KR100769216B1 - Sip(session initiation protocol) service method for home network - Google Patents

Abstract

An SIP(Session Initiation Protocol) service method for a home network is provided to quickly and stably support transmission of a real time media stream between SIP terminals and support compatibility for any type of SIP terminals. Private IP addresses of private IP terminals and corresponding public IP addresses are registered in an SIP proxy server. An RTP(Real time Transport Protocol) session is generated in response to a request for a session by the private IP terminal or a public IP terminal. The private IP terminal and the public IP terminal transmit and receive an RTP media stream through a UDP(User Datagram Protocol) relay according to the generated RTP session.

Description

SIP service method for home network {SIP (Session Initiation Protocol) service method for home network}

1 is a diagram illustrating a configuration of a SIP service system for implementing a SIP service method for a home network according to an embodiment of the present invention.

2 is a diagram illustrating a procedure in which a private IP terminal (UAC) registers with a SIP proxy server in a SIP service method for a home network according to an embodiment of the present invention.

3 is a diagram illustrating a procedure for transmitting an RTP media stream between a private IP terminal (UAC) and a public IP terminal (UAS) due to a session request of a private IP terminal in a SIP service method for a home network according to an embodiment of the present invention. Showing drawings.

4 is a diagram illustrating a procedure for transmitting an RTP media stream between a private IP terminal (UAS) and a public IP terminal (UAC) due to a session request of a public IP terminal in a SIP service method for a home network according to an embodiment of the present invention. Showing drawings.

<Explanation of symbols for main parts of the drawings>

110,210,310,450 ... Private IP terminals 120,240,350,410 ... Certified IP terminals

130,230,340,420 ... SIP Proxy Server 140 ... Home Gateway

140r, 330,430 ... UDP Relay 140p, 220,320,440 ... Home SIP Proxy

The present invention relates to a Session Initiation Protocol (SIP) service method for a home network, and more particularly to a SIP UAC (User Agent Client) and a SIP UAS (NAS) in a network having a network address translation (NAT). The present invention relates to a SIP service method for a home network that processes a real-time transport protocol (RTP) session between a user agent server.

In the future, the network will evolve into the home network environment due to the rapid development of the Internet, information appliances, and the desire for customer convenience. In such a home network environment, private networks using NAT are expected to be built for each home rather than providing public IP (Internet Protocol) to all home terminals. Meanwhile, the Internet is gradually evolving from web-centric data traffic to services requiring real-time traffic such as teleconferencing and voice over IP (VoIP). Therefore, future networks should be able to provide services based on User Datagram Protocol (UDP), where arrival time is more important than the exact transmission of data depending on the service.

Currently, call establishment protocols for such a real-time transmission service include H.323 and Internet Engineering Task Force (IETF) SIP proposed by the most widely used International Telecommunications Union-Telecommunication Standardization Sector (ITU-T). Currently, most equipment and service providers support the H.323 protocol, but IETF's SIP protocol, with its many features and scalability, is expected to become commonplace in the future. In general, SIP is defined in the IETF RFC2543 document and is an application layer control protocol for establishing, modifying and terminating sessions or calls for multimedia communication such as video and voice. SIP is a client-server based protocol that is deployed in the form of a call originator calling for the other party to join the session. In addition, session information to be expressed in a session for multimedia service communication is described using a Session Description Protocol (SDP).

However, in a home network environment having a private network using NAT, there is a limitation in providing such a SIP service. That is, the success of RTP media streams using SIP between UAC and UAS located in a private network depends on the type of NAT and the structure of the network.

NAT is an address translator used to translate private IP addresses into public IP addresses at the network layer, which can save IP addresses by allowing multiple private terminals to share a public IP. NAT is largely divided into static, dynamic, and network address and port translation (NAPT) methods. Especially, the NAPT method that maps internal IP and ports to public IP and ports is widely used. The NAPT scheme can be further classified into a full cone, a restricted cone, a port restricted cone, and a symmetrical scheme.

If a SIP proxy server is configured in the home network, the routing of SIP call requests is handled without problem, regardless of the public or private network. However, processing of RTP sessions can be problematic depending on conditions. That is, RTP processing does not have any problem if the home network is a public network. However, if the home network is a private network, whether or not it is handled depends on the type of NAT of the home network.If a full cone NAT is configured, the STNA (Simple Traversal of UDP through NAT) that exists in the public network can be processed and is symmetrical. If not, it is impossible to have STUN. If the NAT of the home network is a symmetric NAT, a TURN (Traversal Using Relay NAT) server can be configured in the public network to enable RTP processing. However, TURN has problems such as bandwidth waste and delay due to media relay requests from a large number of clients.

