the network by performing steps comprising:
- (a) determining first and second proportions of a total number of packets transmitted and/or to be transmitted by the ATM network over a selected time interval, wherein the first proportion is associated with first packets of a first packet type and the second proportion is associated with second packets of a second packet type;
- (b) based on a first mean and variance, generating a first set of packet interarrival times representative of first packets, wherein each first packet has at least one of (i) a packet interarrival time less than a selected value, (ii) a packet payload of voice and/or video information, and (iii) at least a first admission priority, and wherein the distribution of the first set of packet interarrival times is at least substantially lognormal;
- (c) based on a second mean and variance, generating a second set of packet interarrival times representative of second packets, wherein each second packet has at least one of (i) a packet interarrival time of more than the selected value, (ii) a packet payload of information other than voice and/or video information, and (iii) less than the first admission priority and wherein the distribution of the second set of packet interarrival times is at least substantially normal;
- and
- (d) combining the first and second sets of packet interarrival times to provide a synthetic traffic stream, wherein a packet interarrival time is a time interval between the arrivals of temporally adjacent, individual packets.
In a packet-switched network, the network comprising at least one Asynchronous Transfer Mode or ATM switch and at least one ATM device other than the ATM switch, a system for characterizing packet interarrival times, comprising:
- (a) means for determining first and second proportions of a total number of packets transmitted and/or to be transmitted by the ATM network over a selected time interval, wherein the first proportion is associated with first packets of a first packet type and the second proportion is associated with second packets of a second packet type;
- (b) means for generating based on a first mean and variance, generating a first set of packet interarrival times representative of first packets, wherein each first packet has at least one of (i) a packet interarrival time less than a selected value, (ii) a packet payload of voice and/or video information, and (iii) at least a first admission priority, and wherein the distribution of the first set of packet interarrival times is at least substantially lognormal;
- (c) means for generating based on a second mean and variance, generating a second set of packet interarrival times representative of second packets, wherein each second packet has at least one of (i) a packet interarrival time of more than the selected value, (ii) a packet payload of information other than voice and/or video information, and (iii) less than the first admission priority and wherein the distribution of the second set of packet interarrival times is at least substantially normal;
- and
- (d) means for combining the first and second sets of packet interarrival times to provide a synthetic traffic stream, wherein a packet interarrival time is a time interval between the arrivals of temporally adjacent, individual packets.
In a packet-switched network, the network comprising at least one Asynchronous Transfer Mode or ATM switch and at least one ATM device other than the ATM switch, a system for characterizing packet interarrival times, comprising:
- a lognormal number generator operable, based on a first mean and variance, to generate a first set of packet interarrival times representative of first packets of a first packet type transmitted and/or to be transmitted over the network, wherein each first packet has at least one of (i) a packet interarrival time less than a selected value, (ii) a packet payload of voice and/or video information, and (iii) at least a first admission priority, and wherein the distribution of the first set of packet interarrival times is at least substantially lognormal;
- a normal number generator operable, based on a second mean and variance, to generate a second set of packet interarrival times representative of second packets of a second packet type transmitted and/or to be transmitted over the network, wherein each second packet has at least one of (i) a packet interarrival time of more than the selected value, (ii) a packet payload of information other than voice and/or video information, and (iii) less than the first admission priority and wherein the distribution of the second set of packet interarrival times is at least substantially normal;
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- a combiner operable to combine the first and second sets of packet interarrival times to provide a synthetic traffic stream, wherein a packet interarrival time is a time interval between the arrivals of temporally adjacent, individual packets.
Dependencies are inferred from the claim text.