KR20040066337A - Control point function destribution system on universal plug and play network - Google Patents

Abstract

PURPOSE: A CONTROL POINT FUNCTION DISTRIBUTION SYSTEM ON UNIVERSAL PLUG AND PLAY NETWORK is provided to perform easily an accessing process to a home network by adding a WAP gateway function to an outside of a home agent when a remote terminal has a WAP stack. CONSTITUTION: A control point function distribution system on universal plug and play network includes a home agent, a remote control point, and a WAP gateway. The home agent(310) is connected to a HTTP-based UPnP device by using a multicast method. The remote control point(320) is used for exchanging a multicast message of the home agent by using an UPnP stack and a WAP protocol. The WAP gateway(330) is located between the home agent and the remote control point in order to perform a converting process between a HTTP/TCP/IP protocol and a WSP*/WTP/WDP protocol, and UPnp is operated on TCP/IP as well as on a WAP stack.

Description

CONTROL POINT FUNCTION DESTRIBUTION SYSTEM ON UNIVERSAL PLUG AND PLAY NETWORK}

The present invention relates to a universal plug and play (hereinafter abbreviated as UPnP) network, and more particularly to a distributed control point function system.

UPnP is a home network industry standard that many companies have created by creating a forum (http://www.upnp.org).

The UPnP network consists of control points (CPs) that control devices and devices that provide services. The user may discover, describe, control, and monitor various devices through the CP.

On the other hand, as the popularization of mobile communication services is increasing the need for a home network remote access service that can control the equipment in the home and monitor the status through the mobile communication wireless terminal.

In the case of the UPnP home network, remote home access service using a wireless terminal is possible by distributing CP functions.

1 is a block diagram showing a configuration of a UPnP control point for the prior art. As shown in FIG. 1, UPnP in distributing a function of a UPnP control point to a home agent (HA) 110 and a remote control point 120 is shown. The home agent 110 includes some functions of the control point and communicates with UPnP devices in the home network 100 to process the UPnP protocol, and a remote control point provided in the remote terminal including some functions of the UPnP control point. 120 and a user interface unit 121 provided in a remote terminal to provide an interface to a user.

Referring to the operation of the prior art as follows.

In the UPnP protocol processing in the home agent 110 when the user is remote, some of device discovery and eventing use IP multicast, so it is preferable to process the service within the local home network.

In addition, user interface output must be made at the remote terminal.

Therefore, in order to enable this, the function of the control point is distributed, and UPnP function is properly distributed to the home agent (HA) 110 in the home network and the remote control point 120 outside the home network 100. One to one connection using a secure channel.

Therefore, as shown in FIG. 1, the function of the control point CP is distributed to the home agent HA 110 and the remote control point 120.

UPnP eventing uses both GE Unicast and IP Multicast in using GENA.

In case of eventing using IP unicast, the eventing message is received by the home agent in the middle without being sent directly to the remote control point, and the remote control point is obtained by polling the event message of the home agent. Can be configured to go.

This is useful when event messages occur frequently.

The UPnP protocol stack is defined in basic Internet protocols such as IP, UDP, TCP, and UPnP device architectures such as HTTP, HTTPU, HTTPMU, Simple Service Discovery Protocol (SSDP), GENA, and Simple Object Access Protocol (SOAP). It is composed of parts that are defined according to each equipment type and manufacturer.

Accordingly, the home agent (HA) 110 and the remote control point 120 may each receive basic services of UPnP devices through portions defined in the device architecture.

However, the UPnP service (UPnP API) defined in the UPnP device architecture is not sufficient to use functions specialized for each device and manufacturer.

Therefore, in configuring the control point (CP), by specifying a UPnP device, or a specific function as a UPnP vendor separately configured as a component to be installed and used whenever necessary.

This has the advantage of minimizing the storage space of the terminal while implementing control point functions optimized for each different device.

Figure 2 is an exemplary view showing a distributed structure of the UPnP control point when the remote terminal has a WAP stack 221 instead of the TCP / IP, HTTP stack.

The home agent 110 performs a function using some IP multicast of SSDP and GENA and a WAP gateway function 211 converting SOAP and GENA messages defined in the WML version into existing XML SOAP and GENA messages and loading them on HTTP. . The rest of the functions are performed by the remote control point 120.

In this case, since the remote terminal supports the same UPnP API as when the terminal has a TCP / IP and HTTP protocol stack, it is possible to share an application between the terminal and the WAP phone.

