Abstract:
The present invention provides a telecommunications packet switching system including a hardware portion and a software portion forming an advanced multiprocessing, multiprocessor system (including multiple processors, capable of running more than one process at a time). The hardware and software structures are fully distributed and fault-tolerant, providing a flexible configuration and remote management through the network itself, managing the switching and transmission of messages split into packets, including use of different specific protocols. The system can be connected to a variety of different networks, allowing a large concentration of low speed lines. A control station executes operational functions, and a terminal allows interaction with the system. A DC/DC converter is provided at each element in the processing unit.

Description:
This application is a continuation of U.S. patent application Ser. No. 07/788,147, filed Nov. 5, 1991, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to telecommunications. More specifically, the invention relates to telecommunications packet switching systems. 
     2. Related Art 
     Various packet switching systems are known in the art, which carry out switching of data packets between an origin and a destination. Disadvantageously, known packet switching systems do not incorporate different types of modems existing in the market, such as integrated (on-board) modems. Similarly, it is desirable that known electronic switching systems have larger packet switching capacity, and also data line connections with improved service quality. 
     Accordingly, there is a need to provide packet switching systems so that the cost of networks implemented with improved packet switching systems, and the cost of configuring each line, would be reduced. Also, an improved packet switching system would allow higher speed data interfaces to be included, the interfaces having the capacity to support a large variety of types of physical interfaces. Finally, it is envisioned that an improved system would have a definition and implementation of physical levels of data interfaces for connecting to digital transmission networks. 
     Despite these needs, existing telecommunications packet switching systems do not possess the desirable features pointed out above. 
     SUMMARY OF THE INVENTION 
     The telecommunications packet switching system according to the present invention is an efficient solution to the problem of increasing capacity over known telecommunications packet switching systems, providing both increased packet switching capacity and an increased number of line connections. It also improves service quality, cost operation of the data network, speed, definition of data interfaces, flexibility to adapt to different data networks, and implementation of new service and facilities. 
     The present invention provides a telecommunications packet switching system including a hardware portion and a software portion forming an advanced multiprocessing, multiprocessor system (including multiple processors, capable of running more than one process at a time). The hardware and software structures are fully distributed and fault-tolerant, providing a flexible configuration and remote management through the network itself, managing the switching and transmission of messages split into packets, including use of different specific protocols. The system can be connected to a variety of different networks, allowing a large concentration of low speed lines. A control station executes operational functions, and a terminal allows interaction with the system. A DC/DC converter is provided at each element in the processing unit. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is better understood by reading the following Detailed Description of the Preferred Embodiments with reference to the illustrative and non-limiting drawing figures, in which like reference numerals refer to like elements throughout, and in which: 
     FIG. 1 shows diagrammatically a view of how the present system may be connected with several types of existing networks. 
     FIG. 2 is a high level block diagram showing main portions of the system. 
     FIG. 3 shows a FIG. 2 network station 7 in greater detail. 
     FIG. 4 shows the FIG. 3 processing units 9, 10 in greater detail. 
     FIGS. 5, 6, and 7 show embodiments of the FIG. 3 connecting network in greater detail. 
     FIG. 8 shows the FIG. 3 processing units 9, 10 in greater detail. 
     FIG. 9 schematically illustrates the ratio between hardware and software. 
     FIG. 10 schematically illustrates high level software processing. 
     FIG. 11 schematically illustrates the structure of the operational software. 
     FIG. 12 schematically illustrates connection of the local and remote terminals to the network. 
     FIGS. 13-20 show structures and components of the system in greater detail than in previous drawings. In particular: 
     FIG. 13 illustrates a disk controller element (DCE). 
     FIG. 14 illustrates an interconnection network element (INE). 
     FIG. 15 illustrates a power supply and alarm element (PAE). 
     FIG. 16 illustrates a clock and alarm element (CAE). 
     FIG. 17 illustrates a line interface unit (LIFE). 
     FIG. 18 illustrates a supervision and control element (SCE). 
     FIG. 19 illustrates a primary digital link (PDL). 
     FIG. 20 illustrates a line interface element-integrated module (LIFE/IM). 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In describing preferred embodiments of the present invention illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. 
     The preferred telecommunications packet switching system is an advanced generation system, one with multiple processors, each capable of processing multiple tasks, with a fully distributed hardware and software structure. The telecommunications packet switching system is fault-tolerant, being flexibly configurable and remotely manageable through the network itself. 
