KR100450512B1 - Method of Multiplexing Transport Paths in the Packet Network Based Network Element - Google Patents

Abstract

The present invention relates to a method for multiplexing transmission paths of a packet network-based network element by implementing a path multiplexing adaptation layer on a transport layer of a packet network-based network element to multiplex a control message transmission path to different packet-based communication networks.

The present invention provides a process for implementing a path multiplexing adaptation layer for delivery path multiplexing between a transport layer and an application layer; Transmitting a multicast forwarding address of the multicast forwarding address to a counterpart network element according to priority and requesting a multipath forwarding connection; Initiating a connection establishment of a multi-transmission path between the network elements by receiving a multi-transmission address of a partner network element; By providing at least one transmission path according to the priority of the multiple transmission path initialized as the control message transmission path to provide a transmission path multiplexing method of a packet network-based network element comprising the step of transmitting a control message to the other network element. In addition, it is possible to provide reliable communication even in the event of a failure of any one of the packet networks, and stable network operation is possible by sharing the load among the multiplexed transmission paths.

Description

Method of Multiplexing Transport Paths in the Packet Network Based Network Element}

The present invention relates to a forwarding path of a packet network-based network element. In particular, the present invention relates to a packet network-based network that enables multiplexing of transmission paths of control messages to different packet-based communication networks by implementing a path multiplexing adaptation layer above the transport layer of the network element. A method for multiplexing the propagation paths of elements.

In general, in the next-generation communication network for voice and high-speed data communication, heterogeneous networks interwork with each other based on a packet network such as an Internet Protocol (IP) network or an Asynchronous Transfer Mode (ATM) network. Provided a function of connecting a packet network and a Public Switched Telephone Network (ISDN) network or an Integrated Services Digital Network (ISDN) network, and recently, as shown in FIG. Gateway and the MGC (Media Gateway Controller) which controls each MG to perform a series of call processing control functions are implemented to implement an open communication system, a next-generation communication network that allows heterogeneous networks to interoperate.

Here, MG is a gateway that manages an interface with each network. In FIG. 1, RGW (Residential GateWay), AGW (Access GateWay), and TGW (Trunk GateWay) may be referred to as MG. In this case, RGW is a subscriber of a PSTN network. A device that terminates analog lines directly. AGW is a device that terminates devices before PSTN exchanges such as Private Branch eXchange (PBX) or subscriber multiplexing equipment. TGW terminates trunk lines of local exchanges in PSTN or N-ISDN networks. Device.

In addition, MGC, an open call agent, is a protocol for transmitting control messages with other network elements, such as Stream Control Transmission Protocol (SCTP), User Datagram Protocol (UDP), Transmission Control Protocol (TCP), and Service Specific Connection (SSCOP). Oriented Protocol, etc., where SCTP provides a multi-home service to support the redundancy of transport paths when interworking with other network elements, but is not currently generalized. As it provides only a single transmission path, it cannot provide services in case of communication network failure.

Meanwhile, in the case of network elements based on the packet network as well as the network elements of the next-generation communication network described above, TCP or UDP protocol is used as a transport layer protocol for delivering control messages with other network elements. As only the path is provided, there is a problem that a service cannot be provided in case of a packet network failure currently connected.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object thereof is to implement a multiplex path adaptation layer between an application layer and a transport layer of a packet network-based network element and to multiplex the transmission path of a control message to any one packet network. In the event of a failure, reliable communication services can be provided, and the load can be shared among multiplexed transmission paths to enable stable network operation.

1 is a schematic configuration diagram of an open switching system which is a general next generation communication network.

2 is a diagram illustrating a layer-by-layer protocol structure of a network element based on a packet network.

3 is a diagram illustrating a transmission path multiplexing structure of a packet network based network element according to the present invention.

4 is a diagram illustrating an example of implementing an MHA layer in a packet network based network element according to the present invention;

5 is an operation flowchart for implementing a method for multiplexing a transmission path of a packet network-based network element according to the present invention.

6 is a diagram illustrating an MHA message structure defined for establishing and managing multiple delivery paths in an MHA layer according to the present invention.

7 is a diagram illustrating a setup message structure for establishing multiple delivery paths in an MHA layer according to the present invention.

8 illustrates a control message structure used in the MHA layer according to the present invention.

9 illustrates a failover message structure for replacing a primary delivery path in an MHA layer according to the present invention.

10 is a diagram illustrating a multi-transport address transmission state according to a transport layer protocol in a packet network based network element of the present invention.

