Обзор технологических и теоретических решений в области маршрутизации на основе качества обслуживания

Abstract

Проведено огляд рішень задач маршрутизації на основі якості обслуговування, що включає як протокольні варіанти, так і теоретичні рішення, які ще не отримали технологічної реалізації. Огляд охоплює комбінаторні методи маршрутизації, а також потокові моделі та методи формалізації та розв’язання маршрутних задач. Under rising requirements for telecommunication network role of routing increases, because routing is an effective tool to ensure the specified end-to end quality of service (QoS). Nowadays the routing is transformed into QoS-based routing which focuses on the searching one or more paths for delivering packets where all described in the SLA requirements for quality of service must be satisfied. A set of technological and theoretical solutions is developed for solving QoS-based routing problem. About it several concepts deserves attention among which source routing, precomputed routing, route server concept. From theoretical point of view QoS-based routing problem can be solved by using graph theory approach or flow-based mathematical model of network. The graph theory approach is based on structure only and doesn’t take into account flow properties of transmitted traffic. As a result it doesn’t allow allocating network resources between different traffics and concordance between routing, accesses, queuing, and reservation. As a rule a flow-based approach solves QoS-based routing problem as mathematical programming problem with QoS-constrains. For example, it can be tensor constrains. The article contains possible lines of development of QoS-based routing that include conversion to dynamical metrics and dynamical models with QoS-constrains, not only load balancing but quality balancing, concordance between routing and another traffic control tasks. Проведен обзор решений задач маршрутизации на основе качества обслуживания, включающий как протокольные варианты, так и теоретические решения, которые еще не получили технологической реализации. Обзор охватывает комбинаторные методы маршрутизации, а также потоковые модели и методы формализации и решения маршрутных задач.