Chapter 13: Telecommunications Traffic Engineering

The load carried on a telecommunication network is called traffic. Telecommunications traffic engineering, aka teletraffic engineering, is a set of techniques used to dynamically optimise the performance of the network through the prediction, analysis, and regulation of the behavior of the traffic transported by the network. A telecommunication network must support two types of traffic: signalling traffic and user traffic. Service providers raise revenue from user traffic and thus we refer to it as payload. Signalling traffic in data networks usually occurs in the form of packet header field. The header of IP packet in the Internet is akin to the in-band signalling in PSTN. We use traffic engineering to determine how much traffic a given telecommunication network can support at a given service quality and network performance. This chapter discusses the fundamentals of traffic engineering, and in particular, we study:

• PSTN as the origin of teletraffic engineering.

• Definition and calculation of basic teletraffic parameters, e.g. busy hour, grade of service, service levels, and traffic intensity.

• Importance of traffic modelling in traffic engineering, and study a sample of traffic models used in modern networks.

• Basics of queueing theory and its application in traffic engineering, and Kendall’s notation.

• Network dimensioning or capacity planning using Erlang-B and Erlang-C formulas.

• Technologies used to transport telecommunications traffic, including xDSL, SONET/SDH, DWDM, OTN, and T-SDN.