Patent Application
20070140455
This application claims the benefit of Chinese Patent Application No. 200510132648.5, filed on Dec. 20, 2005. The disclosure of the above application is incorporated herein by reference.
The present disclosure relates to next generation network techniques, and more particularly to a media gateway applied in the next generation network.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
As current development of public switched telephone network (PSTN) and data network has been becoming stable and mature, people begin to give attention to the next generation network (NGN). The NGN is proposed with the evolution from bearing network to packet network, which adopts IP network as a bearing network. The key technology of NGN is soft switching, which may combine services, separate the access portion and the control portion of PSTN, and at the same time, provide interfaces for application and development, so that various flexible services may be developed to meet requirements of telecommunication market.
It is necessary that NGN should be subject to a gradually developing process from coexisting with PSTN to substituting for PSTN. During transition from PSTN to NGN, it is usually required for prior private branch exchange (PBX) devices of users access the NGN.
As shown in
However, the PBX at user side usually has dispersed sites, yet has small capacity. Typically, each site gives out one or two E1/T1 trunk uplink(s). In order to reduce the operating cost, operator usually may not desire to maintain an additional TDM (Time Division Multiplex) transport network, but E1/T1 line cannot be extended too long, therefore, PBX-AG only can be disposed at the place where the PBX at user side locates. As a result, the PBX-AGs are arranged dispersedly, and their capacity is small, yet the required number of PBX-AGs is large (each PBX-AG accesses a few PBXs, while cannot be integrated).
According to an aspect of the present invention, there is provided a media gateway including at least one remote module, each disposed in proximity to a private branch exchange (PBX) for converting format of a media stream and a signaling stream; and a central module, disposed in proximity to a packet switched network side and communicating with the at least one remote module for transporting the media stream and the signaling stream between each the at least one remote module and the packet switched network based on a control signaling from a media gateway controller (MGC).
In another aspect, the present invention provides a communication system including at least one private branch exchange (PBX); a media gateway controller (MGC); and a media gateway comprising at least one remote module, each disposed in proximity to one of the at least one PBX for converting format of a media stream and a signaling stream; and a central module disposed in proximity to a packet switched network and communicating with the at least one remote module for transporting the media stream and the signaling stream in IP format between the at least one remote module and the packet switched network based on a control signaling from the MGC, wherein the at least one PBX communicating with the packet switched network through the media gateway based on a control signaling from the MGC.
The present invention is applicable to PBXs that are disposed dispersedly and have a large accessing amount but small capacity. Especially, it is applicable to the case that there is no TDM connection between the central computer room and the location of the PBXs, while the PBX-AGs have to be disposed dispersedly.
According to the present invention, the central module integrates the remote modules together, and the MGC controls only one media gateway, thereby effectively decreasing the requirement for performance of MGC as compared to the case that each PBX requires one media gateway. Also, according to the present invention, the central module and the remote modules act as a single device, and maintainers may manage a single media gateway, which simplifies maintenance and management. Additionally, the present invention simplifies the function of the remote modules, which may lower the failure rate, and at the same time, simplify the failure recovery operation (by replacing the modules) to effectively reduce the cost of maintenance and management.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
The media channel is constituted by a timeslot for services over the TDM interface unit 213, a DSP (Digital Signal Processor) channel over the media-converting unit 212, and an IP endpoint (identified by an IP address and an IP port number) over the IP interface unit 214, and is automatically formed in certain rule after the remote modules are power-on. For example, a first timeslot, a first DSP channel, and a first IP port number over the IP interface form the first media channel, and so on. This is implemented by software encoding other than instructions from the central module. The central module may simply instruct to turn on or off the media channels through the gateway-control agent unit 217.
Likewise, after the remote modules are power-on, the signaling gateway unit 215 may also automatically generate a signaling channel. One end of the signaling channel is a TDM signaling link interface (such as PRI) for bearing 16 timeslots of DSS1 signaling, and the other end of the signaling channel is an IP signaling link (for example, IUA (ISDN Q.921-User Adaptation Layer) link for bearing DSS1 signaling). The signaling channel operates all the time.
The central module may make simple configuration for the parameters of the remote modules via maintenance-management agent unit 216, for example, configuration for the addresses of IP interfaces. The remote modules may report the status of media channels via maintenance-management agent unit 216.
The gateway-control unit 202 is controlled by a media gateway controller (MGC) 3 under gateway control protocol (such as H.248 protocol, Media Gateway Control Protocol (MGCP) and other private protocols). Specifically, the control command of MGC 3 should be mapped into on/off command for media channels of the remote modules. The IP interface unit at the remote module side 204 receives and transmits IP media stream from the remote modules. The IP interface unit at the network side 205 receives and transmits IP media stream from the network side. The IP forwarding unit 203 forwards media streams between the IP interface unit at the remote module side 204 and the IP interface unit at the network side 205, and at the same time converts IP addresses and port numbers. In fact, at the remote modules side, upon the remote modules and media channels thereon are determined, the home or peer IP address/IP port number are already determined. At the network side, the home IP address and port number are generally dynamically selected, while the peer IP address and port number need to be informed by the MGC 3. As a result, converting is often required, if necessary, it may convert encoding and decoding format or copy media streams (monitoring function) at the same time.
The signaling gateway aggregation unit 201 aggregates a plurality of signaling links of the remote modules into a single signaling link, and sends it to the MGC. In the opposite direction, it demultiplexes the signaling link into a plurality of signaling links and sends the signaling links to respective remote module.
The maintenance-management unit 206 is used to maintain and manage the entire media gateway, including maintaining and managing parameter configuration, maintenance and management operation, report of status of the apparatuses, and the like. The maintenance-management unit detects the status of the remote modules via Heartbeat Protocol (for example, BFD (Bi-direction Forwarding Detection) or other private heartbeat protocol) and if the status of the remote modules is normal, the remote modules are maintained and managed via maintenance-management unit 206.
In the media gateway of the present invention, the remote modules are simplified as much as possible to simply have minimal functions such as accessing PBXs and TDM-IP media conversion under control of the central module, while other functions are detracted which will be carried out by the central module. During operating process, the remote modules turn on and/or off the media channel, while the central module carries out the remaining processes.
When the remote module fails or requires maintenance, for example, the maintainer desires to check the current operating status of the apparatuses. As shown in
If there are plural remote modules, during maintenance the central module separately manages each remote module, and the managing manner is the same as shown in
In another aspect, the PBX at user side, the above-mentioned media gateway, and a media gateway controller may form an NGN communication system, in which the PBX accesses to the NGN via IP under control of the MGC through the media gateway.
Although illustrative embodiments have been described herein with reference to the accompanying drawings, it should be understood by those skilled in the art that the present invention is not limited to those preferred embodiments, and that various changes and modifications can be made therein without departing from the spirit and the scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200510132648.5 | Dec 2005 | CN | national |