     As can be seen in FIG. 1, the present system, designated by reference numeral 1, permits connection to various types of networks. For example, the present system 1 may be connected to a switched telephone network 4, either directly or through modems such as modem 5A. Likewise, the system 1 may be connected to an IBERMIC network 3, either directly or by means of high speed (up to 2 Mbps) or very high speed communication paths. Moreover, the system 1 may be connected to other packet switching networks 2, by dedicated lines or modems 5B. Also, the system&#39;s network station 7 (FIG. 2) allows direct connection with subscriber terminals 6 via dedicated lines and modems 5C. Finally, the present invention&#39;s flexible network station allows connection to other types of networks which may arise in the future. 
     Referring especially to FIG. 9, the preferred embodiment of the telecommunications packet switching system according to the present invention includes a hardware portion 15 and a software portion collectively indicated by reference numerals 16 and 17. 
     Referring more specifically to FIG. 2, the hardware portion 15 includes a network station 7 and a control station 8 connected to one or more operation terminals, one of which is shown schematically as element 6. The network station 7 carries out the packet switching function, allowing a large concentration of low speed lines (up to 9600 bps). 
     FIG. 3 shows the network station 7, including three components: processing units 9 and 10, a connecting unit 11, and a local interconnection highway 12. The preferred interconnection highway 12 is a serial bus including a clock distribution signal part, as well as data transmission parts for transmitting data between the processing units 9, 10 and the connecting unit 11. 
     As shown in FIGS. 4 and 7, the FIG. 3 processing units include a set of elements 13 which are interconnected to each other and to a network element 14 through the local interconnection highway 12. Communication among the different elements 13 of the processing units 9, 10, as well as communication between the elements 13 and those of other processing units, is provided by interconnection highway 
     The present telecommunications packet switching system provides three types of processing units 9, 10 differing from each other by the functions they perform. A first type of processing unit (designated 10 in FIG. 3) serves as a packet switching unit, serving external data lines. A second type of processing unit (designated 9 in FIG. 3) serves as a control and supervision unit, executing central control functions for the system, such as communication with the control station 8 (FIG. 2) for various operational functions. A third type of processing unit serves as a switching and control unit, executing packet switching and central control functions for the system. The processing units serve to reduce the number of lines required by the system. 
     As shown in FIGS. 5, 6, and 8, the connecting network may include any number of network elements 14, all being interconnected through local interconnection highways 12. They may be connected either directly or through other network elements, forming a flat array, facilitating expansion of the network and providing alternate paths between the network elements. 
     The control station 8 (FIG. 2) includes one or more computers, based on required capacity, necessary peripherals (such as console or data storage devices), guaranteeing software portability. The control station 8 performs the operational functions, the control station 8 performing control and processing of information related to management and maintenance of the system 1 (FIG. 1) as a whole. 
     The operation terminals 6 (FIG. 2) are preferably computers having resident processing capacity, and include color screens enabling graphic visualization of system operation, and other peripherals such as a mouse, all for making the system run more efficiently. The operation terminals 6 may be either local or remote to the control station 8, via the network station 7. 
     System software implements the functions of basic software (indicated by reference numeral 16, FIG. 9), applications software 17 (FIG. 9), and the operational software (FIG. 11). 
     The FIG. 9 basic software 16 provides the application software 17 with a virtual machine environment, isolating application software 17 from the hardware 15 as much as possible. In other words, from the point of view of the application software 17, the system 1 appears to be only a fault-tolerant processor with unlimited memory, unlimited processing capacity, and so forth. 
     The FIG. 9 application software 17 implements specific tasks of the functions of the system 1 as a whole. For example, application software 19 implements packet switching, communication protocols, other operational functions, and so forth. 
     The operational software shown schematically in FIG. 11 supervises and manages the overall system 1 and the networks related thereto, and performs several functions. The operational software provides communication between applications programs, independent of their relative physical location. It also measures communications traffic and monitors service quality. It manages data of the operation network. It establishes and releases virtual &#34;circuits&#34; in the virtual machine. It establishes and releases services for communicating between resident applications of different equipment in the system. It transforms data so that functions performed in different equipment may be performed independently. 