As described above, the operation process for the case where the remote terminal has the WAP stack is as follows.

First, the home agent 110 discovers devices in the home network through the UPnP device and UPnP search process and stores related information.

Then, when the remote control point 120 is connected to the home agent 110, the home agent 110 transmits the stored information to the remote control point 120.

Thereafter, the remote control point 120 requests the home agent 110 for a presentation page of a device to be controlled based on the device list received from the home agent 110.

In this case, the home agent 110 requests a presentation page from the device, receives an HTML page, converts it into a WML document, and transmits the converted HTML document to the remote control point 120.

When the remote control point 120 wants to receive an event message of the device, the remote control point 120 transmits an event subscription request to the home agent 110.

At this time, the home agent 110 transmits a UPnP event subscription request to the corresponding device and receives an event message transmitted by the device.

Then, the home agent 110 summarizes the received message and delivers it to the remote control point 120 at appropriate intervals.

In this case, when the remote control point 120 wants to control the device, a WML version of the SOAP message is configured and delivered to the home agent 110, and the home agent 110 converts the message into a SOAP message and requests the device. .

Accordingly, when the device sends a response message to the home agent 110, the home agent 110 converts the response message into a WML format and transmits the response message to the remote control point 120.

In addition, in the prior art, the case of distributing the functions of the remote UPnP control point as illustrated in FIG. 2 is described as an example. However, by distributing more functions among the home agent 110 and the remote control point 120, It can be configured in various forms. This means that it can be flexibly configured according to the function of the wireless terminal, user preferences, network conditions, and the like.

However, it is currently mentioned that in the distribution of UPnP functions between a home agent and a remote CP, it can be flexibly configured in various forms according to the function of the wireless terminal, the user's taste, the network state, etc. It is not defined how it is constructed.

Accordingly, the present invention is to distribute a plurality of UPnP functions to a remote control point mounted on a remote terminal to improve the conventional problem, by having a WAP gateway function outside the home agent when the remote terminal has a WAP stack It aims to provide a distributed control point function system on the UPnP network, which is designed to enable effective home network access from outside the home network.

That is, the present invention is to implement a remote control point by distributing a plurality of UPnP functions to a remote terminal having a WAP stack, to enable the exchange of UPnP messages in the public network outside the home network and also to the UPnP device and the public network on the home network By making it recognizable by the application in the remote control point, the remote mobile terminal can effectively access the home network.

1 is a block diagram of a control point in the prior art.

2 is a structural diagram of a protocol stack applied to FIG.

3 is an exemplary view showing a protocol relationship in an embodiment of the present invention.

4 is an exemplary view showing a correspondence relationship between an IP address and a port of a WAP gateway in an embodiment of the present invention.

5 is a block diagram of a control point function distribution system for an embodiment of the present invention.

6 is a flowchart of operation of a home agent in an embodiment of the present invention.

7 is an operational flowchart of a remote control point in an embodiment of the invention.

8 is an operation flowchart for packet conversion of a home agent in FIG.

FIG. 9 is a flowchart illustrating a connection process with a remote control point of a home agent in FIG. 6; FIG.

FIG. 10 is a flowchart illustrating a packet conversion process of a remote control point in FIG. 7; FIG.

FIG. 11 is a flowchart illustrating a process of processing a remote CP protocol in FIG. 7; FIG.

12 is a signal flow diagram illustrating an address translation process of a UPnP device in an embodiment of the present invention.

Figure 13 is a signal flow diagram illustrating the address translation of a remote control point in an embodiment of the present invention.

14 is a signal flow diagram illustrating a multicast message conversion procedure in a home agent in an embodiment of the present invention.

15 is a signal flow diagram illustrating a multicast message conversion process to a home agent in an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

310: Home Agent

311,321: Multicast / Unicast Converter

312: network address translator (NAT) 313,323: remote CP protocol processing unit

314,324: data storage 320: remote control point

322 media filter

1. In order to achieve the above object, a home agent and a remote terminal distribute UPnP functions in a public network so that UPnP messages can be exchanged in a public network, and a home communicates with a home-based HTTP-based UPnP device in a multicast manner. An agent, a WAP gateway that converts between the HTTP / TCP / IP protocol and the WSP * / WTP / WDP protocol, and a remote that exchanges multicast messages with the home agent through the WAP gateway by UPnP stack and WAP protocol processing A control point (CP) allows the UPnP protocol to operate on the WAP stack as well as the TCP / IP stack, so that the remote control point can access the home agent through the WAP gateway.

