KR100705576B1 - Voice over internet protocol system and method for guarantee quality of service - Google Patents

Abstract

The present invention monitors the QoS status of all connected sessions on the network and selects a session whose QoS is unstable, and if the session can be modified, refer to the supportable media information of the user agent UA. The present invention relates to a VIO IP system for guaranteeing QOS that is changed to media information suitable for a bandwidth of a selected session.

Description

VOICE OVER INTERNET PROTOCOL SYSTEM AND METHOD FOR GUARANTEE QUALITY OF SERVICE}

1 is a diagram illustrating a process of session modification through a general re-INVITE technique in a VoIP system.

2 is a diagram illustrating a schematic configuration of a VoIP system for guaranteeing QOS in a local SIP network according to the present invention;

3 is a diagram illustrating a process of guaranteeing QOS in a VoIP system of a local SIP network according to the present invention;

Explanation of symbols on the main parts of the drawings

100, 300: user agent 200: proxy server

210: bandwidth monitoring server 220: UA properties database

230: UA Media Information Database

The present invention relates to a VIO system and a method for ensuring QOS.

Voice Over Internet Protocol (VoIP) is a communication technology that provides voice telephony services and multimedia video conferencing using Internet protocols.It is a combination of IP networks and public switch telephone networks (hereinafter referred to as PSTN). It is used in the form of equipment and various application services.

Session Initial Protocol (SIP) is a signaling protocol for creating, modifying and terminating Internet-based multimedia service sessions. The role of such a signaling protocol is to exchange information for controlling a message session between subjects who want to exchange messages.

In order to make a call in a general telephone network, the process of pressing a dial number, listening for a waiting sound until the other party picks up the telephone receiver, and returning a line resource after the call is performed through control message transmission through signaling.

VoIP network using SIP is composed of user agent and SIP server. In particular, the SIP server includes a proxy / redirect server for call signaling, a location server for managing location information of a user agent, and a user agent. It consists of a register for managing the registration information of the user agent).

More specifically, a user agent is a part that operates with an actual user, and may be divided into a requesting UAC (client) and a response UAS (server), but in reality, both parts are one. It is included in the program.

The proxy server forwards the request message to the place where the actual message should be delivered. In other words, the proxy mode continues to receive and forward successive messages. However, in the redirect mode, the proxy mode delivers a SIP-URI to the client that can be requested without going through itself.

In addition, a register registers a user agent and, when a request is received from another user agent, provides a registered information so that a message can be delivered to the user agent. The authentication process also distinguishes between legitimate users.

The location server is a DB in which a user's location is registered, not a SIP UA, and information is exchanged between a location server and another SIP member by a method other than SIP.

To connect a session in such a VoIP system, Caller UA sends INVITE to a proxy server, and the proxy server determines the destination and sends INVITE to Callee UA. Accordingly, Callee UA selects one of the media requested by Caller UA by referring to Session Description Protocol (SDP) of INVITE and transmits 200 OK message. Even after the session is connected, if the session type, codec, IP address and port number are changed, the session can be modified by sending INVITE.

However, the SDP for setting the actual media is created and referenced in each UA. In this case, the UA simply contains the codec information it can support and selects the appropriate media from the UAs of the sending and receiving end, but the UA actually determines whether the session is established in an environment with sufficient bandwidth and the network. I don't know how much to reduce the load.

In addition, in order to modify the session after the session connection, the UA monitors the bandwidth adjustment of the entire network, and if necessary, re-INVITE is transmitted to the counterpart UA to perform media negotiation again. However, since UA cannot monitor the entire network, there is a problem that there is no way to modify the session to guarantee QoS due to network bandwidth adjustment.

Accordingly, an object of the present invention is to solve the above problems, by monitoring the overall state of the SIP network by modifying the session by forcibly adjusting the constraint / allowance of the media (media) constituting the session according to the bandwidth state The present invention provides a VIO system for guaranteeing QOS to guarantee QOS of user agents participating in a network.

According to an aspect of the VIO IP system to ensure the QOS according to the present invention for achieving the above object, to monitor the QOS status of all connected sessions on the network to the QOS unstable session And a session control server for changing the media information suitable for the bandwidth of the selected session when session modification is possible with reference to supportable media information of the user agent UA.

The session control server has signaling information and supportable media information of user agents (UAs) of all connected sessions on the network.

The supportable media information of the user agents UA includes media list information of a currently connected session and media list information available in each connected session.

The available media list information includes at least one media information of video media and audio media information.

When the selected session can be modified, the session control server sets a header indicating a source and a destination address to send an INVITE message to the user agent UA of the selected session. send.

The session control server includes a bandwidth monitoring server for monitoring a bandwidth state of each session connected on the network, a UA registration database for storing registration information of user agents (UAs) of all sessions connected on the network. And a UA media information database for storing supportable media information of user agents (UAs) of all sessions connected on the network.