The present invention has been made in view of the above, and in a home network environment having a private network, by implementing a function such as TURN on a home gateway, a simpler and more efficient UDP relay than TURN is provided to provide smooth RTP. An object of the present invention is to provide a SIP service method for a home network that enables processing of a session.

In order to achieve the above object, a SIP service method for a home network according to an aspect of the present invention,

In the SIP service method for a home network to enable smooth processing of RTP session between a private IP terminal and a public IP terminal,

a) registering a pair of private IP addresses for the private IP terminals and corresponding public IP addresses with the SIP proxy server;

b) creating an RTP session in response to a session request by the private IP terminal or a public IP terminal; And

c) sending and receiving an RTP media stream between the private IP terminal and the public IP terminal through a UDP relay by the generated RTP session.

Here, the registration procedure of the private IP terminal to the SIP proxy server in step a),

a-1) sending a registration request message to a home SIP proxy of a home gateway by a user agent client (UAC) having a private IP;

a-2) the home SIP proxy receiving the registration request message, converting the contact header of the SIP message into a public IP address known to the SIP proxy server, and transmitting the SIP header to the SIP proxy server;

a-3) after the SIP proxy server receiving the SIP message processes the registration procedure, informing that the registration is completed with the home SIP proxy of the home gateway; And

a-4) the home SIP proxy receiving the registration completion notification, changing the contact header of the SIP message back to (private IP address: port) corresponding to the ID of the corresponding UAC, and notifying the completion of registration to the UAC; Is done.

In addition, in the step b), the step of creating the RTP session by the session request by the private IP terminal,

b-1) the originating private IP terminal sending an invite message to the called public IP terminal via the home SIP proxy and the SIP proxy server;

b-2) the incoming public IP terminal receiving the invitation message sending an acceptance message to the calling private IP terminal via the SIP proxy server and the home SIP proxy;

b-3) the originating private IP terminal receiving the acceptance message sends a confirmation message to the called public IP terminal through the home SIP proxy and the SIP proxy server.

In addition, the step of generating an RTP session by the session request by the public IP terminal in step b),

b'-1) the external public IP terminal sending an invitation message to the private IP terminal via the SIP proxy server and the home SIP proxy;

b'-2) the private IP terminal receiving the invitation message sending an acceptance message to the calling public IP terminal through a home SIP proxy and a SIP proxy server;

b'-3) sending the acknowledgment message to the destination private IP terminal via the SIP proxy server and the home SIP proxy.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In addition, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless otherwise stated.

Now, a SIP service method for a home network according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a configuration of a SIP service system for implementing a SIP service method for a home network according to an embodiment of the present invention.

Referring to FIG. 1, a SIP service system is connected to a public IP network with a private IP terminal 110 using a private IP belonging to a private network, and forms an RTP session with the private IP terminal 110 to exchange data. The public IP terminal 120, a SIP proxy server 130 connected to the public IP network to manage registration information of the SIP terminal and relaying a message sent by the calling terminal to the destination terminal, and a SIP message as an entrance to the private network. It is composed of a home gateway 140 having a home SIP proxy (140p) and a UDP relay service for UDP communication to change the private IP and public IP by changing the.

In the SIP service system as described above, the private network is connected to the public IP terminal 120 and the SIP proxy server 130 through the home gateway 140 through the public IP network. The home gateway 140 serves as an entrance to the home network of each home, and is equipped with a home SIP proxy 140p and a UDP relay service 140r to enable NAT and transmission of an RTP media stream. That is, the home SIP proxy 140p of the home gateway 140 changes the SIP message sent by the internal private IP terminal 110 based on the (private IP: port)-(public IP: port) information to change the SIP of the public network. The message is transmitted to the proxy server 130 or the SIP message received from the SIP proxy server 130 is changed and sent to the internal private network. The UDP relay service 140r mounted in the home gateway 140 serves as a relay for transmitting the actual RTP media stream after SIP signaling is completed. In addition, the SIP proxy server 130 of the public network registers the private IP terminal 110, and serves to relay SIP messages between the private IP terminal and the private IP terminal or between the private IP terminal and the public IP terminal. The public IP terminal 120, which is connected to the public network and communicates with the private IP terminal 110 through the SIP proxy server 130, means not only the SIP terminal itself directly connected to the public network, but also any type of NAT. It also includes a public IP terminal serving as a gateway of a third private network having a network.