That is, in the present invention, the home agent and the WAP gateway are not provided with the UPnP stack, and the UPnP stack is provided only in the remote control point (CP), so that the UPnP stack operates in the WAP protocol stack and operates in the TCP / IP stack. And communicate with the UPnP device.

The WAP gateway may be configured to be located inside or outside the home agent.

If you configure the WAP gateway outside the home agent, the WAP gateway communicates with the home agent based on UPnP / GENA, SSDP, SOAP / HTTP / TCP, UDP / IP, and the remote control point and UPnP / GENA, SSDP, SOAP / HTTP / Communicates based on WSP * / WTP / WDP.

In other words, the core of the WAP protocol conversion in the present invention is to perform the conversion between the extended HTTP and WSP *.

Extended HTTP refers to the extension of message headers to accommodate SSDP, SOAP, and GENA over HTTP, as defined in UPnP Device Architecture 1.0. The WSP in the WAP protocol stack supports all of the basic HTTP headers, but not some of the headers used in UPnP.

Accordingly, the present invention proposes WSP * as an extended WSP protocol that supports some headers that WSP does not support. Hereinafter, the conversion between HTTP and WSP * is called WSP * conversion.

2. In the present invention, the WAP gateway is configured to perform message exchange with a remote control point using an IP address and a port number as well as protocol conversion from HTTP to WSP *.

Since the remote control point and the WAP gateway of the present invention use the WTP and WSP protocols based on the WDP protocol on the bearer network, the IP address / port number is not used.

However, in the context of extending the IP-based UPnP network environment to the public network, the WAP gateway has an IP address and port number representing each remote control point and converts it into a WSP / WDP address and port number of the remote control point. It is configured to perform NAT function.

3. The present invention is to configure the UPnP message exchange in the public network by distributing the UPnP function to the remote control point provided in the home agent and the remote terminal, the home agent is a dynamic UPnP device in the home via DHCP or AutoIP IP address and port pairs used by the device are converted to the external static IP and port pair of the home agent, and the network address that converts the external static IP and port of the remote control point to the dynamic IP and port number in the home. Network Address Translation (NAT), a Multicast / Unicast converter that converts multicast messages sent by the device into unicast messages, and forwards NAT table entries to the remote control point. CP protocol supporting message exchange for remote control point access and authentication And a remote CP access module comprising a call processing unit. The remote terminal includes a multicast / unicast converter for converting a multicast message transmitted to a home agent into a unicast message, and a UPnP for IP address and port number conversion. Message exchange in the public network with UPnP message filter for modifying messages and home agent access module consisting of a remote CP protocol processing unit for receiving NAT table entries from the home agent and exchanging messages for home agent access and authentication during initialization It is characterized by the configuration to enable this.

The network address translator performs a function of enabling a dynamic IP address in a home and a static IP address in a public network. The network address translator may be classified into a case belonging to a home agent and a case existing outside. That is, in the present invention, it is assumed that the network address translator belongs to a home agent, but the present invention can also be implemented in the case where the network address translator is external to the Internet, such as an IGD. In the present invention, NAT-related operations are replaced with UPnP action calls, not home agent internal function calls.

The multicast / unicast converter converts a multicast message into a unicast message in a public network section, and requires a NAT table entry for converting the multicast message. The NAT table entry is generated by a home agent collecting IP and port number pairs from a discovery message, a device description message, and a service description message.

Unicast messages converted from multicast messages are copied in the following cases and sent to the destination and require one-to-many NAT table entries rather than one-to-one.

One). A home agent sends a multicast message from a device in the home to multiple remote control points.

2). This is a case where there are a plurality of remote control points. In this case, a unicast message converted from a multicast message transmitted by an arbitrary remote control point is transmitted to a home agent as well as transmitted to a plurality of other remote control points. This is to create the same situation as when multiple control points are located in the home. For this purpose, the remote control point must know the presence of other remote control points. This can be accomplished by the home agent informing the existing remote control point of the identity of the remote control point registered in the initialization phase.

The home agent has a port for multicast for multicast transmission and reception, which consists of a fixed IP and a port number outside the home agent. Similarly, the remote control point has a port for multicast for multicast transmission and reception, which consists of a static IP and port number external to the remote control point. In UPnP, a fixed address example, '239.255.255.250:1900' is used as a multicast address.