A feature according to an embodiment of the present invention for achieving the above object comprises the steps of: implementing a path multiplexing adaptation layer for delivery path multiplexing between a transport layer and an application layer; Transmitting a multicast forwarding address of the multicast forwarding address to a counterpart network element according to priority and requesting a multipath forwarding connection; Initiating a connection establishment of a multi-transmission path between the network elements by receiving a multi-transmission address of a partner network element; It provides a method for multiplexing transmission paths of a packet network-based network element comprising setting at least one transmission path as a control message transmission path according to the priority of the multiple transmission paths initialized above, and transmitting a control message to a partner network element. have.

In addition, the above-described transmission path multiplexing method of a packet network-based network element, when the path multiplexing adaptation layer initializes the connection setting for the multiple forwarding path, and then transfers the control message currently set when the higher application layer requests the replacement of the primary forwarding path. The method may further include replacing the path with another multi-transmission path.

In addition, the above-described transmission path multiplexing method of a packet network-based network element includes: checking whether a failure occurs in a multiple transmission path between network elements in the path multiplexing adaptation layer; When a failure occurs in the control message transmission path, a control message transmission path is replaced with a control message transmission path by replacing a non-failure multiple transmission path, or a control message transmission path is transmitted to the other network element through the remaining control message transmission path without failure. The method may further include sharing and transmitting the control message.

In this case, the control message transmission path is replaced with the address information on the control message transmission path to be replaced in a failover message, and then transmitted to the other network element. It is done.

On the other hand, the process of requesting the multi-path forward connection, in the case of instructing the multi-path forwarding configuration initialization with the other network element to the path multiplexing adaptation layer using the multi-path forwarding request primitive in the application layer of the network element It is characterized by performing.

Further, the process of requesting the multiple forwarding path connection may include transmitting a multiple forwarding address including forwarding addresses via different communication networks in a path multiplexing adaptation layer to a counterpart network element through a predefined address using a setup message. Requesting multiple forward path connections; And transmitting, as a setup response, its own multiple forwarding address for each forwarding address via the different communication networks received at the multiple forwarding path connection request in the opposite path multiplexing adaptation layer.

In this case, the step of requesting the multi-transmission path connection by using the setup message, after assigning the identification number and priority to each of the multiple forwarding address, the corresponding multi-transmission address with the identification number in the setup message to the priority According to the present invention, it transmits to the other network element in order and requests multiple transmission path connection.

In the requesting of the multiple forwarding path connection, if the communication network serving as the forwarding path with the counterpart network element is an IP-based packet network, the multipath forwarding connection is transmitted by transmitting an IP address and a port number to the multiforwarding address. In the case of an ATM-based packet network, an ATM address is transmitted to a multiple forwarding address, thereby requesting a multipath forward connection.

In the transmitting of the multiple forwarding address of the multicast address as a setup response in the opposite path multiplexing adaptation layer, the multipath forwarding address corresponding to the multicast forwarding address requested by the network element is set up with each identification number. The message is transmitted to the network element at the same priority as the message.

On the other hand, the process of determining whether a failure occurs in the multi-transmission path, by exchanging a packet message for the connection status check through the set multi-transmission path, or by detecting a disconnection or hardware failure of the lower transport layer failure of the multi-transmission path It is characterized by checking whether it occurs.

Here, the connection state check packet message is characterized in that the heartbeat message does not have a separate parameter.

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

In the present invention, a multi-home adaptation protocol is added between a transport layer protocol (UDP, TCP, etc.) and an application layer of a packet network-based network element, and the transmission path is multiplexed. Referring to the protocol for each layer of the network element to be described, as shown in Figure 2, the upper application layer (Application Layer) consists of a transport layer, the Internet layer and a network access layer.

The application layer is a layer that provides network utilities or applications supported by network elements. The transport layer is a layer that provides a connection between network elements and handles data transfer. It is composed of TCP protocol and UDP protocol.

The Internet layer performs IP routing and routing of IP packets between network elements using a dataless method, which is a connectionless service. The network access layer provides a subnetwork function that is responsible for the physical delivery of IP packets.

The transmission path multiplexing structure of the packet network-based network element having such a protocol layer will be described below with reference to the example illustrated in FIG. 3.

First, assuming that different network A and B exist between packet network-based network elements X and Y, each network element X and Y transmits UDP / IP to provide multiple forwarding paths through network A and B. It includes a layer protocol and a path multiplexing adaptation protocol (MHA) layer that performs main path setting and path error monitoring between application layers of user X or Y. In this case, as shown in FIG. 4, the application layer may use the multiple delivery paths A through the MHA layer, and may use only a single delivery path B in association with the direct delivery layer.

