The present invention relates to a communication translation system between hosts using different protocols across a network and methods thereof.

BACKGROUND OF INVENTION

Usage of Internet video conferencing and IP telephony has grown rapidly; as such there is an ever increasing importance for reliable interworking between protocols. Currently there are several different standards for signalling and control of multimedia communications. Some of the most widely used protocols are Real-time switching (RSW) control protocol and the IEFT Session initiation Protocol (SIP) where both protocols provide comparable functionality and quality of service by utilizing different mechanisms. Due to inherent differences between these protocols, establishing communication between them is not straightforward. As a result, users of one protocol cannot communicate with users of another. This poses a major setback since it is not feasible for all those who want to communicate via multimedia conferencing or IP telephony to operate across the same protocol.

There is therefore a need for a solution between different protocols which will enable interworking and ensure full end-end connectivity so that users with different client software can communicate. SUMMARY OF THE INVENTION

Accordingly there is provided a communication translation system between at least one RSW based client and at least one SIP endpoint (EP), the system includes a RSW based server, at least one RSW based client, at least one SIP EP, and a translation server which further includes a login admission control module, a registration module, a session initiation module, a module for forwarding media, a module for forwarding conference setup and a plurality of control messages wherein the at least one RSW based client, a RSW based server, at least one SIP EP and translation server are connectable in a network configuration.

There is also provided a method of communication translation between, at least one RSW based client and at least one SIP EP the method includes the steps of registering client and server information, acquiring server and users lists, RSW based client initiating a call setup by sending a CREATE message to the RSW based server, translating the call setup signalling, message, initiating a session, accepting the session, notifying a translation server and establishing a media connection.

There is further provided a method of communication translation between at least one RSW based client and at least one SIP EP, the method includes the steps of registering client and server information, SIP EP initiating a call by sending a CREATE message to the translation server, translating a session initiation message, initiating a session, accepting the session, notifying the at least one SIP and establishing a media connection. The present invention consists of several novel features and a combination of parts hereinafter fully described and illustrated in the accompanying description and drawings, it being understood that various changes in the details may be made without departing from the scope of this invention or sacrificing any of the advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, wherein:

Figure 1 illustrates an architectural model of the system of an embodiment of the present invention;

Figure 2 depicts a block diagram of the translation server of the embodiment of the present invention;

Figure 3 illustrates an example of a call session setup in the embodiment of the present invention;

Figure 4 illustrates a simulated example of a faulty call scenario in the embodiment of the present invention; and

Figure 5 illustrates a simulated output of the faulty scenario as illustrated in Figure 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a communication translation system between at least one RSW based client and at least one SIP EP and methods thereof. Hereinafter, this specification will describe the present invention according to the preferred embodiments of the present invention. However it is to be understood that limiting the description to the preferred embodiments of the invention is merely to facilitate discussion of the present invention and it is envisioned that those skilled in the art may devise various modifications and equivalents without departing from the scope of the appended claims. The following detailed descriptions of the preferred embodiments will now be described in accordance with the attached drawings either individually or in combination.

The present invention provides a communication translation system (100) between at least one RSW based client (101 ) and at least one SIP EP (103), wherein architecture of the system (100) is shown in Figure 1. The system (100) includes at least one RSW based client (101 ), a RSW based server (102),at least one SIP EP (103), and a translation server (104) which further includes further includes a login admission control module, a registration module, a session initiation module, a module for forwarding media, a module for forwarding conference setup and a plurality of control messages wherein the at least one RSW based client (101 ), a RSW based server (102), at least one SIP EP (103) and translation server (104) are connectable in a network configuration.

The system (100) can operate in two configurations; one configuration is without using a SIP server as seen in Figure 1 whilst the other configuration includes a SIP server. A. use case diagram can be found in Figure 2 which depicts the translation server (104) being integrated between RSW based clients (101 ) and SIP based clients, and also a plurality of modules included within the translation server (104).

The system (100) as seen in Figure 1 is a basic embodiment of the present invention and it is expected that there may also be, in other embodiments a plurality of RSW based clients and SIP EP's.

The RSW based server (102) provides RSW based clients (101 ) a platform to register/login to participate in conferences and also routes messages between the translation server (104) and RSW based client (101 ). Both the RSW based client (101 ) and SIP EP (103) are endpoints of the system (100) and provide a user interface for communication with other users of the system (100). The SIP based server provides SIP EP's (103) with a platform for registration to participate in conferences and also routes messages between the translation server (104) and SIP EP (103).

Architecture of the translation server (104) was designed using Specification and Description language (SDL), wherein the translation server (104) is a main processing centre for the system (100) where actual translation mechanism takes place. Figure 2 illustrates a block diagram of the translation server (104) as designed by SDL. The translation server (104) supports address resolution of both RSW based clients (101 ) and SIP EP (103). The translation server (104) bridges session descriptions between two signalling protocols to enable the two signalling protocols to communicate. In order to successfully establish a call between two endpoints, it is necessary to have a signalling destination address, media capabilities (local and remote) and transport addresses (local and remote). In RSW based clients (101 ) this information is spread over several messages at different stages of the call whilst in an SIP EP (103) this information is conveyed in a single INVITE message.

SIP is an application-layer control protocol which is designed to establish, modify and terminate communication sessions with one or more participants. When initiating a session, a SIP EP (103) sends out an INVITE message which contains all necessary information to establish and maintain a communication session. Therefore, it is the INVITE message which must be translated by the translation server (104) to enable the SIP EP (103) to communicate with the RSW based client (101 ).

By contrast, RSW control criterion creates a system for conducting and controlling conferences. When establishing a call, the RSW based client (101 ) spreads necessary information required to establish a call over several messages at different stages of the call. In this case the translation server (104) is therefore required to merge all messages at different stages of the RSW based client's (101 ) call into one single INVITE message, so that an SIP EP (103) can read the INVITE message.