In the present invention, in supporting the multi-home network and the remote control point, the multi-home network is composed of the external IP address of the UPnP device, and the multi-remote control point is made by NAT and unicast-multicast conversion.

In the present invention, the manner in which the remote control point accesses the multi-home network can be implemented without limitation. For example, UPnP devices distributed in different home networks can be shown to the user as if they were in one home network.

4. In the present invention, the message filter modifies UPnP messages including an XML description document including an IP address and a port number for IP address and port number translation, and may exist in a home agent, a WAP gateway, or a remote control point. have.

That is, although the present invention describes a case in which a message filter is provided in the remote control point under the assumption that the remote control point has more functions than the home agent, a technology that does not burden the home agent, for example, UPnP message full A message filter may be provided in the home agent or the WAP gateway to recognize and replace only the URL address in the message and not the parser. In this case, the NAT address notification for message filtering at the remote control point is not necessary.

5. In the present invention, the remote CP protocol is defined as a vendor specific protocol for implementing a remote control point, which is intended to support message exchange in a public network between a home agent and a remote control point.

The exchange message performs NAT table entry forwarding to the remote control point, remote control point access and authentication during initialization. In the present invention, it is assumed that the remote protocol message defines an header extended from HTTP, which basically uses a UPnP unicast port.

6. In the present invention, the WAP gateway may be configured to include a remote CP protocol processing unit as well as a message filter. This is because the message filter and the remote CP protocol processor can be shared by multiple remote control points and remote access service instances. In particular, this advantage may be prominent when the WAP gateway is present inside the operator's network.

Hereinafter, the present invention will be described in detail with reference to the drawings.

3 is an exemplary diagram showing a protocol relationship for an embodiment of the present invention, as shown here, the WAP protocol and the communication for the communication between the HTTP-based home agent 310 and UPnP and WAP-based remote control point 320 In adding the WAP gateway 330 supporting the HTTP protocol, the WAP gateway 330 is equipped with the WSP * protocol, which is an extension of the WSP supporting GENA, SSDP, and SOAP for the transparent operation of the UPnP protocol. Configure.

The home agent 310 is configured to perform multiple remote CP connection management, NAT, and unicast-multicast conversion functions.

The WAP gateway 330 is configured to perform a conversion function between the TCP / IP protocol and the WAP protocol.

The remote control point 320 is configured to perform a message filter, multicast / unicast conversion function.

In an embodiment of the present invention, the remote connection related information exchange between the home agent 310 and the remote control point 320 uses a remote CP protocol.

In addition, the WSP protocol may be recognized as an HTTP protocol for a wireless device. Unlike the HTTP protocol for sending characters, it is sent in a compressed binary format, but designed with web browsing in mind. Accordingly, WSP is a one-to-one correspondence with HTTP and includes conventional HTTP headers. However, HTTP used in UPnP supports extended headers corresponding to GENA, SSDP, and SOAP.

Therefore, in the embodiment of the present invention, the WSP * mounted on the WAP gateway 330 is configured exactly the same as the conventional WSP except that it supports GENA, SSDP, and SOAP for UPnP.

In addition, in order for the remote control point 320 to look like an IP-based control point in the home from the perspective of the UPnP device, in addition to the WSP * conversion, the WAP gateway 330 substitutes the remote control point 320 for the IP address and port number. Although necessary, the remote control point 320 and the WAP gateway 330 do not use an IP address / port number because they use the WTP and WSP protocols based on the WDP protocol on a bearer network.

Accordingly, the WAP gateway 330 has an IP address and a port number representing each remote control point, as shown in the example of FIG. 4 in the context of extending the IP-based UPnP network environment to the public network. Configure it to perform some sort of NAT function that translates it to the WSP / WDP address and port number of the remote control point.

In the embodiment of the present invention, in distributing functions equally to the home agent 310 and the remote control point 320 mounted on the remote terminal, the home agent 310 does not have a UPnP stack, but the remote control point 320 is provided. ) Has an UPnP stack operating in the WAP stack, and the operation of causing the WAP gateway 330 to perform TCP / IP protocol and WAP protocol conversion will be described.

The WAP gateway 330 may exist in the home agent 310 or the operator network or the public network.

In the embodiment of the present invention, it is assumed that the WAP gateway 330 is outside the home agent 310.