That is, the MHA layer establishes or releases a multi propagation path with a power station and checks whether communication is normal on the set path. An operation of setting and managing the same, that is, a method of multiplexing a transmission path of a packet network-based network element, will be described with reference to FIG. 5.

First, in order to set up and manage the multiple delivery paths in the above-described MHA layer, it is necessary to define an MHA message as shown in FIG. Implemented using layer headers.

That is, the MHA message has a structure including a transport layer header, header length information, message type (type) information, parameter tag and length information, and actual parameter data, and as a message type, a setup message for establishing a multiple delivery path. (MH_SETUP, MH_SETUP_ACK), heartbeat messages (MH_HEARTBEAT, MH_HEARTBEAT_ACK) to monitor the status of multiple delivery paths, and failover messages (MH_FAILOVER, MH_FAILOVER_ACK) and control messages to notify the large station of the replacement of the main delivery path. There is a user data message (MH_USER_DATA).

With this MHA message defined, the MHA layer of network element X and the MHA layer of network element Y, acting as a master / slave, establish and manage multiple delivery paths. First, in the application layer of the network element X, which is a master in charge of establishing and replacing the multipathing paths, the MHA layer instructs the MHA layer to initialize the multipathing path establishment with the network element Y by using the multipathing request request primitive. (Step S51).

Then, the MHA layer of network element X transmits its own multiple forwarding addresses (X1, X2) to the other network element Y corresponding to the slave and a predefined address through the transport layer to request a multipath forward connection (step). S52), in this case, after assigning an identification number and priority to each of the forwarding address X1 via the communication network A serving as the multiple forwarding path and the forwarding address X2 via the communication network B, the attached drawing of FIG. By using the MHA setup message (MH_SETUP), such as the corresponding multiple forwarding address (X1, X2) is transmitted to the other network element Y in order according to the priority with its identification number.

Accordingly, the MHA layer of the network element Y corresponding to the slave transmits its own multiple forwarding addresses (X1: Y1, X2: Y2) in response to the multipath forward connection request from the network element X. In this case, the network element A The MHA setup response message shown in FIG. 7B shows a forwarding address (Y1, Y2) via the network A and the network B, which are the forwarding addresses corresponding to the forwarding addresses (X1, X2) requested by the MHA layer of FIG. MH_SETUP_ACK), but similar to the MHA layer of network element X, which is a master, corresponding multiple forwarding addresses (Y1, Y2) are transmitted together with their identification numbers with the same priority.

Here, the MHA setup message and the MHA setup response message shown in (a) and (b) of FIG. 7 described above have a plurality of address parameters for transmitting multiple forwarding address information to the counterpart, for example, network element X. In transmitting the MHA setup message from the MHA layer to network element Y, the forwarding address (X1) via network A has a higher priority than the forwarding address (X2) via network B. In this case, X2 addresses are recorded and transmitted in 'Address Data 2'.In response, the MHA layer of Network Element Y transmits an MHA setup response message to Network Element X. Y1 address, which is a forwarding address, and Y2 address, which is a forwarding address via communication B, are recorded and transmitted to 'address data 2', respectively.

The multi-delivery address information carried on the above-described address parameter 'address data 1' or 'address data 2' becomes an IP address (or port number) when the transport layer protocol is based on UDP or TCP protocol. In the case of other transport layer protocols, the address format will change accordingly.

On the other hand, in the MHA layer of the network element X corresponding to the master, the MHA layer of the network element Y corresponding to the slave receives the multiple forwarding addresses through the MHA setup response message for connecting the multi-path forward from the MHA layer of the network element Y side of the slave. The connection setting for the multi-transmission path of the multi-transmission path A via the communication network A and the multi-transmission path B via the communication network B between the elements Y is initialized (step S53).

Then, after initializing the connection setting for the multiple forwarding paths, one of the multiple forwarding paths is set as the main forwarding path (step S54), and the main forwarding path is the network element X for establishing the connection for the multiple forwarding paths. The forwarding address with the highest priority among forwarding addresses exchanged between network element Y and Y is set as the main forwarding path.

At this time, the network element X and the network element Y store and manage the partner forwarding addresses exchanged when establishing a connection for the multiple forwarding paths together with an identification number in an internal memory, and also store the main forwarding path previously set.

