Relating to data networks
Assignee1.Telia Research AB
InventorsNils Bjoerkman, Simon Andrew Crosby, Alexander Latour-Henner, Ian Malcolm Leslie, John Trevor Lewis, Fergal William Toomey, Raymond Philip Russell
Life of this patent
Estimating the term…
Abstract
A data network in which at least one switch is provided with the facility for estimating current network demands using a polygonal approximation to scaled cumulant generating function. The approximaton is iteratively refined in accordance with sampled data passing through the switch. The switch estimates the demand associated with a new data processing request as it is received by the switch and decides whether to accept the request based on available resources.
Claims56
A method of maintaining a target quality of service in a network switch behaving as a buffer of fixed size transmitting a multiplex of current connections at a constant service rate by controlling the admission of a connection requesting admission on the basis of a declared parameter comprising the steps of:
- recording the volume of traffic for each current connection over a block of time;
- estimating the scaled cumulant generating function (SCGF) λ(θ,s) for each connection;
- summing all the estimated SCGFs to obtain an aggregate SCGF;
- using the aggregate SCGF to obtain an estimated bandwidth requirement for the multiplex of current connections;
- providing a predicted SCGF for the connection requesting admission from the declared parameter;
- predicting the bandwidth requirement of the connection requesting admission from the predicted SCGF;
- summing the estimated and predicted bandwidth requirements;
- and
- accepting the connection requesting admission when the sum of the bandwidth requirements is less than the service rate of the switch.
A method as claimed in claim I in which the SCGF of each connection is calculated as:
- 15 λ ( θ , s ) = log 1 K ∑ k = 1 k = K ⅇ θ ( X k - sT k )
- where:
- λ(θ,s) is the SCGF,
- Xk is the volume of traffic recorded in the kth time block
- Tk is the duration of the kth time block
- and K is the number of time blocks in which the volume of traffic was recorded up to the current time.
A data network comprising:
- a network switch behaving as a buffer of fixed size when transmitting a multiplex of current connections at a constant service rate;
- a plurality of connectors feeding the switch;
- means for recording the volume of traffic of current connections for each current connector to the switch over a block of time;
- means for estimating the scaled cumulant generating function SCGF for each current connection recorded;
- means for summing the estimated SCGFs to obtain an aggregate SCGF;
- means for using the aggregate SCGF to obtain an estimated bandwidth requirement for the multiplex of current connections;
- means for presenting a new current connection requesting admission to the network by providing a declared parameter of the connection requesting admission;
- prediction means for providing a predicted SCGF for the new current connection requesting admission to the network from the declared parameter;
- means for predicting the bandwidth requirement of the connection requesting admission from the predicted SCGF;
- means for summing the estimated and predicted bandwidth requirements for the switch to produce a revised bandwidth requirement;
- and
- control means for deciding to admit the connection requesting admission on the basis of the revised bandwidth requirement for the switch.
A network management system for a multiplex of current connections providing a real time admission control over a connection requesting admission comprising:
- a network switch capable of transmitting signals at a constant service rate;
- means for providing a model of the switch in terms of a buffer of fixed size;
- a plurality of connectors feeding the switch;
- means for recording the volume of traffic of current connections for each current connector to the switch over a block of time;
- means for estimating the scaled cumulant generating function SCGF for each current connection recorded;
- means for summing the estimated SCGFs to obtain an aggregate SCGF;
- means for using the aggregate SCGF to obtain an estimated bandwidth requirement for the multiplex of current connections;
- means for presenting a new current connection requesting admission to the network by providing a declared parameter of the connection requesting admission;
- prediction means for providing a predicted SCGF for the new current connection requesting admission to the network from the declared parameter;
- means for predicting the bandwidth requirement of the connection requesting admission from the predicted SCGF;
- means for summing the estimated and predicted bandwidth requirements for the switch to produce a revised bandwidth requirement;
- and
- a control means for receiving the request of the new current connection requesting admission and the revised bandwidth requirement and for deciding to admit the connection requesting admission on the basis of the revised bandwidth requirement for the switch.
Dependencies are inferred from the claim text.