Control point function distribution system for an embodiment of the present invention, as shown in the configuration of Figure 5, to distribute the UPnP function to the home agent 310 and the remote control point 320 to enable UPnP message exchange in the public network In the configuration, the home agent 310 converts IP addresses and port pairs that are dynamically allocated by UPnP devices through DHCP or AutoIP in the home into external static IP and port pairs of the home agent. Network address translator (NAT) 312 that translates external static IP and ports of the remote control point into dynamic IP and port numbers in the home, and multicast that converts multicast messages transmitted by the device into unicast messages. A multicast / unicast converter 311, a data storage unit 314 for storing terminal information about the connected remote control point, and a NAT table. A remote CP access module comprising a remote CP protocol processing unit 313 for transferring an entry to a remote control point, accessing a remote control point in an initialization process, and exchanging messages for authentication, and the remote control point 320 A multicast / unicast converter 321 for converting a multicast message to a home agent into a unicast message, a UPnP message filter 322 for modifying UPnP messages for IP address and port number translation, and a home agent Data storage unit 324 for storing other remote control point information connected to the 310, information related to the message filter 322, information related to the home agent 310, and NAT table entries from the home agent 310. It consists of a remote CP protocol processing unit 323 that supports message exchange for home agent access and authentication during reception and initialization. It is configured by having a home agent connected to the module.

The network address translator 312 may be configured to be provided outside the home agent 310.

The message filter 322 may be provided in the WAP gateway 330.

UPnP devices are dynamically assigned IP addresses that are valid only inside the home using DHCP or AutoIP, and they need more port numbers for the web server along with those IP addresses. For example, if you add '239.255.255.250:1900' as a multicast destination, you can operate as a UPnP device. In this case, the control point 310 may add an IP address and a multicast receiving address (for example, '239.255.255.250:1900') for the web client.

The network address translator 312 converts the IP address and port number dynamically allocated to the UPnP device for the web server in the home into the external IP and the port number of the home agent 310, and the external IP of the remote control point 320. And port number are converted into the internal IP and port number of the home agent (310). In other words, it communicates using the internal IP address in the home and communicates using the external IP address in the public network.

As such, a network address translation (NAT) operation of changing an address field other than packet contents is performed only at the home agent 310 and not at the remote control point 320.

Thus, when a multicast message is sent over a public network to multiple remote control points, each connected remote control point is converted into a unicast message directed to the multicast external address / port of that remote control point.

In addition, the multicast message transmission from the remote control point 320 to the home agent 310 is addressed to a multicast port outside the home agent and transmitted in unicast form, and also transmitted to other remote control points in unicast form. And the remote control point 320 sends a multicast message to the home agent 310 and the home agent 320 delivers the multicast message to another remote control point.

Such a network address translator 312 may exist externally, such as an IGD.

On the other hand, if address and port information is included in the message content transmitted from the device to the control point (CP), they should be converted to an external address, and the message filter 322 plays a role.

The reason for having the message filter 322 in the remote control point 320 is that the home agent 310 does not include the UPnP stack. Therefore, you cannot see inside the UPnP message.

Remote control point 320, on the other hand, has an XML parser and a UPnP stack. These are essential when checking and modifying UPnP internal messages. Since the remote control point 320 does not have NAT information, the home agent 310 notifies the remote control point 320 whenever NAT information is generated, and the remote control point 320 reports the NAT information to the remote CP protocol data. It is stored in the storage unit 324 and managed.

That is, the message filter 322 may be referred to as a type of application level gateway (ALG) applied only to a specific application and may be provided to the home agent 310 by changing an installation location.

The operation and the effect of the embodiment of the present invention configured as described above will be described with reference to FIGS. 6 to 15.

1. Operation of the home agent 310 in the embodiment of the present invention will be described with reference to the operation flowchart of FIG.

First, boot the required components and check if there are any remote control points connected.

If there is an access control point, packet conversion is performed on the transmitted and received UPnP packets in the same process as the flowchart of FIG.

If there is no remote control point connected, check whether there is a connection request from the remote control point (320 in FIG. 3).

Accordingly, when the access request is confirmed from the remote control point 320, the access procedure is performed in the same process as the flowchart of FIG.

If the connection request is not confirmed from the remote control point, check whether there is a connection termination request from the currently connected remote control point.

Accordingly, when the connection termination request is confirmed, the connection termination procedure is performed. This process includes the return of the necessary system resources as part of the termination of the home agent service and the termination notification using the remote CP protocol. Normally, the remote control point closes the connection but can continue to run for another session with the same home agent or for a session with another home agent, depending on the conditions.