Subsequently, the MHA layer of network element X selects the main delivery path previously set through the transport layer and transmits a control message to network element Y. In this case, the user attaches to the MHA layer using a delivery request primitive. The control message (MH_USER_DATA), which is a user message, is transmitted to the network element Y, but the control message is transmitted using the same primitive on the transport layer protocol. For example, if the UDP protocol is used as a forwarding layer protocol, when the counterpart's representative IP address, port number, and user message are forwarded to the MHA layer, the MHA layer selects a primary forwarding path corresponding to the representative IP address to control messages. Will be sent. That is, a user transmits a control message to a counterpart using a UDP primitive regardless of a delivery path of an MHA layer.

In addition, the MHA layer of the network element X transmits a control message to the network element Y side, and periodically or randomly checks the connection state of the multi-transmission paths A and B to check whether a failure occurs in the main transmission path (step). S55), this is confirmed by checking whether the response message is received after transmitting the heartbeat message having no separate parameter in the network element X to the network element Y side, and if there is no response more than a predetermined number of times, It is determined that the failure has occurred.

In addition, the connection status is checked not only for the main propagation path but also for other multi-transmission paths. The method for checking the connection status of the multi-transmission path is a method for checking the connection status in addition to using the above-described heartbeat message. A check may be performed by exchanging an Alive Packet Message or by detecting a disconnection of a lower transport layer or a hardware failure.

On the other hand, if it is determined in step S55 that the main delivery path has failed, the current main delivery path, that is, the alternative multi-transmission path without failure has been replaced with the main delivery path instead of the current multi-transmission path (step S56). In this case, the MHA layer of the network element X corresponding to the master transmits address information about the newly replaced main transport path to the MHA layer of the network element Y corresponding to the slave when the main forwarding path is replaced. It will replace the main transfer path between Y.

That is, in the MHA layer of network element X, if it is determined that a failure occurs in the main delivery path that is currently in use, the MHA layer of the network element X uses the MHA failover message (MH_FAILOVER) as shown in FIG. The address information is transmitted to the MHA layer of network element Y. In this case, priority is given to the identification number, which is the address information of the main forwarding path to be replaced, and the priority of other alternative multipathing paths is transmitted. The rank is also newly assigned and transmitted.

The MHA layer of network element Y notified of the replacement of the primary delivery path transmits a failover response message (MH_FAILOVER_ACK) as shown in (b) of FIG. 9 to replace the primary delivery path between network elements X and Y. Is complete.

Here, the failover message and the failover response message shown in (a) and (b) of FIG. 9 described above are used to transmit an identification number, which is address information on a main transmission path to be newly replaced, to the counterpart according to its priority. It has a number of identification number parameters, for example in the transmission of a failover message from the MHA layer of network element X to network element Y, a failure occurs in a specific primary forwarding path and a new primary address (X1) via network A. If you want to replace it with a forwarding path, the first 'identification number' field contains 'X1', which is the identification number for the forwarding path via network A, and the next 'identification number' field, via network B with the following priority: Each identification number 'X2' of the transmission path is recorded and transmitted. In response, the MHA layer of network element Y transmits a failover response message to network element X. In the first 'identification number' field, 'Y1', which is the identification number for the transmission path via network A, and in the next 'identification number' field, the identification of the transmission path through network B with the following priority: Each number 'Y2' is recorded and transmitted.

In addition, the operation of replacing the above-described main delivery path may also be replaced at the request of a higher application layer in addition to the case where a failure occurs in the main delivery path currently in use.

On the other hand, in the process of requesting the multi-transport path connection from the MHA layer of the network element X to the MHA layer of the network element Y side through the transport layer, the transport layer uses UDP or IP protocol in the corresponding MHA layer, that is, In the case where the communication network is an IP-based packet network, as shown in FIG. 10 (a), the IP address and port number are transmitted to the multi-forwarding address, and when the transport layer uses the SSCOP protocol, that is, the communication network is ATM-based. In case of the packet network of FIG. 10, the interface / VPI / VCI (Virtual Path Identifier / Virtual Channel Identifier), which is an ATM address, is transmitted to the multicast address.

In addition, in another embodiment according to the present invention, after initializing the multiple forwarding path connection, the control message transmission load may be distributed to the multiplexed forwarding path without setting the main forwarding path, thereby enabling more stable network operation. By checking the connection status of each multiple transmission path and causing a failure in one of the multiple transmission paths, the transport layer transmits a control message through the other multiple transmission paths, thereby enabling stable network operation.

