US 7466718 B2
A decoding device for analyzing communication protocols has a generic decoder into which at least one protocol description of a communication protocol is loaded, the at least one protocol description being capable of being interpreted by the generic decoder. The decoding device also has a specific decoder designed for a certain protocol description. The generic and specific decoders are reversibly connected.
1. A decoding device for analyzing communication protocols, the decoding device having an input for receiving coded data and an output for providing decoded data, comprising:
a generic decoder into which a limited number of protocol descriptions are loaded, the protocol descriptions being interpreted by the generic decoder during operation of the decoding device to decode the coded data at the input to the decoded data at the output; and
a specific decoder adapted to interpret a specific protocol, wherein an element function of the generic decoder is overlaid by a corresponding element function of the specific decoder so the corresponding element function is interpreted by the generic decoder.
2. The decoding device as recited in
3. A method of setting up a decoding device comprising the steps of:
providing a generic decoder into which a limited number of protocol descriptions are loaded, the protocol descriptions being interpreted by the generic decoder to decode coded data at an input into decoded data at an output;
providing a specific decoder adapted to interpret a specific protocol;
connecting the specific and generic decoders to form the decoding device; and
overlaying an element function of the generic decoder with a corresponding element function of the specific decoder so the corresponding element function is interpreted by the generic decoder.
4. The method as recited in
The present invention relates to protocol testers, and more particularly to a decoding device for analyzing communication protocols and to a method for setting up such a decoding device.
In communication technology communication between several participants takes place according to so-called communication protocols, i.e., sets of rules that are agreed upon for the communication which the communication facilities taking part in the communication must observe. For monitoring communication networks, and particularly for testing communication networks following the replacement of a communication instrument or the extension of the network by further communication instruments, tests to ensure the functioning of the communication network or to render support in trouble-shooting are carried out using protocol testers, especially before commissioning in order to avoid operational failures.
Such protocol testers require a decoding device that allows the protocol testers to apply the particular communication rules to the data picked up or received at a terminal unit so as to decode the data for further processing. Because of the frequently changing protocols to be analyzed, particularly with reference to the equipment and/or manufacturers of specific or proprietary protocols, such decoding devices have to be designed to be as flexible as possible, and thus usually are realized in software. Such decoding software is particularly flexible if it is generic, i.e., programmed to fit many protocols. The protocol descriptions required at any point in time with respect to a specific application are loaded into the generic decoding software. As shown in
The disadvantage of this generic decoding software approach is that the software is not as efficient as specific software adapted especially for the existing protocol. In particular the disadvantages relate to run times which impact realtime applications. This is because the loaded protocol descriptions have to be interpreted by the generic decoding software. Such generic decoding software has only a limited set of commands for the protocols to be loaded. When a new protocol description is loaded into the generic decoder, it may happen that the set of available commands does not allow the expression of certain rules of the new protocol description. This requires modification of the generic decoder, resulting in considerable maintenance and modification effort. This is due to the fact that the continual inclusion of new protocols makes the generic decode software become very complex, and extensions of the decoder software may result in parts that have previously functioned to suddenly not work anymore in the manner intended.
The alternative, as shown in
In other words a generic decoder into which protocol descriptions may be loaded may be likened to a processor which, while not being designed specifically for any particular application, processes everything, although slowly. Whereas a specific decoder may be likened to a processor that was designed for a specific application, i.e., the program to be executed is cast in concrete.
What is desired is a decoding device that works as fast as possible while being maintenance friendly and clearly laid out.
Accordingly the present invention provides a decoding device that has a generic decoder into which at least one protocol description of a communication protocol is loaded, the communication protocol being capable of being interpreted by the generic decoder, and a specific decoder designed for a certain protocol description. The generic decoder is limited to a certain size so as not to cause runtimes of an unwanted scale, and is supplemented by the specific decoder which is particularly suited to the protocol being analyzed at that point in time. The generic and specific decoders are reversibly connected to form the decoding device.
The objects, advantages and other novel features of the present invention are apparent from the following detailed description when read in conjunction with the appended claims and attached drawing.
Referring now to
The connection, or linking, of the generic decoder 16 with the specific decoder 18 is reversible, i.e., the individual components of the decoding device 14 may be maintained or updated separately without the need to generate the specific or generic decoders anew.
In the decoding device 14 shown in
Thus the present invention provides a decoding device that has a limited generic decoder and a specific decoder that are reversibly linked or connected so that each decoder may be maintained or updated separately.