If the connection request or the connection termination request is not confirmed from the remote control point, check whether there is a connection termination request from the home agent.

Accordingly, the operation is terminated when it is determined that the home agent is requested to terminate the access. On the contrary, if the home agent is not confirmed, the above steps are repeatedly performed.

In the operation process of FIG. 6, the access and termination process may be performed by allocating / returning an IP address / port on behalf of the remote control point 320 in the WAP gateway 330 and assigning / returning a structure for mapping to the WDP address / port number. It includes.

In addition, the packet conversion process in FIG. 6 will be described with reference to the operation flowchart of FIG. 8. That is, FIG. 8 illustrates a packet conversion process performed in the remote CP access module in the home agent 310.

Check whether there is a UPnP packet transmitted from the remote control point 320.

At this time, if there is a packet received from the remote control point 320 over the public network, it is checked whether the receiving device address exists in the NAT table.

If the address of the receiving device does not exist in the NAT table, it means that the device is not registered. Therefore, the receiving device address is determined to be an error and the remote control point 320 is notified of the content.

On the contrary, if the receiving device address exists in the NAT table, the receiving address field is converted using the NAT table and transmitted to the corresponding device or multicasted.

In this case, as shown in the example of FIG. 15, the multicast packet should be transmitted from the remote control point 320 to the multicast port of the home agent 310 using a unicast packet and its NAT entry is remotely controlled. Allocated at point connection.

In addition, if there is a packet transmitted from the device to the remote control point 320, the transmission device address is checked in the NAT table.

If the source device address does not exist in the NAT table, the device allocates a NAT table entry first. That is, when there is a transmission packet from the UPnP device, as shown in the example of FIG. 12, entry allocation includes allocation of an external IP address and an external port of the home agent 310. In this way, the contents of the assigned entry are notified to all connected remote control points. If the message filter is provided in the home agent 310, notification of entry contents is omitted.

Thereafter, the transmission packet in the device is transmitted to the public network after the transmission device address is converted into an external address.

At this time, when the transmission packet is multicast, as shown in the example of FIG. 14, the transmission packet is transmitted in unicast form to the multicast port of the connected remote CP. That is, in the case of multicast packets, the sender device address is converted by referring to the NAT table, the NAT table is read from the corresponding external multicast address list, and the packet is copied for each external multicast address and transmitted.

In practice, the address translation of unicast and multicast need not be distinguished as shown in the operation flowchart of FIG.

Although the multicast packet and the unicast packet are classified based on the port, the multicast packet may be distinguished by adding additional information to the packet header.

In FIG. 6, the connection process of the home agent 310 with respect to the connection request from the remote control point 320 will be described with reference to the operation flowchart of FIG. 9.

In the process of FIG. 9, the WAP gateway 330 allocates an IP address and a port representing a remote address in the connection attempt process. There may be several ways to implement a protocol for this. The first method extends the remote CP protocol so that the remote control point 320 notifies the WAP gateway 330 of the connection request, and the home agent 310 also sends a response to the remote control point 320 and the WAP gateway 330. How to send to. The second method is a method in which the WAP gateway 330 looks at the connection attempt and response message without defining a new message. In this case, the WAP gateway 330 needs to be able to distinguish some header fields even if it is not a full parser.

In FIG. 9, home agent 310 first authenticates an access attempt from remote control point 320 and then determines an encryption scheme and receives information regarding the remote control point 320.

The device-terminal pair is then configured and the component is downloaded from the access server if necessary.

Thereafter, the home agent 310 records the IP and the web client port of the remote control point 320 requesting the connection, allocates one internal port, and allocates a NAT entry by combining with the internal IP address.

Then, the external IP address of the remote control point 320 and the port for multicast are added to the internal fixed multicast address / port entry. In addition, the multicast port number of the home agent 310 is allocated. The assignment entry is notified to the remote control point 320 via the remote CP protocol. The remote control point 320 sends a unicast packet to an external port and an external IP address when sending a multicast message.

It notifies the other remote control point that the new remote control point is connected. Assuming that multiple remote control points exist on the home network, multicast messages sent by any control point can be seen by other control points.

That is, although the current UPnP device architecture 1.0 specification does not have a specification for multiple UPnP control points, the present invention implements a vendor specification, for example, a security function, so that multicast messages from other control points can be usefully used. . To do this, a multicast message is received between remote control points.

2. Operation of the remote control point 320 in the embodiment of the present invention will be described with reference to the operation flowchart of FIG.