That is, to form an RTP session with a SIP terminal in a private network having any other NAT other than the method through the home SIP proxy 140p and the UDP relay service 140r, the structure or form of the private network need not be considered. The session only needs to be successfully exchanged to a public IP terminal (gateway) to enter the private network. This is because the subsequent procedure between the public IP terminal and the SIP terminal in the private network is successfully performed according to the NAT policy of the private network.

Thus, the system of FIG. 1 enables SIP services between the private IP terminal 110 and the public IP terminal 120, and between the private IP terminal 110 and a private IP terminal existing in any other private network.

Then, a SIP service method for a home network according to an embodiment of the present invention will be described with reference to FIGS. 2 to 4 based on the SIP service system as described above.

2 is a diagram illustrating a procedure in which a private IP terminal (UAC) registers with a SIP proxy server in a SIP service method for a home network according to an embodiment of the present invention.

Referring to FIG. 2, first, a pair of private IP addresses for private IP terminals and a corresponding public IP address is registered in a SIP proxy server according to a SIP service method for a home network according to an embodiment of the present invention.

That is, the UAC 210 having a private IP preferentially sends a registration request message to the home SIP proxy 220 of the home gateway (step 1). In this case, the SIP message includes a pair of (UAC's private IP address: port)-(home gateway's public IP address: port), and in particular, the contact header includes a UAC (210), such as <ID @ private IP address: port>. ) 'S private IP address and ID are listed so that the UAC can be easily found by the ID of SIP message coming from public IP in the future.

The home SIP proxy 220 receiving the registration request message from the UAC 210, prior to requesting registration with the SIP proxy server 230, the public IP address of which the SIP proxy server 230 can know the contact header of the SIP message. After switching to step 2, the registration request message is transmitted to the SIP proxy server 230 (step 3). Accordingly, after processing the registration procedure (step4), the SIP proxy server 230 sends a response (for example, 200 OK) to the home SIP proxy 220 of the home gateway (step 200). After receiving the response, the home SIP proxy 220 changes the contact header of the SIP message back to (private IP address: port) corresponding to the ID of the corresponding UAC (step 6), and then the registration completion message 200 to the UAC 210. OK) (step 7). This completes the registration process.

When the registration of the private IP terminal to the SIP proxy server is completed in this way, an RTP session is generated by the session request by the private IP terminal or the public IP terminal. First, the process of creating an RTP session by a session request by a private IP terminal will be described.

3 is a diagram illustrating a procedure for transmitting an RTP media stream between a private IP terminal (UAC) and a public IP terminal (UAS) due to a session request of a private IP terminal in a SIP service method for a home network according to an embodiment of the present invention. Figure showing.

Here, first, it is assumed that the UAC of the private network has a terminal registered in the SIP proxy server.

Referring to FIG. 3, first, a UAC 310 of a private network sends an invitation message to a home SIP proxy 320 of a home gateway to establish a session (step 1). Then, the home SIP proxy 320 changes the contact header of the invitation message to a public IP that can be recognized by the public network as shown in FIG. 2 (step2), and also in the body part of the message. Session Description Protocol (SDP) IP is also changed to public IP (step 3). It then requests to prepare for accepting the RTP session request on the UDP relay service 330 of the home gateway (step4), and sends an invitation message to the SIP proxy server 340 (step5). Upon receiving the invitation message, the SIP proxy server 340 checks the ID of the UAS 350 in the message, processes the call (step 6), and transmits the invitation message to the UAS 350 (step 7). Upon receiving the invitation message, the UAS 350 transmits an acceptance message (200 OK message) to the SIP proxy server 340 (step 9), and the SIP proxy server 340 processes the call (step 10) to the home of the UAC side. The accept message (200 OK message) is forwarded to the SIP proxy 320 (step11). Thereafter, the home SIP proxy 320 notifies the UDP relay service 330 of the home gateway that it is ready to open an RTP session (step13), and then changes the contact header of the SIP message and the SDP IP of the UAS 350 (step12). (14) A acceptance message (200 OK message) is transmitted to the UAC 310 (step 15). The UAC 310 receiving the acceptance message (200 OK message) sends an acknowledgment (ACK) message to the SIP proxy server 340 via the home SIP proxy 320 (steps 16 and 17) in response thereto. In step 340, the acknowledgment (ACK) process is performed (step 18), and the acknowledgment (ACK) message is transmitted to the UAS 350 (step 19).

