KR20080021490A - Method of providing qos between end to end using sip/sdp in wire and wireless integrated network - Google Patents

Abstract

A method for supplying QoS(Quality of Service) by using SIP(Session Initiation Protocol)/SDP(Session Description Protocol) between ends in a wire/wireless integration network is provided to map classes for QoS between a wireless LAN(Local Area Network) and a Diffserv-over-MPLS(Multi Protocol Label Switching) network, and to set a multimedia session by using SIP/SDP, thereby offering QoS between ends even in a wire/wireless integration environment. A sending terminal(301) allocates radio network resources(303). QoS information of the terminal(301) is transmitted to an SIP proxy server(315) by using an invite message(304). The server(315) selects an LSP(Lable Switching Path), and maps traffic between terminals(301,313) with the selected LSP(305). After QoS setup is finished, an invite message is delivered to the receiving terminal(313,306). The receiving terminal(313) allocates radio network resources(307). The receiving terminal(313) writes session setup results in SDP type, and sends a ringing message to the sending terminal(301,308). Both terminals(301,313) exchange response messages to complete session setup(309-311).

Description

METHODS OF PROVIDING QoS BETWEEN END TO END USING SIP / SDP IN WIRE AND WIRELESS INTEGRATED NETWORK}

FIG. 1A illustrates an operation procedure of an EDCA according to an access category (AC) in a WLAN.

1B is a diagram showing the structure of a SIP system for providing a multimedia service in the Internet;

2 is a view showing the overall configuration for providing a service quality in a wired and wireless integrated network according to the present invention,

3 is a schematic diagram showing functional blocks of respective components according to the present invention;

4 is a flowchart illustrating a signaling procedure for providing a quality of service according to the present invention.

* Explanation of symbols for main parts of the drawings

202a / b: user terminal 210a / b: broadband access network

212: wireless LAN 214: wireless MAN

216: Ethernet 220: differential service MPLS network

222: edge router (LER) 224: switch router (LSR)

230: SIP server 232: SIP location / redirection module

234: Q-SIP module 240: CAC

250: software module

The present invention relates to a method for guaranteeing quality of service (QoS) between end-to-end in a wired / wireless converged network, and more particularly, to SIP and end-to-end in a wired / wireless integrated network. The present invention relates to a method for providing quality of service (SQ) using SIP / SDP.

Recently, the IEEE 802.11e standard has been published to guarantee the quality of service in a wireless LAN (LAN) as the high-speed wireless LAN is expected to be used as the broadband subscriber access network. In other words, IEEE 802.11 Working Group (WG) has standardized IEEE 802.11e to solve the QoS (QoS) problem of 802.11, and IEEE 802.11e is based on the existing 802.11 802.11 Hybrid Coordination Function to provide QoS. ) Is newly added. HCF consists of a medium (channel) approach called Enhanced Distributed Channel Access (EDCA) and HCF Controlled Channel Access (HCCA). Contention-based channel access (EDCA) is a contention-based channel approach, and HCCA (HCF controlled channel access) is a polling-based non-competition-based channel approach.

As shown in FIG. 1, the EDCA uses four different access categories (ACs) using minimum / maximum contention window size (Min / Max Contention Window Size), AIFS (Arbitration InterFrame Space), and TXOP (Transmission Opportunity). Provides differentiated services by dividing into access categories. Referring to FIG. 1A, according to the IEEE 802.11 standard, each station detects an idle state of a channel in order to reduce collisions, and at least performs a backoff of a DIF (DCF Interframe Space) period, and a continuous RTS. The frame is transmitted with a short interframe space (SIFS) period between the CTS, Data, and ACK frames. In EDCA, each station performs a backoff according to the priority of an access category (AC). That is, the higher the access category (AC) with a higher priority (priority), the less time the backoff time (Backoff Time) than the AC has a lower priority to access the channel preferentially. In FIG. 1A, the access category AC is divided into voice AC_VO, video AC_VI, best AC_BE, and background AC_BG according to the priority, and the AIFS period is shortened according to the priority. Can be.