On the other hand, according to one aspect of the method of guaranteeing the QOS in the VIP system according to the present invention for achieving the above object, by monitoring the QOS status of all sessions connected on the network QOS (QoS) Selecting an unstable session and modifying the session by changing media information suitable for the bandwidth of the selected session with reference to supportable media information of a user agent UA for the selected session. Steps.

The modifying of the session may include setting a header indicating a source and a destination address of the selected session, and contents of the header to the user agent UA of the selected session, respectively. Transmitting the included INVITE message, receiving the grant message for the INVITE message from the user agent UA, and receiving the grant message transmitted from the user agent UA. Transmitting a response message and changing media information suitable for bandwidth of the selected session with reference to supportable media information of the user agent UA.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, detailed descriptions of preferred embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that reference numerals and like elements among the drawings are denoted by the same reference numerals and symbols as much as possible even though they are shown in different drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is a diagram illustrating a process of session modification through a general re-INVITE technique in a VoIP system.

As illustrated in FIG. 1, when a user A 10 transmits an INVITE message to a proxy server 20 (S1), the proxy server 20 may use a user A ( The INVITE message transmitted from the user A) 10 is transmitted to the user B 30 (S2).

Subsequently, the proxy server 20 transmits 100 Trying messages to the user A 10 (S3), and 180 ringing transmitted from the user B 30 (S4). After the message is delivered to the user A 10 (S5), the 200 OK message transmitted from the user B 30 (S6) to the user A 10 is transmitted (S5). S7), the user A 10 transmits an ACK message to the user B 30 through the proxy server 20 (S8 to S9).

As a result, negotiation between the users is terminated, and a session is opened (S10), so that User A (User A) 10 and User B (30) can communicate. will be.

At this time, in order for the user A 10 to modify the current session because the bandwidth of the connected session is insufficient or a problem occurs, the user B (Re-INVITE) message is sent through the proxy server 20 again. User B) (30) (S11 ~ S12), and receives a 200 OK message from the user B (User B) (30) (S13 ~ S14) the ACK message for this proxy server (Proxy server) (20 If the user B (S15 ~ S16) is transmitted via the (S15 ~ S16) is a modified session (modified session) is opened (S17).

2 is a diagram illustrating a schematic configuration of a VoIP system for guaranteeing QOS in a local SIP network according to the present invention.

As shown in FIG. 2, the VoIP system of the present invention includes a first user agent 100, a proxy server 200, and a second user agent 300, in particular, a user agent. (User Agent, hereinafter referred to as "UA") uses universal SIP-enabled terminals because no modification of the protocol is required.

The proxy server 200 has signaling information and supportable media information of UAs participating in a currently connected session.

In particular, the proxy server 200 stores media information that can be supported by UAs. An example of such media information is shown in Table 1 below.

Session UA1 UA2 current media available media ... One user A user B m = viedo RTP / AVP 14 a = rtpmap: 14 MPA / 90000 m = viedo RTP / AVP 14 26 a = rtpmap: 14 MPA / 90000 a = rtpmap: 26 JPGE / 90000 m = audio RTP / AVP 0 4 a = rtpmap: 0 PCMU / 8000 a = rtpmap: 4GSM / 8000 ... 2 user C user D m = audio RTP / AVP 4 a = rtpmap: 4 GSM / 8000 m = audio RTP / AVP 0 4 a = rtpmap: 0 PCMU / 8000 a = rtpmap: 4GSM / 8000 ... ... ... ... ... ... ...

In Table 1, the session connected between user A and user B is in a state of performing video communication, and it is possible to modify a session for media of video and audio.

In addition, the session connected between user C and user D is in the state of performing audio communication, and indicates that the session can be modified for audio media.

That is, when there are a plurality of sessions (session 1, session 2 ....) as shown in Table 1, the proxy server 200 refers to the media information that can be supported in each session. To find out whether the session is currently modifiable and how effective it is when the session is modified to obtain optimal results. In this case, the result value represents a list order of sessions requiring modification and media types of the session.

That is, the proxy server 200 transmits an INVITE message to UAs participating in a session requiring modification, and stores state information in transaction units until the final ACK is transmitted to the UA. The exchange ends until the end of the session modification flow.

After that, the bandwidth status of the session is monitored again, and the session modification is repeated by rank of the result list until the bandwidth is stabilized.

In particular, the proxy server 200 transmits an INVITE message to the UAs participating in the session to modify the session, so that the UAs know that the received INVITE message is received from the other party UA. To do this, set the <Form> and <To> tags in the INVITE message.

The proxy server 200 of the present invention includes a bandwidth monitoring server 210, a UA registration database 220, and a UA media information database 230. .

The bandwidth monitor 210 monitors the bandwidth of the network and reports the result to the proxy server if the result falls within the range set by the administrator, that is, if the service cannot be provided at the normal bandwidth. have.

