Multiplex communications – Pathfinding or routing – Combined circuit switching and packet switching
Reexamination Certificate
1999-09-20
2003-09-02
Ton, Dang (Department: 2661)
Multiplex communications
Pathfinding or routing
Combined circuit switching and packet switching
C370S465000, C370S466000, C370S467000, C370S353000
Reexamination Certificate
active
06614782
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, generally, to a communication system for switching data packets between connected communication terminals and, more specifically, to a communication system for switching data packets with allocated items of routing information between communication terminal apparatuses of the communication system and/or communication terminal apparatuses in a local network wherein the communication system includes at least one network coupling unit in the form of a subscriber terminal unit such that time-division-multiplex-oriented terminals which are also arranged in the communication system may be directly connected via the coupling unit.
2. Description of the Prior Art
In known communication systems, connections to a public or private communication network near the communication system are created through primary multiplex terminal units (also called S2 terminals) arranged in the system itself; a communication network taking the form for example, of an ISDN-oriented communication network. Via an S2 connection, a local network --(-- e.g., an Ethernet LAN that connects several personal computers --)-- can be connected with the ISDN-oriented communication network via a router. For this purpose, the router is equipped with both an S2 interface and a LAN interface in accordance with standards, wherein the S2 interface is connected with the output of the S2 terminal unit of the communication system and the LAN interface of the router is connected with the local network.
With respect to its essential function, a router is formed as layer
3
of the OSI reference model, wherein with the aid of router networks is connected physically with the respectively different topology of layers
1
and
2
--(-- e.g., Ethernet LAN and ISDN-oriented communication network. In order to switch data packets between the networks connected to the router, the address indications contained in the routing information of the data packets --(-- destination and source --)-- are interpreted by a control device arranged in the router wherein are evaluated, and the data packets are subsequently converted correspondingly.
The S2 interface has 30 useful channels that can be used only with larger local networks. This means that the S2 interface is not optimally utilized; i.e., the useful channels are physically assigned and cannot be used for other communication terminal apparatuses.
In U.S. Pat. No. 5,208,811, for example, a communication arrangement is described in which a plurality of LAN communication terminal apparatuses, arranged in a local communication network LAN, are connected via a separate network coupling unit (LAN/ISDN interworking unit) to an ISDN-oriented communication network with ISDN communication terminal apparatuses arranged therein. Given a connection setup, initiated by a LAN communication terminal apparatus, to an ISDN communication terminal apparatus, the network coupling unit transmits an ISDN channel number and an item of DLCI (Data Link Connection Identifier) information, representing an ISDN communication path, to the LAN communication terminal apparatus. This apparatus subsequently transmits a LAN data frame, containing an item of communication path information, to the network coupling unit. After reception of the LAN data frame, the network coupling unit carries out a format conversion in which the LAN data frame is converted into an ISDN data frame.
In addition, in U.S. Pat. No. 5,351,237 a communication arrangement is specified in which a multiplicity of local networks, LANs, are connected to an ISDN-oriented communication network via a multiplicity of network coupling units or, respectively, routers. Of the routers arranged in the communication arrangement, one is configured as a higher-order router (main router) and the remaining routers are configured as lower-order routers (sub-routers). Each router has a table in which items of router information are stored. Given an updating request initiated by a sub-router, items of router information updated by the main router are transmitted to the sub-routers in the form of data packets, wherein, using the received items of router information, each sub-router updates the items of router information stored in the tables.
The present invention, therefore, is based on the object of improving the coupling of communication systems, private branch exchanges, and local networks.
SUMMARY OF THE INVENTION
The essential aspect of the inventive communication system for switching data packets with allocated items of routing information between communication terminal apparatuses of the communication system and/or communication terminal apparatuses in a local network is that at least one network coupling unit in the form of a subscriber terminal unit, is arranged in the communication system. The communication system thereby includes a coupling field module that has a plurality of bidirectional terminals that operate according to a time-division-multiplex transmission method, and further includes a control unit that is connected with the coupling field module and has at least one signaling terminal. According to the present invention, the network coupling unit has at least one LAN terminal unit having a LAN interface for connection to a first local network, as well as at least one multiplex unit, which realizes a bidirectional output that operates according to a time-division multiplex transmission method, for connection to at least one of the bidirectional time-division-multiplex-oriented terminals of the coupling field module. In addition, in the network coupling unit there is arranged a signaling unit that includes a signaling output, for connection to the at least one signaling terminal of the control unit, and a conversion unit that is connected with each of the multiplex unit, the signaling unit and the LAN terminal unit. The conversion unit has means for the evaluation of the routing information, and means for switching the data packets from and to the local network or, respectively, from and to the coupling field module, depending on the result of the evaluation. The conversion unit also has means for the conversion, in accordance with a first transmission protocol, of items of signaling information into items of signaling information in accordance with at least one additional transmission protocol, and means for the adaptation of the data format of the data packets that are to be switched in accordance with either the first or the at least one additional transmission protocol.
The essential advantage of the inventive communication system is that through the construction of the network coupling unit as a subscriber terminal unit that can be integrated into the communication system, the time-division-multiplex-oriented terminals, arranged in the communication system, of the coupling field module are connected directly, via the network coupling unit or, respectively, via the conversion unit arranged therein, with the local network connected to the communication system. In this way, data packets that are transmitted to the communication system or, respectively, to the network coupling unit and that include an item of routing information can be switched between the networks connected to the communication system. Through the arrangement of router functions in the network coupling unit, it is possible to do without a financially costly connection of an external router (for example, an ISDN router or access server) including the S2 interface realized in the communication system. It is, thus, also possible to create an economical switching-oriented connection between a local network (for example, Ethernet LAN) and the communication network (for example, a private corporate network or a public ISDN-oriented network). The local network can, for example, be constructed as a communication system-internal administration network having a plurality of administration servers and maintenance servers connected thereto. An external administration central station, arranged in the public communi
Benning Gerhard
Fellerer Josef
Wehrend Klaus
Bell Boyd & Lloyd LLC
Ton Dang
Wilson Robert W.
LandOfFree
Communications system to transmitting data packets between... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Communications system to transmitting data packets between..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Communications system to transmitting data packets between... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3112923