Method for, and a topology aware resource manager in an IP-telephony system

Abstract

A method and arrangement in a communications network. The object is to provide a way of handling recourse management issues and admission control within an IP telephony system. The object is achieved by a topology aware resource manager collecting routing information concerning the IP network, obtaining resource information concerning resources within the IP network, creating a resource map by combing the routing information and resource information, and performing recourse management issues and admission control within the system by the resource map and by interacting with a gatekeeper.

Description

[0001] The present invention relates to a method and arrangement in a communications network in accordance with the preambles of the independent claims. More specifically it relates to IP telephony recourse management issues and admission control within an IP telephony system. BACKGROUND OF THE INVENTION [0002] Telephony is one of the most important inventions in mankind. Since its birth Mar. 10, 1876, installing copper wires to each and everyone that needed communication capabilities has spread the technology worldwide. By coupling copper wires together between caller and called, a connection between these was achieved and they could eventually communicate with each other through their circuit. This kind of technology has become known as circuit-switched telephony. Anyone familiar with classical telephony know that there has been a great evolution within this circuit-switched telephony with, for instance, the AXE platform the Ericsson Corporation developed as their switching soluti...

AI Technical Summary

Benefits of technology

[0029] An advantage of the present invention is that increased utilisation of the network that will be achieved.

[0030] Another advantage of the present invention is that it is be possible to prioritise certain traffic and still allow other traffic in the same network. This gives flexible system solutions.

[0031] Another advantage of the present invention is that it makes it possible to reserve resources in advance to allow planned meetings and events.

[0032] Yet another advantage of the present invention is that it makes it possible to allow calls with predictable quality through non-H.323 domains if these domains where QoS enabled with inter-domain communicative resource managers. It would be In these inter-zones segments resources can be reserved in advance for traffic aggregates to avoid per call signalling in these segments, i.e. trunk bandwidth. This is a very resource efficient feature of the described technology. Reservations in advance are allowed to vary over time, e.g. reserve more bandwidth during working hours and less otherwise. In other words, the user of the described technology can schedule resources by predicting the resource need over time.

[0033] A further advantage of the present invention is the flexible interaction between service provider and end-user that a full resource map can provide if this is a customer need.

Problems solved by technology

Lack of topology awareness and path sensitive admission control is the most important drawback of current implementations of H.323 gatekeepers.

Between these geographically distributed routers R the bandwidth is limited.

This heuristic decision base will cause problems.

One user can, with or without malicious intentions, cause low overall utilisation and denial of service to other users.

Other problems will occur when the usage behaviour is changed in some way, or when there are topology changes.

Changed user behaviour could be that more users than usually gets their calls routed over a thin or loaded link, which could cause packet drops or increased delays.

Topology change could be caused by link failure.

Another problem is that gatekeeper-routed calls cannot be guaranteed high service quality in case direct calls are allowed.

If a gatekeeper Gk performs bandwidth management for gatekeeper-routed calls in a zone and is unaware of simultaneous direct calls, the total traffic volume may exceed available bandwidth at some link.

The problem here is that both gatekeeper-routed and direct calls use the same resources.

For ongoing calls, problems might occur if there are additional endpoints that want to join the session and these endpoints are located on networks segments without available resources or where the available resources are not sufficient to provide predictable service.

This issue will only occur when there is a multipart conference involving more than two endpoints.

Yet another problem is that different H.323 zones might be separated by non-H.323 enabled networks.

Currently there are no means to provide a predictable service in this case because resources are not controlled in a non-H.323 network.

However, QoS support using RSVP is not scalable, especially not when there are calls made between endpoints in different zones where there are a non-H.323 enabled network in between.

Current H.323 systems do not allow reservations in advance, which makes it hard to plan meetings with predicted quality.

Yet another problem in the H.323 standard is that a bandwidth request is always approved or rejected.

However, the document do not address how admission control can be done in speech transport systems, i.e. evaluating if there are sufficient capacity in the network before starting sessions and for communicating admission decisions to the system.

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