The remote control point 320 proceeds with the connection initialization when the operation starts. This process includes connection, authentication, NAT registration, etc. using the remote CP protocol, and also includes the configuration portion of the WAP gateway 330.

After the initialization is completed, it is checked whether the transmitted and received UPnP packets exist. Accordingly, if the transmitted / received packets exist, packet conversion is performed in the same process as the operation flowchart of FIG. 8.

If there is no UPnP packet transmitted and received, check whether there is a remote CP protocol packet. Accordingly, when the remote CP protocol packet is confirmed, the remote CP protocol process is performed in the same process as the operation flowchart of FIG.

In addition, if the remote CP protocol packet is not acknowledged, check whether there is a termination request from the remote control point. Accordingly, when the termination request is confirmed, the connection is terminated. The connection termination begins by informing the remote control point of the termination of the connection through the remote CP protocol, and the home agent 3100 may be configured to provide resources such as NAT information related to the remote control point. Returns this and informs the other remote control point of the fact, on the contrary, if the connection request is not confirmed, it is repeated from the initial stage described above.

In addition, the process of converting the UPnP message at the remote control point 320 in FIG. 7 will be described with reference to the operation flowchart of FIG. 10.

First, check whether there is a UPnP packet transmitted.

If it is confirmed that there is a received UPnP packet, the message filter 322 is passed to convert address information included in the message. The address information is sent to the remote control point 320 whenever a device address is added to the NAT table in the home network.

When the transmitted UPnP packet is confirmed, the unicast packet is transmitted to the public network as it is. This is because the address of the unicast packet is already translated to external addresses outside the home agent. Address translation at the remote control point 320 is as shown in the example diagram of FIG.

Also, in case of multicast packet, it is delivered as a copy to both connected home agent and other recognized remote control point. At this time, since it is transmitted in unicast form, NAT conversion is essential. To this end, the home agent 310 stores the necessary address information, remote CP information, and the like in the remote CP protocol data storage unit 314.

In FIG. 7, the remote CP protocol processing of the remote control point 320 will be described with reference to the operation flowchart of FIG.

First, determine the protocol message type. Message types of the remote CP protocol may be classified into connection initiation related messages, connection termination related messages, and information messages related to NAT notification and access of other remote control points.

At this time, if it is determined that the information message is determined whether there is a NAT notification.

Therefore, if there is a NAT notification, it records in the NAT table for message modification in the message filter 322.

If there is no NAT notification, it is determined whether the connection notification of another remote control point. Accordingly, the remote control point information is recorded in the data storage unit 324 when the remote control point is confirmed by the access notification of the other remote control point. On the contrary, the remote control point information is recorded by the data storage unit when the remote control point is confirmed by the connection termination notification of the other remote control point. Delete at 324.

When the protocol message type is determined to be the end of the connection, the connection termination message is transmitted, and when a response is received, the connection is terminated immediately or a timeout is set. At this time, the other control point is also notified of the termination of the connection.

In addition, if the protocol message type is confirmed as connection initiation, a connection request is made and waits. Subsequently, when the connection is granted, the unicast address to be used is transmitted, and when the authentication is performed from the home agent 310, the component is downloaded and the information transmitted from the home agent 310 is, for example, the home agent address and multicast. The port number, other remote control point information, and the like are stored in the data storage unit 324.

As described in detail above, the present invention can achieve the following effects.

First, a UPnP CP application built into a remote control point can run without realizing that it is remotely connected. That is, the UPnP API on the remote control point side is exactly the same as the normal UPnP API and is independent of the lower WAP protocol. Therefore, the present invention may be aware that the home agent access module mounted on the remote control point automatically accesses and initializes the home agent without interference of the UPnP CP application, and the UPnP CP application operates on the remote control point. You can select options for remote access.

Second, since the main UPnP function is installed in the remote control point, the home agent can be implemented on various platforms because only the basic UPnP function is installed. Therefore, when the present invention is implemented as a module, it can be added at a relatively low cost to a TV, a refrigerator, a home internet gateway, and the like.

Third, since the function of the remote control point is the same as that of the control point in the home, detailed control of the device in the home is possible.

Fourth, by supporting multiple remote control points, it is possible to expand the network by controlling a number of devices, such as villas and residences at the same time by using any remote control point.

