*The Laboratory for Research in Statistics and Probability
*

Carleton University - University of Ottawa,

*The Fields Institute for Research in Mathematical
Sciences *

and

*Present a Special Lecture *

*as part of the Fields Institute *

## Rate Control in Communication Networks

by Frank P. Kelly, *Cambridge University*

### Friday, November 6, 1998 NORTEL Networks, Carling Auditorium

### Abstract

This talk will discuss the stability and fairness of rate control algorithms
for communication networks. Algorithms that provide natural generalizations
to large-scale networks of simple additive increase/multi-plicative
decrease schemes are shown to be stable about a system optimum characterized
by a proportional fairness criterion. Stability is established by showing
that, with an appropriate formulation of an overall optimization problem,
the network's implicit objective function provides a Lyapunov function
for the dynamical system defined by the rate control algorithm. The
network's optimization problem may be cast in primal or dual form: this
leads to two classes of algorithm, which may be interpreted in terms
of either congestion indication feedback signals or explicit rates based
on shadow prices. Both classes of algorithm provide natural implementations
of proportionally fair pricing, and can be viewed as "charge-aware"
developments of, respectively, Jacobson's TCP algorithm and ATM available
bit rate algorithms.

As an application of the theory, the talk will conclude with a discussion
of ways in which the transmission control protocol of the Internet may
evolve to support heterogeneous applications. The claim will be made
that by appropriately marking packets at overloaded resources and by
charging a fixed small amount for each mark received, end-nodes are
provided with the necessary information and the correct incentive to
use the network efficiently.

This talk is based on joint work with Richard Gibbens, Aman Maulloo
and David Tan

### Background papers

1. "Rate control in communication networks: shadow prices, proportional
fairness and stability" (F.P. Kelly, A.K. Maulloo and D.K.H. Tan) Journal
of the Operational Research Society 49 (1998), 237-252.

http://www.statslab.cam.ac.uk/~frank/rate.html
2. "Resource pricing and the evolution of congestion control" (R.J.
Gibbens and F. P. Kelly).

http://www.statslab.cam.ac.uk/~frank/evol.html

### Location

NORTEL Networks

Main Auditorium

3500 Carling Avenue

(Main Lab #5 on Moody Drive just north of the Queensway)

### Transportation to NORTEL

A school bus has been hired to take participants from Carleton University
and the University of Ottawa to Nortel.

*Carleton University Pick-up*
| *Ottawa University Pick-up* |

Stacie Building (Chemistry)
| 585 King Edward (Mathematics Building) |

**Time of pick-up:** 8:10 a.m.
| **Time of Pick-up:** 8:25 a.m. |

(The bus will leave NORTEL around 12:15 p.m.) |