HCCA provides a Controlled Access Phase (CAP), unlike the existing Point Coordition Function (PCF). Existing PCF has service cycle for each node (station) based on superframe, but HCCA additionally allocates non-competitive CAP based on beacon based on beacon, and each station (STA) The QoS required by the user side is guaranteed by using TXOP for the media access time allocated for.

Meanwhile, SIP / SDP was developed by the IETF as a protocol for establishing a session for a multimedia service. FIG. 1B illustrates the structure of a Session Initiation Protocol (SIP) system. When the originating user agent 102 requests the originating SIP proxy server 110-1 to connect with the called party 104, the originating SIP proxy server 110 is connected. -1) cooperates with the destination SIP server 110-2, the DNS server 120, and the location server 130 to establish a session with the destination user agent 104.

The main functions of SIP are the multimedia session setup, modification, and release functions as shown in Table 1, and additionally provide functions for reporting and transmitting status of the current session.

. Location provision service for the other terminal. Session connection settings. Session release. Modifications to Current Session. Current state information transmission. Instance message delivery

The Session Description Protocol (SDP) provides additional information about the media to establish a session. That is, by additionally describing and providing a port number, a media format, a media encoding method, etc. for establishing a session, it is possible to provide a more flexible connection environment when configuring a session using SIP.

However, IEEE 802.11e has been proposed for quality assurance and supplements QoS guarantee to some extent than existing IEEE 802.11, but is limited to wireless network environment only. In addition, the differential service MPLS network (DiffServ-Over-MPLS) shows the quality assurance method only in the wired network. In the future, the user environment will be end-to-end, and there will be a mixture of wired and wireless networks. Therefore, each quality assurance technology alone is difficult to guarantee end-to-end quality in wired / wireless converged networks, and it is necessary to establish a connection for end-to-end quality assurance and to exchange related information.

In this regard, the techniques known to date have suggested a mapping structure between EDCA AC (Access Category) of IEEE 802.11e and class-type of DiffServ in QoS class mapping between heterogeneous networks.

However, since such a mapping structure alone does not provide QoS, signal processing for end-to-end connection establishment is required. In the conventional signal processing, there is a method using a resource reservation protocol (RSVP), but this method can not be delivered to the other party by describing all the QoS resources, and the resource reservation protocol (RSVP) itself is heavy and difficult to mount on a wireless terminal There is a problem.

The present invention has been proposed to solve the above problems, and an object of the present invention is to provide a QoS providing method for each network proposed in an integrated environment of a wired network and a wireless network, and only an authenticated user can In a wired / wireless converged network that provides this guaranteed service, a method of providing quality of service (QoS) is provided between S-IP and SDP (SIP / SDP) between end-to-end networks.

In order to achieve the above object, according to the present invention, a calling terminal is connected to a first WLAN, a called terminal is connected to a second WLAN, and the first WLAN and the second WLAN are differentiated services. In the wired / wireless integrated network connected through the MPLS backbone network to provide a,

A first step of the originating terminal allocating a radio network resource according to an access point and a traffic specification of the first WLAN; When the wireless network resource is allocated between the originating terminal and the access point by the first step, the QoS information of the originating terminal is described in the SDP to use an INVITE message. Transmitting to an SIP proxy server; The SIP proxy server may select a preconfigured label switching path (LSP) based on a source address and a destination address, and map traffic between terminals to a selected label switching path (LSP); A fourth step of delivering an invite message to the called terminal after setting the quality of service (QoS) for the MPLS backbone network; A fifth step of checking, by the destination terminal, an SDP message transmitted and allocating an access point and a radio network resource of the second WLAN; A sixth step of, after the allocation of the radio network resources in the second WLAN, the terminating terminal prepares a session establishment result as an SDP and transmits a ringing message to the calling terminal; And completing the session establishment by exchanging response messages by both terminals.