The present invention exhibiting such an effect can be applied not only to a UPnP-based home network but also to a basic framework and flow on a UPnP-based home network. That is, any type of home network standard includes discovery, control, and event messages, and multicast messages are often used, so the methods proposed in the present invention can be applied.

Claims (10)

In the UPnP network system configured to enable UPnP message exchange in the public network by distributing UPnP functions among home agents and remote terminals, A home agent that multicasts with a home-based HTTP-based UPnP device, A remote control point (Remote CP) for exchanging multicast messages with the home agent by UPnP stack and WAP protocol processing; A WAP gateway means located between the home agent and the remote control point to perform conversion between the HTTP / TCP / IP protocol and the WSP * / WTP / WDP protocol so that the UPnP protocol can operate on the WAP stack as well as the TCP / IP stack. A distributed system of control point functions on a UPnP network characterized by a configuration. The home agent of claim 1, wherein the home agent In the home, the UPnP device converts the IP address dynamically assigned through DHCP or AutoIP and the port pairs used by the device to the external static IP and port pair of the home agent, and converts the external static IP and port of the remote control point. A network address translation (NAT) device that translates dynamic IP and port numbers in the home, A multicast / unicast converter that converts multicast messages sent by the device into unicast messages, Distributed control point functions on the UPnP network, which includes a remote CP protocol processing unit that forwards NAT table entries to the remote control point, exchanges messages for remote control point access during initialization, and message exchange for authentication. system. The network address translator of claim 2, wherein the network address translator is A system for distributing control point functions on a UPnP network, characterized in that it collects IP addresses and port numbers from discovery messages, device description messages, and service description messages to generate NAT table entries. The method of claim 1 wherein the remote control point is A multicast / unicast converter that converts multicast messages sent to home agents into unicast messages, A UPnP message filter that modifies UPnP messages containing an XML description document containing the IP address and port number for IP address and port number translation; Receiving a NAT table entry from the home agent, including a remote CP protocol processing unit for supporting the exchange of messages for the home agent connection and authentication during the initialization process, characterized in that the control point function distributed system on the UPnP network. The method of claim 1, wherein the WAP gateway means It communicates with home agent based on UPnP / GENA, SSDP, SOAP / HTTP / TCP, UDP / IP, and configures to communicate with remote control point based on UPnP / GENA, SSDP, SOAP / HTTP / WSP * / WTP / WDP. A distributed system of control point functions over a UPnP network. The method of claim 5, wherein the WSP * A control point function distribution system on a UPnP network, characterized in that the WSP protocol extends the message header to support some of the headers used in UPnP that are not supported in the conversion between HTTP and WSP. The method of claim 1, wherein the WAP gateway means It has a IP address and a port number representing each remote control point, and is configured to perform a kind of NAT (network address translation) function that converts the remote control point into a WSP / WDP address and a port number of the remote control point. (UPnP) Distributed control point function on a network. The method of claim 1, wherein the WAP gateway means A control point function distribution system on a UPnP network, characterized in that it is configured to transmit a duplicated multicast message transmitted from a device to multiple remote terminals simultaneously by referring to a NAT table entry. The method of claim 1, wherein the WAP gateway means Control point on a UPnP network, characterized in that it is configured to transmit a multicast message transmitted from any remote terminal to the home agent and simultaneously transmit the multicast message to a plurality of other remote terminals by referring to the NAT table. Functional distribution system. A home agent that communicates multicastly with a home-based HTTP-based UPnP device, a remote control point (Remote CP) that exchanges multicast messages with the home agent by a UPnP stack and WAP protocol processing, and a remote control point with the home agent The UPnP network system, which is located between control points and has a WAP gateway means for converting between the HTTP / TCP / IP protocol and the WSP * / WTP / WDP protocols so that the UPnP protocol operates on the WAP stack as well as the TCP / IP stack. To The home agent In the home, the UPnP device converts the IP address dynamically assigned through DHCP or AutoIP and the port pairs used by the device to the external static IP and port pair of the home agent, and converts the external static IP and port of the remote control point. Network address translation (NAT) that translates into dynamic IP and port numbers in the home, and multicast / unicast converters that convert multicast messages sent by devices into unicast messages, The remote control point It includes a multicast / unicast converter that converts multicast messages sent to home agents into unicast messages. The WAP gateway means It includes UPnP message filter that recognizes only URL address in message and remote CP protocol processing unit that receives NAT table entry from home agent and supports message exchange for connection and authentication between home agent and remote control point during initialization. A distributed control point function distribution system on a UPnP network.