Electrical computers and digital processing systems: multicomput – Computer-to-computer protocol implementing – Computer-to-computer data framing
Reexamination Certificate
1998-02-09
2001-10-23
Rinehart, Mark H. (Department: 2152)
Electrical computers and digital processing systems: multicomput
Computer-to-computer protocol implementing
Computer-to-computer data framing
C709S237000, C709S246000, C709S250000
Reexamination Certificate
active
06308217
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a signalling device, and more specifically to a device and method for connecting terminals having different versions of signalling protocol software installed.
DESCRIPTION TO THE RELATED ART
As one of communication systems, a system is known in which a user terminal conducts negotiations with a network for network resources (bands, quality, virtual channels, etc.) before it actually begins communications and then transfers information in accordance with the results of the negotiations. Such negotiations prior to communications is called signalling. The ATM system is typical of communication systems that perform such signalling.
FIG. 1
is a schematic diagram of an example of an ATM system. In this example, eight ATM terminals A to H are connected to an ATM network which has one or more ATM switches. The protocol implemented between each ATM terminal and the ATM network is defined by UNI (User-Network Interface), while the protocol implemented between ATM switches is defined by NNI (Network-Network Interface).
Each ATM terminal has a facility (software) of setting up a call by signalling and a facility of assembling and disassembling ATM cells. Hereinafter, software that implements the former facility is referred to as signalling software.
When a call is established over an ATM network, messages (SETUP, CONNECT, etc.) are transferred between an ATM terminal and the ATM network. In the ATM terminal, the signalling software processes these messages. The ATM network determines a path and communication capabilities in accordance with those messages and notifies the ATM terminal of them. The ATM terminal then makes communications over that path.
In general, software is often subject to revisions to make its improved versions. The above signalling software is not an exception, and at present its two versions (UNI 3.0 and UNI 3.0) are widely used for SVC (Switched Virtual Channel) services in the ATM system. The two versions of the signalling software are basically compatible with each other (interconnectable), but depending on some applications, they may not be connected together.
For example, a message used to make a request for call connection, “SETUP”, has a field in which AAL parameters are contained. The version UNI 3.0 is defined to set a specific value in “Mode” in the AAL parameter field, whereas the version UNI 3.1 has no “Mode” in the AAL parameter field. For LAN emulation which is an application for transferring LAN data over an ATM network, therefore, “Mode” is an essential parameter when the version UNI 3.0 is used, but it must not be present when the version UNI 3.1 is used. Suppose, for example, that a terminal B installed with the version UNI 3.0 of the signalling software and a terminal B installed with the version 3.1 attempt to communicate with each other based on LAN emulation. In this case, when a SETUP message (Mode has been contained) is transferred from the terminal B to the terminal C, the latter cannot recognize the Mode which is unnecessary for the version UNI 3.1. It may result in failure to process that message. That is, with such an application, it may become impossible to connect together terminals having the different versions of the signalling software installed.
FIG. 2
shows interconnectivity among the ATM terminals shown in FIG.
1
. Some NNI signalling protocols between the ATM switches, for example IISP version 1.0, can implement both UNI 3.0 and 3.1, however it is assumed that the NNI signalling protocol in this specification conforms to the version UNI 3.1.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a device and method which permits different versions of signalling software or terminals which have different versions of signalling software installed to be connected together reliably.
A signalling device of the present invention supposes an arrangement to implement signalling for establishing a connection between terminals that a network accommodates and has a storage section, a detector section, and a message translation section in addition to an existing signalling facility. The storage section stores identification information which identifies each of terminals that the network accommodates and version information representing a version of signalling software used by it with a correspondence established therebetween. The detector section, upon receipt of a signalling message, references the storage section to detect a version of the signalling software used by each of originating and terminating terminals of that signalling message. The message translation section translates the received message in accordance with the versions of the signalling software used at the originating and terminating terminals.
According to the above-described arrangement, terminals each of which uses a different version of signalling software can be connected together reliably.
Assuming that the originating and terminating terminals use first and second versions of signalling software, respectively, the message translation section deletes from the received message information elements which are contained in messages processed by the first version of the signalling software but not in messages processed by the second version. Alternatively, the message translation means adds to the received message predetermined patterns as information elements which are contained in messages processed by the second version of the signalling software but not in messages processed by the first version.
Another signalling device of the present invention supposes an arrangement that is connected to a switch installed inside a network to set up a call between terminals accommodated in the network. The storage section stores identification information that identifies each of lines that are accommodated in the switch and version information representing a version of the signalling software used by each line interface with a correspondence established therebetween. The detector section, upon receipt of a signalling message, references the storage section to detect the version of the signalling software used at the interface of each of the originating-side line and terminating-side line of the signalling message. The message translation section translates the received message in accordance with the versions of the signalling software used at the originating-side line and terminating-side line.
According to the above-described arrangement, a connection can be established reliably even if the versions of the signalling software used by the interface of the lines on which the connection is established are different to each other.
REFERENCES:
patent: 5740230 (1998-04-01), Vaudreuil
patent: 5862329 (1999-01-01), Aras et al.
patent: 5867653 (1999-02-01), Aras et al.
patent: 5920562 (1999-07-01), Christie et al.
patent: 5940393 (1999-08-01), Duree et al.
patent: 5943337 (1999-09-01), Sasagawa
patent: 5974237 (1999-10-01), Shurmer et al.
patent: 6058422 (2000-05-01), Ayanoglu et al.
patent: 6219348 (2001-04-01), Allen, Jr. et al.
patent: 715461 (1995-01-01), None
patent: 7-147580 (1995-01-01), None
patent: 7202906 (1995-08-01), None
Armitage, G., “RFC 2022—Support for Multicast over UNI 3.0/3.1 based ATM Networks”, Nov. 1996, www.faqs.org/rfcs2022.html, pp. 1-59.*
Armitage, G.J., “IP multicasting over ATM networks”, Apr. 1997, IEEE Journal on Selected Areas in Communications, vol. 15 Issue 3, pp. 445-457.*
McCutcheon, Mark, “UNI 3.0 and UNI 3.1”, Jul. 1997, www.cs.ub.ca
est/dsg/tevia_files/techreport
ode11.html, pp. 1.
Fujitsu Limited
Helfgott & Karas P.C.
Rinehart Mark H.
Romero Almari
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