In the third step, when receiving the SDP in which the quality of service (QoS) information is described, the SDP information is transferred to the Q-SIP module, and the Q-SIP is transmitted. The module maps the quality of service class of the wireless network to the quality of service class of the wired network, and the class mapping maps three HCCAs of the wireless LAN with NCT, EF, and AF4 of the differential network DSCP, and AC_VI of the EDCA is the AC_VO maps AF2, EDCA AC_BE maps AF1, and EDCA AC_BK maps BE.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a view showing the overall configuration for providing a service quality in the wired and wireless integrated network according to the present invention, Figure 3 is a schematic diagram showing the functional blocks of each configuration for implementing the present invention.

As shown in FIG. 2, the wired / wireless integrated network to which the present invention is applied, a broadband access network 210 providing broadband access to subscribers, and a differential service MPLS network 220 which is a backbone network for providing a differential service in a wired network. And the differential service MPLS network 220 includes an edge router 222 for connecting the broadband access network to which the subscriber belongs to the backbone network and switch routers 224 constituting the backbone network. The broadband access network 210 may be composed of a wireless LAN 212, a wireless MAN 214, an Ethernet 216, etc. In the embodiment of the present invention, the broadband access network 210 is a wireless LAN 212 according to the IEEE 802.11e standard. The case will be described mainly.

According to the present invention, a component for providing a service quality in a wired / wireless integrated network is largely composed of three components. That is, a wireless terminal (QSTA) 202 equipped with a Session Initiation Protocol (SIP) / Session Description Protocol (SDP) software module 250 and a SIP proxy server 230 capable of processing a quality of service (QoS) function. proxy server) and a Connection Admission Control (CAC) 240 that manages network resources based on the SIP proxy server 230. The SIP proxy server 230 is composed of a SIP location / redirection module 232 and a Q-SIP proxy module 234.

First, the terminal 202 is equipped with a SIP / SDP software module 250 as a user terminal connected to an access point of the wireless LAN 212, establishes a multimedia session using the existing SIP, and additional QoS when establishing the session Information is described in the Session Description Protocol (SDP). The SDP is transmitted to the SIP proxy server 230, and the SIP proxy server 230 passes the session information to the Q-SIP module 234 when QoS information is described in the SDP. The Q-SIP module 234 interworks with the CAC 240 of the backbone network to provide a network resource allocation function.

The function of the network for providing a service quality in the wired / wireless integrated network according to the present invention is distributed in the SIP proxy server 240 and the network management servers managing each network, and the entire functional blocks are shown in FIG. 3. Similarly, the service profile 261, the fine wire management module 262, the connection acceptance control 263, the network information database 264, the node configuration module 265, the service quality controller 266 of the broadband access network, MPLS edge router The service quality controller 270 is made. The service quality controller 266 of the broadband access network is further divided into the service quality controller 267 of the WLAN, the service quality controller 268 of the DPCN, and the service quality controller 269 of the wireless MAN.

A procedure for providing a service quality according to the present invention in the wired / wireless integrated network structure will be described with reference to FIG. 4.

4 is a flowchart illustrating a signaling procedure for providing a quality of service according to the present invention, and illustrates a procedure for establishing a session between the SIP user agent a 301 and the SIP user agent b 313 in consideration of the quality of service. It is.

Referring to Fig. 4, QSTA-A 301 is a wireless terminal 202a connected to a first wireless LAN 212a according to IEEE 802.11e, and is equipped with SIP user agent a, and QSTA-B 313 A SIP user agent b is mounted as a wireless terminal 202b connected to a second wireless LAN 212b according to IEEE 802.11e, and the first wireless LAN 212a and the second wireless LAN 212b provide a differential service. Connected via the MPLS backbone network (Diffserv-over-MPLS: 220). The first WLAN 210a includes access points (QAPs) for connecting to wireless terminals belonging to the first WLAN 210a, and the second WLAN 210b includes a second WLAN 210b. Access Points (QAPs) for connecting with wireless terminals belonging to are included.