After the SIP signaling process is completed by the above procedure, the UAS 350 receiving the acknowledgment message transmits the RTP data to the UAC 310 via the UDP relay service 330 (steps 20 and 21). This will open the RTP session successfully. During the RTP session, the UAC 310 and the UAS 350 may exchange data via the UDP relay service 330 (steps 22 and 23). Here, the UDP relay service 330 is present in the form of an application program on the home gateway connected to the calling private IP terminal (UAC) 310, and the calling IP terminal (UAC) 310 and the destination IP terminal (UAS). Relay the RTP data transmission between 350.

In the above series of steps, the 100 Trying and 180 Ringing messages are omitted (see step 8), but those skilled in the art, despite the omission of these messages, are aware of the private IP terminal (UAC) 310 and the public IP terminal as described above. It will be understood that the procedure of transmission of the RTP media stream between the (UAS) 350.

On the other hand, after the transmission and reception of the RTP data is completed, the UAC 310-home SIP proxy 320-SIP proxy server in a hop-by-hop manner in the UAS 350 or UAC 310 ( 340)-When the BYE request message is transmitted through the path of the UAS 350, a 200 OK response message is transmitted in a hop-by-hop manner in response to this to release the call setup.

As described above, the transmission procedure of the RTP media stream between the private IP terminal (UAC) and the public IP terminal (UAS) due to the session request of the private IP terminal has been described. Next, a description will be given of the transmission procedure of the RTP media stream between the private IP terminal (UAS) and the public IP terminal (UAC) due to the session request of the public IP terminal.

4 is a diagram illustrating a procedure for transmitting an RTP media stream between a private IP terminal (UAS) and a public IP terminal (UAC) due to a session request of a public IP terminal in a SIP service method for a home network according to an embodiment of the present invention. Figure showing.

Here, first, it is assumed that a UAS of a private network has a terminal registered in a SIP proxy server.

Referring to FIG. 4, first, the UAC 410 of a public network sends an INVITE message to the SIP proxy server 420 to establish a session (step 1). Then, the SIP proxy server 420 sends a INVITE message to the home SIP proxy 440 after step 2 (step 2). The home SIP proxy 440 receiving the message changes the SDP IP of the UAC in the body portion of the message (step 4) and requests on the home relay's UDP Relay service 430 to accept the RTP session request. After that (step5), the UAS (450) transmits an invitation (INVITE) message (step6). The UAS 450 of the private network receiving the INVITE message sends a 200 OK message to the home SIP proxy 440 (step 8). Thereafter, the home SIP proxy 440 changes the SDP IP of the UAS 450 (step 9), notifies the UDP relay service 430 of the home gateway that it is ready to open an RTP session (step 10), and then executes the SIP proxy server ( In step 420, an OK (200 OK) message is transmitted. After receiving the 200 OK message, the SIP proxy server 420 transfers the 200 OK message to the UAC 410 after the call processing procedure (step 12). After receiving the 200 OK message, the UAC 410 transmits an acknowledgment (ACK) message to the SIP proxy server 420 in response (step 14), and the SIP proxy server 420 undergoes a verification process (step 14). In step 15, an acknowledgment (ACK) message is transmitted to the home SIP proxy 440 (step 16). The home SIP proxy 440, which has received the acknowledgment (ACK) response, transmits an acknowledgment (ACK) response to the UAS 450 again (step 17). This completes the SIP signaling process.

After the SIP signaling process is completed by the above procedure, the UAS 450 receiving the acknowledgment (ACK) message transmits the RTP data to the UAC 410 via the UDP relay 430 (steps 18 and 19). This will open the RTP session successfully. During the RTP session, the UAC 410 and the UAS 450 may exchange data through the UDP relay service 430 (steps 20 and 21). Here, the UDP relay service 430 is present in the form of an application program on the home gateway connected to the destination private IP terminal (UAS) 450, and the originating public IP terminal (UAC) 410 and the destination private IP terminal (UAS). Relay RTP data transmission between 450

In the above series of steps, the 100 Trying and 180 Ringing messages are omitted (see step 7), but those skilled in the art, despite the omission of these messages, are aware of the above-mentioned private IP terminal (UAS) and public IP terminal (UAC). Understand the transmission procedure of the RTP media stream between.