     Speaking in terms of logical abstraction, the system software includes resources grouped in layers, in which the operating capacity of the components of each layer is defined by its interface with the upper layer, through which it accedes to the resources that the lower layer elaborates and presents. The system software has two layers, a low level layer and a high level layer, as shown in FIG. 11. More generally, a &#34;layer&#34; may be defined as a group of separate code files of the same &#34;level&#34; as understood in the art of &#34;top-bottom&#34; software design. 
     The low level software elaborates the services (resources) used by the high level software, using the physical resources offered by the hardware shown in FIG. 2. At the same time, the low level software offers the high level software the services of communicating between high level components, providing access to processors for executing high level programs, and providing access to peripheral devices. 
     As shown in FIG. 10, the high level software is implemented as only one type of component, and includes processes 18, 19, 20, 21, each of which is an elementary unit of implementation. The creation of processes 20 and 21 is dynamic in nature, the processes 20 and 21 being created when needed and destroyed when they are no longer necessary. Communication between processes is executed by means of messages which allow exchange of data independent of the processor in which the data are executed. Some of these messages involve creation of processes, while others (23) involve interaction messages between processes. 
     The operational software is developed on the concept of a &#34;functional unit&#34;, each functional unit being a software entity that, in its entirety, provides all the functionality of the system shown in FIG. 11. Each functional unit has a specific task that sometimes coincides with a system function and other times group as more that one function. This breakdown into functional units allows independent functions to have little coupling to each other, in either their implementation or their operation, thus offering advantages of flexibility, uniformity in applied design methodology throughout the system, and software implementation. 
     As shown in FIG. 11, each functional unit has a basic service module 25 which includes a set of facilities and services 26 which are common to all of them. The functional unit also has a functional unit core 24 which is different in each case, providing the functional unit with it specific function. 
     FIG. 12 schematically illustrates connection of the local and remote terminals to the network. 
     FIGS. 13-20 show structures and components of the system in greater detail than in previous drawings. In particular: 
     FIG. 13 illustrates a disk controller element (DCE). 
     FIG. 14 illustrates an interconnection network element (INE). 
     FIG. 15 illustrates a power supply and alarm element (PAE). 
     FIG. 16 illustrates a clock and alarm element (CAE). 
     FIG. 17 illustrates a line interface unit (LIFE). 
     FIG. 18 illustrates a supervision and control element (SCE). 
     FIG. 19 illustrates a primary digital link (PDL). 
     FIG. 20 illustrates a line interface element-integrated module (LIFE/IM). 
     More specificially, FIG. 14 represents the interconnection network element 14 in FIGS. 4, 5, 6, 7 and 8. FIGS. 13, 15, 16, 17, 18, 19 and 20 represent different types of the block number 13 in FIGS. 4, 6, 7 and 8. The number of each of these types of blocks that make up the block 10 in FIG. 6 depend on the functions to be performed by block 10 
     The abbreviations in FIGS. 12-20 represent the following: 
     
         ______________________________________Abbreviation   Element______________________________________MAA            Rack Power Supply ModuleMAE            Element Power Supply ModuleMAI            Interface Adaptor ModuleMAR            RTC Access ModuleMBC            Packet Switching Bus ModuleMCA            Alarm Capture ModuleMCD            Disk Controller ModuleMCV            L I B (Local          Interconnection Bus)          Connection ModuleMEV            LIB Extension ModuleMMC            Switching Memory ModuleMMI            Integrated Modem ModuleMNE            Link Level ModuleMPO            Processing ModuleMRA            Alarm Collection ModuleMRC            Network Connection ModuleMTA            Alarm Transmission ModuleVIL            Local Interconnection BusIAB            Rack Power Supply InterfaceIAE            Element Power Supply          InterfaceIAV            LIB Access InterfaceIBC            Switching Bus InterfaceICA            Alarm Capture InterfaceICE            Power up Control InterfaceICM            Communications InterfaceICN            Console InterfaceIDI            Internal Data InterfaceIDE            External Data InterfaceIER            Network Elements InterfaceIEV            LIB Extension InterfaceIPA            Alarm Propagation InterfaceIRA            Alarm Collection InterfaceIRC            Interconnection Network          InterfaceITA            Alarm Transmission          InterfaceTCP/IP         Transmission Control          Protocol/Internet          Protocol______________________________________ 
    
     Modifications and variations of the above-described embodiments of the present invention are possible, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims and their equivalents, the invention may be practiced otherwise than as specifically described.