Looking at the detailed quality of service (QoS) session connection procedure in such a configuration, QSTA-A (301) uses a traffic specification (TSPEC) before starting the session establishment using the session initiation protocol (SIP) In step 303, a quality of service access point (QAP) 314 of the first WLAN 210a and a resource for a wireless network are allocated. This is to confirm network resources between the QSTA-A 301 and the QAP 314 in advance, and to terminate the session early if network resources are insufficient.

When a wireless network resource is allocated between the QSTA-A 301 and the QAP 314, the QSTA-A 301 describes the QoS information in the SDP and transmits it to the SIP proxy server 315 using an INVITE message. (304) The information described in the SDP is shown in Table 2 below.

SDP Property Explanation m = video 23422 RTP / AVP 31 Media information a = rtpmap: 31 H261 / 9000 Media attribute for codec a = curr: qos local sendrecv Media attribute for QoS a = curr: qos remote none a = des: qos mandatory local sendrecv a = des: qos mandatory remote sendrecv

In Table 2, it can be seen that basic media information and QoS information for media are described. QoS information is processed by dividing it into "curr" and "des" states. "curr" indicates the current QoS setting state, and "des" indicates the required QoS setting state. Looking at "a = curr: qos local send sendrecv" of Table 2, it can be seen that resource reservation for both directions between the current QSTA-A 301 and the QAP 314 has been successfully allocated.

The INVITE message generated by the QSTA-A 301 is transmitted to the SIP proxy server 315. When the SIP proxy server 315 receives the SDP describing the QoS information, the SIP proxy server 315 passes the SDP information to the Q-SIP module 234. The Q-SIP module 234 selects a preconfigured DiffServ-over-MPLS Label Switching Path (LSP) based on a source address and a destination address (source / destination), and maps traffic between terminals to the selected LSP (305). ). At this time, if there is no free resource for the backbone (316) network, the session is terminated according to QoS conditions.

In the present invention, the differential service MPLS (DiffServ-over-MPLS) configuration method applies a virtual overlay network concept and sets and manages paths according to classes of the differential service (DiffServ) in a layer concept. Manage LSPs efficiently

In addition, when moving from a wired network to a wireless network or when there is a conversion from a wireless network to a wired network, mapping between traffic must be performed in advance. Examples of mappings for the eight flow types in the four AC and HCCA of EDCA provided in 802.11e and the eight traffic types provided in the DiffServ are shown in the following table. Same as 3.

802.11e DiffServ (DSCP) Example Service HCCA NCT RIP, OSPF HCCA EF VoIP HCCA AF4 Video conference EDCA / AC_VI AF3 Termianl Session EDCA / AC_VO AF2 Database Access, Web EDCA / AC_BE AF1 FTP, E-Mail EDCA / AC_BK BE Best effort

Referring to Table 3, three HCCAs of IEEE 802.11e are mapped to NCT, EF, and AF4 of differential network DSCP, AC_VI of EDCA is AF3, AC_VO of EDCA, AF2, AC_BE of EDCA, and AC_BK of EDCA. You can see that it is mapped to BE.

As such, quality assurance between end-to-end should be achieved in both wired and wireless integrated environments. In order to guarantee this quality, it must be able to identify the correct subscribers, establish connection between subscribers, and allocate resources required by subscribers. It provides quality assurance service using DiffServ-over-MPLS network in wired environment, and quality assurance service using 802.11e in wireless environment, and connection establishment using SIP / SDP signaling (Signaling) to establish connection between subscribers. The required service characteristic information is exchanged.

