Alcatel

Alcatel Lucent

Nhut Quan Tran

Cao Thanh Phan

Jacques Litteaut

Karimkhan Remtoula

This invention relates to a method for setting up a conference call in a telecommunications network using the SIP protocol to set up a communication between a first terminal () and a second terminal (), call controllers () relaying signals for this communication. According to the invention, such a method is characterized in that it comprises the following steps:

Method for setting up a conference call in telecommunications network using the SIP protocol

In a method of routing calls to an external network from a calling node of a private network having a plurality of external network access circuit groups, each circuit group is connected to a gateway node of the private network. The method calculates a cost for different possible routes to the external network, the cost of a route to the external network being a function of the circuit group used and the route in the private network between the calling node and the gateway node of the circuit group used. It also chooses a route as a function of the calculated costs. The cost of a route to the external network is a decreasing function of the resources available on the circuit group used and is also a decreasing function of the load of the links used for routing in the private network. This optimizes use of the resources of the private network.

Routing calls to external networks from a private network

A multichannel dynamic telephone link provisionally sets up an internode medium connecting two nodes of a telephone network and including a plurality of channels each carrying a call between the two nodes. Time-delayed controllers associated with respective channels each assume a measurement state or an overshoot state or a latent state according to whether a call has been supported by the channel associated with the controller for a time less than an authorized duration or a call has been supported by the channel for a time at least equal to the authorized duration or no call has been supported by the channel, respectively. They clear down the internode medium when none of the time-delayed controllers is in its measurement state. One particular application is to private networks including a dynamic link via a public network.

Multichannel dynamic telephone link and method of operating it

The invention relates to a method of routing a call in a network having a plurality of nodes interconnected by trunks, the method including calculating the costs of different routes for taking the call, and selecting a route as a function of cost. According to the invention, the cost of a route is a function of the bandwidth available on the trunks making up the route, of the resources available on said trunks, and of the bandwidth required for the call. The cost of a trunk can be represented in the form of a vector whose first component is a decreasing function of the available bandwidth, and whose second component is a decreasing function of available resources. The invention makes it possible, when routing a call, to take account of quality of service in terms of bandwidth. If the second component is a function that has a value that is constant above some quantity of available resources, then the invention makes it possible to limit the number of routing calculations performed, and to avoid making new routing calculations so long as the topology of the network remains unchanged.

Routing calls in a telecommunications network on the basis of passband

In a method of routing a call in a network with a plurality of nodes connected by trunks, each call is assigned a priority level as a function of which it can pre-empt calls in the network. The cost of different routes for routing the call is calculated and one route is chosen as a function of the cost. The cost of a route is a function of the maximum value on the trunks constituting the route, the priority level of the calls pre-empted on each of the trunks, the number of calls pre-empted on the trunks and the resources available on the trunks. The priority level of existing calls can therefore be taken into account when routing a call. The single figure of the accompanying drawing shows the typical trend of the cost function of a trunk as a function of the available resources.

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Cergy, France

Nhut Quan Tran