This invention relates to method and device for controlling communication traffic, and particular to managing of communication traffic to networks, which will be occupied for a long time during the communication, such as communication between a telephone set and an internet or the like. It relates also managing of communication between telephone sets connected to the same access network (AN).
The European Telecommunications Standard Institute (ETSI) has produced standards of type V, the V5.1 and V5.2 interfaces (ETS 300 324-1 and ETS 300 347-1), as an interface between two systems, an Access Network (AN) and a Local Exchange (LE), with flexible (provisioned) information channel (bearer channel) allocation. Supported access types in the V5 interface standard are ISDN-BA and PSTN services. ISDN-BA are provided for digital communication and PSTN for speech communication.
An access network is a system which is implemented between the Local Exchange and the user. Several access networks can be connected to the same local Exchange.
An interface within ETSI has been defined to connect Access Networks (AN) to Local Exchanges (LE). Two V5 interfaces have been defined, one for multiplexing and the second for concentration capabilities in the AN controlled by the LE. This invention relates essentially to the V5.2 interface which concentrates the traffic and causes congestion for others when a sufficient number of users change the traffic behaviour from ordinary telephone calls to calls to be digitised and connected to an internet, a management network, an intranet or the like. This is also due for management networks.
The V5 interface standard, as defined in ETSI having the reference ETS 300 347-1 and ITU-T having the reference G.965, has no support for dropping traffic of the kind mentioned above already in the access network.
PCs (PC=Personal Computers) are nowadays often and will in the future automatically be provided with a multimedia interface, such an access to a data network, e.g. a public data network, for instance an internet, i.e. comprising multiple subnetworks communicating with each other. The PC is connected to the telephone net by means of a modem. Telephone communication between the PC and the public data network often takes a long time, which occupies a telephone line during a time essentially exceeding the time of a normal telephone call.
In an earlier system having direct access to a data network, each subscriber could be provided with a unit dividing the calls in telephone traffic and data traffic intended to be sent through different networks. The subscriber had then to have at least two subscriptions, one for the telephone network and one for the data network. A system like that need extra control circuits for the handling of data traffic on to the data network for each subscriber. This is expensive both for the communication company and for the subscriber.
EP-A-0731618 describes a method for controlling communication traffic for sets connected to the same access network, where every call is linked to a local exchange. A protocol is provided in the access network and the local exchange making it possible to connect sets connected to the access network to communicate with each other. The local exchange sends back an allocation signal according to the protocol when the local exchange has identified that a call request has its destiny to the access network which the call request come from, to set up the call inside the access network without having a pathsway set up for the call in question between the access network and the exchange during the communication.
It is important to provide a cheap and functional telecommunication network which always is available to transmit a call from a subscriber. Concentration of traffic is a common method used in transmission networks to reuse transmission lines for several subscribers. This method is well known and is build on Erlang""s model and very useful for ordinary analogue PSTN services (PSTN=Public, Switched Telephone Network). Nowadays, when the network has become overloaded with data service which has a different behaviour than ordinary telephone calls the existing traffic model need be justified. Data service behaviour can have quite short call length but generate more signalling than ordinary calls. Other data services like internet calls or the like have very long call lengths and no or very low signalling. This invention intends to provide a solution of the last-mentioned situation.
The invention provides a simple and inexpensive solution for minimizing the burden imposed on normal telephone traffic by the calls to data services. Data traffic across a telephone line connected to a local exchange in a telephone network will occupy this line for a considerable time period. The data traffic is, for instance, communication between a subscriber and the Internet or an intranet or the like. The invention separates this data traffic out from ordinary telephone traffic to thereby minimize the influence on ordinary telephone traffic.
An object of the invention is to provide a solution on the problem mentioned above.
To make it possible for ordinary telephone calls to be served in the same way as earlier the long time data traffic need be separated out from the V5.2 interface. Thus, the internet traffic should be routed from the calling station to a dedicated device, such as an access server, placed in or in the connection to the same access network as the calling station and connected almost directly to the long time network, such as internet or the like. The access server multiplexes the calls from the users of the access network before transmitting them to the long time network on only one line. Additional functionality could be made in the ordinary BCC protocol (BCC=Bearer Channel Connection) to allow internal call set-up in the access network controlled in the same way from the local exchange as ordinary calls. The intention according to the invention is that the access server should send a series of data packets for all the subscribers connected to the access network directly to the long time data network.
Thus, functionality already existing in the V5.2 interface standard is added to set-up internal connections in the access network to dedicated networks for internet kind of traffic or the like. The same access server could be used for a number of dedicated networks connected to a switch of for instance the ATM-kind connected to the dedicated networks, or an individual access server could be provided for each dedicated network or a mixture of these possibilities could be provided. The access server could be connected and treated by the access network in the same way as anyone of the telephone lines connected to it, i.e. it has the same type of protocol with L3-address etc.
When a subscriber makes a dial in order to connect to an internet or the like a connection is first made from the access network to a local exchange with a V5.2 interface. The BCC-protocol provided with an amendment makes it possible for the access network to provide internal connections between subscribers connected to the same access network. The local exchange identifies the call as a call to the data network and sends back an allocation to the calling set. The access network reacts on this allocation and makes a direct connection between the calling set and the access server. Thereafter the connection between the user and the data network is established without going through the local exchange and the V5.2 interface on bearer channels (B-channels) even though the local exchange still monitors the call through the C-channel for signalling. Thus, the public telephone network will not be loaded by the long time data traffic.
The invention add functionality already existing in the V5.2 interface standard to set-up internal connection in the access network to dedicated networks for data communication with for instance an internet. The invention will not interfere with the ordinary telephone traffic to subscribers outside the actual access network and/or data traffic of other kind than the one in the data network to which the access server(s) are directly connected to. The invention can act together with the AXE-system.