Further, the embodiment according to the present invention is limited to the implementation of the transmission path in the packet network-based network element by redundancy, which is not limited to the above-described embodiment, if the person having ordinary knowledge in the technical field to which the present invention belongs It will be appreciated that the present invention may be practiced in various ways. Therefore, changes of the embodiments of the present invention will not be able to escape the technical scope of the present invention.

The present invention implements a path multiplexing adaptation layer between an application layer and a transport layer of a packet network-based network element to multiplex the transmission path of a control message, thereby providing reliable communication in the event of a failure in any one packet network. In addition, stable network operation is possible by sharing the load among the multiplexed transmission paths.

Claims (11)

Implementing a path multiplexing adaptation layer for delivery path multiplexing between the transport layer and the application layer; Transmitting a multicast forwarding address of the multicast forwarding address to a counterpart network element according to priority and requesting a multipath forwarding connection; Initiating a connection establishment of a multi-transmission path between the network elements by receiving a multi-transmission address of a partner network element; Transmitting at least one transmission path according to the priority of the multiple transmission paths initialized as a control message transmission path, and transmitting a control message to a partner network element. Way. The method of claim 1, After the connection establishment for the multiple forwarding paths is initialized in the path multiplexing adaptation layer, replacing the currently set control message forwarding path with another multi forwarding path when the upper application layer requires replacement of the main forwarding path. A method of multiplexing forwarding paths of packet network based network elements. The method of claim 1, Confirming whether a failure occurs in a multiple transmission path between network elements in the path multiplexing adaptation layer; When a failure occurs in the control message transmission path, a control message transmission path is replaced with a control message transmission path by replacing a non-failure multiple transmission path, or a control message transmission path is transmitted to the other network element through the remaining control message transmission path without failure. A method for multiplexing a transmission path of a packet network-based network element, further comprising: sharing and transmitting a control message. The method of claim 2 or 3, The replacement of the control message transmission path may include receiving address information on a control message transmission path to be replaced in a failover message and transmitting the message to the counterpart network element, and receiving and replacing a failover response message from the counterpart network element. A method of multiplexing forwarding paths of packet network based network elements. The method of claim 1, The requesting of the multipathing path connection may be performed when an application layer of a network element instructs the multipathing adaptation layer to initialize the multipathing path establishment with the other network element using a multipathing path establishment request primitive. A method of multiplexing forwarding paths of packet network based network elements. The method of claim 1, The multi-transmission path connection request may include multi-transmission by transmitting a multi-transmission address including forwarding addresses via different communication networks in a path multiplexing adaptation layer to a counterpart network element through a predefined address using a setup message. Requesting a path connection; A packet network-based network, comprising transmitting, as a setup response, its own multiple forwarding addresses for respective forwarding addresses via the different communication networks received at the request of the multiple forwarding path connection in the opposite path multiplexing adaptation layer. How to multiplex the propagation path of elements. The method of claim 6, The requesting of the multiple forwarding path connection using the setup message may include assigning an identification number and a priority to each of the multiple forwarding addresses, and then inserting the corresponding multiple forwarding addresses in the setup message along with the identification number in order of priority. A transmission path multiplexing method of a packet network-based network element, characterized in that the transmission to the other network element as required to request multiple transmission path connection. The method of claim 6, In the requesting of the multi-path forwarding connection, when the communication network serving as a forwarding path with the other network element is an IP-based packet network, the multi-path forwarding connection is requested by transmitting an IP address and a port number to the multi-forwarding address. In the case of a packet network, a transmission path multiplexing method of a packet network-based network element, characterized by requesting a multipathing path connection by transmitting an ATM address to a multicasting address. The method of claim 6, The transmitting of the multiple forwarding address of the multipath forwarding address as a setup response in the opposite path multiplexing adaptation layer may include the multipath forwarding address corresponding to the multiport forwarding address requested by the network element in the setup response message. The transmission path multiplexing method of a packet network-based network element, characterized in that the transmission to the network element at the same priority. The method of claim 3, wherein The process of determining whether a failure occurs in the multi-transmission path may include: exchanging a packet message for checking a connection state through a set multi-transmission path, or detecting disconnection or hardware failure of a lower forwarding layer to determine whether the multi-transmission path has failed. A method for multiplexing forwarding paths of packet network-based network elements, characterized in that. The method of claim 10, The connection state check packet message is a transmission path multiplexing method of a packet network based network element, characterized in that the heartbeat message does not have a separate parameter.