The UA registration information database 220 stores the information of all registered UAs, and if the registration information of these UAs is large, it may be stored in a separate location server.

The UA media information database 230 stores supportable media information of UAs. Here, the media is largely divided into video and audio, UA supporting only audio, UA supporting only video, or audio and video. UA supporting all of them may be included.

3 is a diagram illustrating a process of guaranteeing QOS in a VoIP system of a local SIP network according to the present invention.

As shown in FIG. 3, when a user A 100 transmits an INVITE message to a proxy server 200 (S10), the proxy server 200 may use a user A. FIG. The INVITE message transmitted from the (User A) 100 is transmitted to the user B 300 (S20).

Subsequently, the proxy server 200 transmits a 100 Trying message to the user A 100 (S30), and transmits a 180 ringing message from the user B 300 (S40). Received) is delivered to the user A (User A) (100) (S50).

Subsequently, the proxy server 200 receives the 200 OK message from the user B 300 (S60), transfers it to the user A 100, and then transfers it to the user A 100 (S70). The ACK message transmitted from the (User A) 100 (S80) is transmitted to the user B 30 (S90).

As a result, negotiation between the user A 100 and the user B 300 is terminated to open a session (S100). ) And User B (300) can communicate.

As described above, a session between the user A 100 and the user B 300 is connected, and a proxy server 200 that monitors the overall state of the network and has session information of UAs. ) Checks the bandwidth state between User A (100) and User B (300).

As a result of the check, if the bandwidth of the currently connected session is insufficient or a problem has been determined that the session needs to be modified, the proxy server 200 may use the user A 100 and the user B (User B) ( In order to guarantee the QoS between 300, it is determined whether the session can be modified to secure the bandwidth stably.

In particular, when there are a plurality of sessions, the session that consumes the most bandwidth is selected, and whether or not the session can be modified to reduce the bandwidth consumption is determined.

At this time, if the session can be modified to modify the session between User A (User A) 100 and User B (User B) 300 is determined (S110), the header (Header) is set (S120) to the user A ( The INVITE message is transmitted to the user A) 100 and the user B 300 at step S130. In this case, the header includes information that allows each user to recognize the source from which the INVITE message is sent and the destination to which the INVITE message is sent. To set the header, the UA They are recognized as messages from the other party's UA, not the proxy server.

Accordingly, the user A 100 and the user B 300 each having received the INVITE message from the proxy server 200 are respectively sent to the proxy server 200. 200 OK message is sent (S140).

Accordingly, the proxy server 200 which receives the 200 OK message from each user transmits an ACK message to the user A 100 and the user B 300. In step S150, a modified session is opened (S160).

In the above, specific preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention attached to the claims. will be.

According to the present invention, by modifying the session by monitoring the overall state of the SIP network forcibly adjusting the constraint / allowance of the media (media) constituting the session according to the bandwidth state, the currently connected sessions occupy According to each bandwidth, there is an effect of efficiently controlling the QOSs of user agents (UAs) participating in the session.

Claims (10)

In the VIO system, If the session can be modified by monitoring the QOS status of all connected sessions on the network and referring to the user agent's supportable media information for the QOS unstable session, VIO IP system including a session control server for changing the media (media) information suitable for the bandwidth. The method of claim 1, The session control server, A VIP system having signaling information and supportable media information of user agents (UAs) of all connected sessions on the network. The method of claim 2, The supportable media information of the user agents (UAs) includes media list information of a currently connected session and media list information available in each connected session. The method of claim 3, wherein The available media list information includes a media information of at least one of the video (Video) media and audio (Audio) media information. The method of claim 1, The session control server, When the QOS is unstable, the session can be modified, and a header indicating a source and a destination address is set to the user agent UA of the QOS unstable session. VIO IP system to send an INVITE message. The method of claim 1, The session control server, A bandwidth monitoring server for monitoring a bandwidth state of each session connected on the network; A UA registration database for storing registration information of user agents (UAs) of all sessions connected on the network; And And a UA media information database for storing supportable media information of user agents (UAs) of all sessions connected on the network. In the method of guaranteeing QOS of VIO network, Monitoring the QoS status of all connected sessions on the network to select sessions that are unstable in QoS, For the selected session, modifying the session by changing media information suitable for the bandwidth of the selected session with reference to supportable media information of a user agent (UA). QOS guarantee method. The method of claim 7, wherein The supportable media information of the user agents (UAs) includes media list information of a currently connected session and media list information available in each connected session. The method of claim 8, And the media list information includes at least one of media information of video media and audio media information. The method of claim 7, wherein Modifying the session, Setting a header indicating a source address and a destination address of the selected session; Transmitting an INVITE message including the contents of the header to the user agent UA of the selected session; Receiving a grant message for the INVITE message from the user agent UA; Sending a response message to the grant message sent from the user agent (UA); And And changing media information suitable for bandwidth of the selected session by referring to supportable media information of the user agent (UA).

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