Meanwhile, after the transmission and reception of RTP data is completed, the UAC 410-SIP proxy server 420-home SIP proxy 440-UAS 450 in a hop-by-hop manner in the UAS 450 or the UAC 410. When the BYE request message is transmitted through the path of the BYE, a 200 OK response message is transmitted in a hop-by-hop manner in response to this to release the call setup.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, the SIP service method for the home network according to the embodiment of the present invention is a home SIP proxy on the home gateway to solve the problem of bandwidth waste and delay of the conventional symmetric method using the NAT and TURN server. And distributed processing by implementing the UDP relay service, it is possible to more quickly and stably support the transmission of the real-time media stream between SIP terminals. In addition, the present invention does not have a special requirement for the SIP user agent has the advantage that it is compatible with any type of SIP terminal.

Claims (10)

In the SIP service method for a home network to enable smooth processing of RTP session between a private IP terminal and a public IP terminal, a) registering a pair of private IP addresses for the private IP terminals and corresponding public IP addresses with the SIP proxy server; b) creating an RTP session in response to a session request by the private IP terminal or a public IP terminal; And c) sending and receiving an RTP media stream between the private IP terminal and the public IP terminal through a UDP relay by the generated RTP session. In claim 1, In step a), the registration procedure of the private IP terminal to the SIP proxy server is a-1) sending a registration request message to a home SIP proxy of a home gateway by a user agent client (UAC) having a private IP; a-2) the home SIP proxy receiving the registration request message, converting the contact header of the SIP message into a public IP address known to the SIP proxy server, and transmitting the SIP header to the SIP proxy server; a-3) after the SIP proxy server receiving the SIP message processes the registration procedure, informing that the registration is completed with the home SIP proxy of the home gateway; And a-4) the home SIP proxy receiving the registration completion notification, changing the contact header of the SIP message back to (private IP address: port) corresponding to the ID of the corresponding UAC, and notifying the completion of registration to the UAC; SIP service method for a made home network. In claim 1, In the step b), the step of creating the RTP session by the session request by the private IP terminal, b-1) the originating private IP terminal sending an invite message to the called public IP terminal via the home SIP proxy and the SIP proxy server; b-2) the incoming public IP terminal receiving the invitation message sending an acceptance message to the calling private IP terminal via the SIP proxy server and the home SIP proxy; b-3) a SIP service method for a home network, comprising the step of sending a confirmation message to a called public IP terminal through a home SIP proxy and a SIP proxy server receiving the acceptance message. In claim 3, The home SIP proxy receiving the invitation message from the private IP terminal in step b-1) changes the contact header and SDP IP of the invitation message to the public IP and prepares to accept the RTP session request. A SIP service method for a home network, wherein the SIP proxy server checks the ID of a public IP terminal in a message and processes the call. In claim 3, In step b-2), the SIP proxy server receiving the acceptance message (200 OK message) processes the call, and the home SIP proxy notifies that the home gateway is ready to open an RTP session to the UDP relay service, and contacts the SIP message. SIP service method for a home network, characterized by changing a header and an SDP IP. In claim 1, The UDP relay service in step c) exists in the form of an application program on the home gateway connected to the originating private IP terminal, and relays the RTP data transmission between the originating private IP terminal (UAC) and the destination IP terminal (UAS). SIP service method for home network characterized in that. In claim 1, In the step b), generating the RTP session by the session request by the public IP terminal, b'-1) the external public IP terminal sending an invitation message to the private IP terminal via the SIP proxy server and the home SIP proxy; b'-2) the private IP terminal receiving the invitation message sending an acceptance message to the calling public IP terminal through a home SIP proxy and a SIP proxy server; b'-3) A SIP service method for a home network, comprising the step of sending a confirmation message to an incoming private IP terminal via a SIP proxy server and a home SIP proxy, receiving the acceptance message. In claim 7, In step b'-1), the SIP proxy server receiving the INVITE message from the UAC of the authorized network processes the call and transmits the invitation message to the home SIP proxy, and the home SIP proxy receiving the message is in the message. A SIP service method for a home network, comprising: changing the SDP IP of an existing UAC and requesting preparation for accepting an RTP session request on a UDP relay service of a home gateway. In claim 7, In step b'-2), the home SIP proxy that receives the 200 OK message from the UAS of the private network changes the SDP IP of the UAS, notifies that it is ready to open an RTP session to the UDP relay service of the home gateway, and SIP Proxy server is a SIP service method for a home network, characterized in that the call processing. In claim 7, In step c), the UDP relay service is present in the form of an application program on a home gateway connected to the destination private IP terminal, and relays RTP data transmission between the originating public IP terminal (UAC) and the destination private IP terminal (UAS). SIP service method for a home network, characterized in that.

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