After the QoS setting is completed for the backbone (316) network, the INVITE message is transmitted to the QSTA-B 313 of the second WLAN 210b. The QSTA-B 313 checks the transferred SDP message and allocates an access point (QAP) 317 of the second WLAN 210b and wireless network resources. After allocating the resource with the QAP 317, the QSTA-B 313 prepares the QoS session establishment result as shown in Table 4 below, and sends the QSTA-317 to the QSTA-A 301 through the 180 Ringing / SDP2 message (308).

SDP Property Explanation m = video 23422 RTP / AVP 31 Media information a = rtpmap: 31 H261 / 9000 Media attribute for codec a = curr: qos local sendrecv Media attribute for QoS a = curr: qos remote semdrecv a = des: qos mandatory local sendrecv a = des: qos mandatory remote sendrecv

Referring to Table 4, media information for m = video 23422 RTP / AVP 31 and media attributes for codecs, attributes for quality of service such as a = curr: qos ~ and a = des: qos ~, are displayed. According to Table 4, it can be seen that the QoS setting for the remote is completed, such as "a = curr: qos mandatory remote sendrecv".

Subsequently, the QSTA-A 301 that has received the 180 Ringing / SDP2 message knows that all procedures related to the overall QoS configuration have been completed, and executes a finishing procedure regarding the QoS configuration. That is, when the QSTA-A 301 transmits a PRACK message to the QSTA-B 313 (309), the QSTA-B 313 sends a 200 OK (PRACK) message and a 200 OK (INVITE) message in response thereto. The multimedia session with QoS is completed by transmitting (310,311).

Although the present invention has been described in detail through specific embodiments, the present invention is not limited to the above-described embodiments, and various changes may be made by those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention. It may be changed and implemented.

As described above, according to the present invention, a class for quality of service is mapped between a wireless LAN according to IEEE 802.11e and a Diffserv-over-MPLS network, and a multimedia session is established using SIP / SDP. By setting it up, it is possible to provide end-to-end quality of service even in an integrated wired and wireless environment.

Claims (4)

The calling terminal is connected to the first wireless LAN, the called terminal is connected to the second wireless LAN, and the first wireless LAN and the second wireless LAN provide an differential service through an MPLS backbone network. In the connected wired and wireless integrated network, A first step of the originating terminal allocating a radio network resource according to an access point and a traffic specification of the first WLAN; When the wireless network resource is allocated between the originating terminal and the access point by the first step, the QoS information of the originating terminal is described in the SDP to use an INVITE message. Transmitting to an SIP proxy server; The SIP proxy server may select a preconfigured label switching path (LSP) based on a source address and a destination address, and map traffic between terminals to a selected label switching path (LSP); A fourth step of delivering an invite message to the called terminal after setting the quality of service (QoS) for the MPLS backbone network; A fifth step of checking, by the destination terminal, an SDP message transmitted and allocating an access point and a radio network resource of the second WLAN; A sixth step of, after the allocation of the radio network resources in the second WLAN, the terminating terminal prepares a session establishment result as an SDP and transmits a ringing message to the calling terminal; And And providing a quality of service using SIP and SDP between end terminals in the wired / wireless integrated network. The method of claim 1, wherein the third step  When receiving the SDP describing the quality of service (QoS) information, the SDP (SDP) information is passed to the Q-SIP module, the Q-SIP module of the wireless network A method of providing quality of service using SIP and SDP between end points in a wired / wireless integrated network characterized by mapping a quality of service class to a quality of service class of a wired network. The method of claim 2, wherein the class mapping is Three HCCAs in the WLAN map with NCT, EF, and AF4 in the differential network DSCP, AC_VI in EDCA, AF_VO in AFCA, AF2 in AFCA, AC_BE in EDCA, and AF_B in EDCA, and BE in ACCA. How to provide quality of service by using SIP and SDP in end-to-end wired / wireless converged network. The method of claim 1, wherein the second stage SDP and the sixth stage SDP A method of providing quality of service using SIP and SDP between end points in a wired / wireless converged network characterized by describing media attributes for media information and codec and attributes for quality of service.

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