Hence the translation server (104) operates by receiving a signalling message to initiate a call from, for example, the RSW based client (101 ). The translation server (104) then performs translation and sends a corresponding equivalent message to a call recipient, in this case, the SIP EP (103) and vice versa. The translation server (104) is able to maintain a conference message sequence on both sides in such a manner that neither the RSW based clients (101 ) nor SIP EP (103) are aware of the translation servers (104) presence and to both users it appears that they are communicating with a like entity.

A method of communication translation between at least one RSW based client (101 ) and at least one SIP EP (103) is also described. The method includes the steps of registering RSW based client (101 ) and translation server (104) with the RSW based server, whilst the SIP EP (103) registers with the translation server (104). The RSW based client (101 ) acquires a server and users' list from the RSW based server (102) so that the RSW based client (101 ) can access address information required to enable it to initiate a call session. RSW based client (101) initiates a call setup by sending out a CREATE message to the RSW based server (102) to establish a call between the RSW based client (101 )and at least one SIP EP (103). RSW based server (102) sends a NOTIFY message to the translation server (104). The translation server (104) translates a call setup signalling message and then initiates a session The SIP EP (103) responds by accepting the session and notifying the translation server (104). The translation server (104) negotiates a session description between RSW based server (102) and coordinates messages between RSW based client (101 ) and SIP EP (103) to establish a media connection between the RSW based client (101 ) and at least one SIP EP (103). At this point a media connection has been established between a RSW based client (101 ) and at least one SIP EP (103).

Where the call is to be terminated by a RSW based client (101 ), a TERMINATE message is sent to the RSW based server (102) which is routed to the translation server (104). The translation server (104) follows the termination procedure to release a call connection and then sends out an SIP BYE message to the SIP EP (103). The SIP EP (103) will then terminate the session and send out a response to the translation server (104). In the situation where the call is to be terminated by an SIP EP (103), a SIP BYE message is sent to the translation server (104) instead of a TERMINATE message. The translation server (104) will then send out a TERMINATE message which will be routed by the RSW based server (102) to the RSW based client (101 ). The RSW based client (101 ) will then follow necessary procedures to terminate the session.

There is further provided a method of communication translation between at least one RSW based client (101 ) and at least one SIP EP (103). The method includes the steps of registering the RSW based server (102) and SIP EP (103) with the translation server (104), whilst the RSW based client (101 ) registers with the RSW based server (102). An SIP EP (103) initiates a call setup by sending out an INVITE message to the translation server (104) to establish a call between SIP EP (103) and at least one RSW based client (101 ). The translation server (104) translates a session initiation message and initiates a session by sending out a NOTIFY message which is routed to the RSW based client (101 ). The RSW based client (101 ) accepts the session and sends out a response which is routed by the RSW based server (102) to the translation server (104).

The translation server (104) negotiates with the RSW based server (102) and coordinates messages between RSW based client (101 ) and SIP EP (103) to establish a media connection between the SIP (103) and at least one RSW based client (101 ). A media session has now been established between the SIP EP (103) and RSW based client (101 ) which can be terminated by either user via the method outlined above.

An example of the method is described further therein as seen in Figure 3. In this scenario, the call session is to be established by an SIP EP (103) (Ali) with an RSW based client (101 ) (Sara). This example does not use a SIP server wherein the method includes the steps as seen below:

1 . Ali sends out a REGISTER request to an SIP registrar within the translation server (104);

2. The translation server (104) adds a new record to a user table with Ali's information and then sends back a 200 OK response to Ali;

3. Sara also registers its presence with the RSW based server (102), by sending out a LOGIN message to the RSW based server (102);

4. The RSW based server (102) then sends out a LOGIN OK response to Sara's login request;

5. Ali sends out an INVITE request to the translation server (104);

6. When the translation server (104) receives the INVITE request, the translation server (104) will look through server tables to find Sara related information and then send out a NOTIFY message which is routed by the RSW based server (102) to Sara. At the same time the translation server (104) also sends out a 100 TRYING message;

7. Once Sarah receives a NOTIFY message, she sends out a JOIN message which is routed by the RSW based server (102) to the translation server (104);

8. The translation server (104) then sends out a 180 ringing response to Ali; 9. Simultaneously, Sarah's RSW based client (101 ) will send out a REQ-ACTIVE message which is routed from the RSW based server (102) to the translation server (104);

10. The translation server (104) receives the REQ-ACTIVE message it will then send a 200 OK response to the Ali, which indicates that Sarah has agreed to the call establishment;

1 1. Ali sends out an acknowledgement ACK message to the translation server (104), which then sends out a CONFJNFO message which is routed from the RSW based server (102) to Sara.

At this point a call session has successfully been initiated between Ali's SIP EP (103) and Sara's RSW based client (101 ).

In an alternative embodiment the system may include a SIP server; in this embodiment the methods will be as described above, however the SIP EP (103) and translation server (104) must register with the SIP server. The SIP server will perform address resolution and route all messages sent from the SIP EP (103) to the translation server (104).

ObjectGEODE was used to simulate the system and verify its functionality, simulation of various scenarios were performed an example of which is illustrated in Figure 4. A call mismatch sequence is shown in Figure 5 wherein the translation server (104) received a JOIN-OK message instead of a NOTIFY message. Thus, the translation server (104) subsequently drops the message and waits for a next message. This provides an example of a faulty recovery procedure that the translation server (104) uses to overcome any problems during call sessions between clients.

This invention is adapted for use in communication translation between hosts using different protocols across a network. However, the disclosed invention is suitable, but not restricted to, for use the above mentioned application.