KR100411596B1 - ATM Based MPLS-LER System and Method for Setting Connection thereof - Google Patents

Abstract

According to the present invention, in the ATM-based MPLS-LER system, in the connection setup for IP / MPLS packet transmission, a matching structure of the FE and the connection according to the system can reduce the number of connections in the system required to transmit the corresponding IP / MPLS packet. It is about setting method.

In the present invention, in performing connection setup for IP / MPLS packet transmission in an ATM-based MPLS-LER system, the connection setup for an additional IP device or LSP can be used by sharing the connection by using a preset internal connection. In this way, the required number of connections inside the switch is limited to the required number of connections, so that no additional connection is required internally in the system, so that all connections can be provided as much as LIM provides, and the total number of connections is required in the related art. The maintenance of the connection can be simplified because the number of FEs is reduced compared to the connection.In addition to the pre-configured connection, the FE stage must be limited when setting up a connection for a newly added IP device or LSP. Connection setup is simple and quick.

Description

AMT-based MPLS-LER system and method for setting connection

The present invention relates to an ATM-based MPLS-LER system and a connection establishment method thereof. In particular, the present invention relates to an ATM-based MPLS-LER system and a method for establishing a connection for transmitting IP / MPLS packets in an ATM-based MPLS-LER system. The present invention relates to a matching structure of a FE so that the number of connections can be reduced, and a connection setting method accordingly.

In general, in order to use the LER in an ATM-based MPLS network, a software function and a hardware function must be added to the conventional ATM switch system.

This software requires various IP / MPLS control software such as Transmission Control Protocol (TCP) / IP, Routing Protocol, MPLS Signaling Protocol, etc. A processor board capable of mounting software, an FE board capable of performing IP / MPLS packet processing, and a MG (Merging) board for preventing the mixing of ATM cells are required.

As shown in FIG. 1, an ATM-based MPLS system serving as a conventional LER has a plurality of IP-side LIMs 11-1 and 11-2 and a plurality of IP-side FEs 12-1 and 12-2. And a plurality of IP side MGs 13-1 and 13-2, an ATM control board 14, an IP / MPLS control board 15, a switch fabric 16, and a plurality of LSR side FEs 17-. 1, 17-2, a plurality of LSR side MGs 18-1, 18-2, and a plurality of LSR side LIMs 19-1, 19-2. Here, the FE (12-1, 12-2, 17-1, 17-2) and the IP / MPLS control board 15 is a module added for the IP or MPLS, the remaining modules are the structure of the general ATM switch I just use it.

The LIMs 11-1, 11-2, 19-1, and 19-2 are boards for processing ATM traffic, including input / output ports, and matching functions with external links or lines. Perform.

The FEs 12-1, 12-2, 17-1, and 17-2 are blocks that perform a Layer 3 Forwarding function to transmit IP or MPLS packets to a corresponding destination. It includes a segmentation and reassembly (SAR) function to assemble and form a layer 3 packet, and to transmit the layer 3 packet again in the form of an ATM cell, and is usually mounted at an input terminal.

The MGs 13-1, 13-2, 18-1, and 18-2 have ATM cells transmitted from the respective FEs 12-1, 12-2, 17-1, and 17-2. Blocks to solve cell interleaving problems that can occur when transmitted over the same ATM connection when transmitted over 16) are usually mounted at the output stage.

The ATM control board 14 is a block in which software related to call processing, maintenance, billing, statistics, etc. is performed in relation to an ATM cell.

The IP / MPLS control board 15 is a block for performing a LER control function by mounting various software including a TCP / IP protocol stack, a routing and signaling protocol for routing information management, and a label switched path. It handles LDP (Label Distribution Protocol) for control and GSMP (General Switch Management Protocol) Master function for switch control according to standard interface.

The switch fabric 16 sends input ATM cells transmitted from the respective FEs 12-1, 12-2, 17-1, and 17-2 to the respective MGs 13-1, 13-2, 18-1, It is a board that transmits by switching to proper output port through 18-2).

An example of a switch connection configuration structure for processing IP / MPLS packets in a conventional ATM-based MPLS-LER system configured as described above is as follows.

First, when connecting to the IP device including a router (Router), as shown in Figure 2 to establish the following connection to transmit and receive IP packets with the IP device connected to the MPLS network.

First, a connection is established so that an IP packet received from an IP device can be transmitted to the IP side FE 12-1 by processing ATM traffic in the IP side LIM 11-1, and the corresponding IP side FE 12-1. After performing the forwarding function in FIG. 2, the connection is established to transmit to the IP / MPLS control board 15 through the switch fabric 16.

Then, the ELL control by the IP / MPLS control board 15 transmits the ATM cell to the IP side MG 13-1 through the switch fabric 16 and the cell at the corresponding IP side MG 13-1. After performing a merging function to prevent mixing, a virtual channel (VC) merging connection that can be transmitted to the IP device through the IP side LIM 11-1 is established.

Then, ATM cells transmitted from all other FEs 12-1, 12-2, 17-1, and 17-2 are received by the IP side MG 13-1 through the switch fabric 16 and the IP is transmitted. After performing a merging function to prevent cell mixing in the side MG 13-1, it sets up a VC merging connection that can be transmitted to the IP device through the IP side LIM 11-1. Connection setup must be performed for all FEs 12-1, 12-2, 17-1, and 17-2.

If you want to attach another IP device to the system, you must set up all the connections as mentioned above for the new IP device. That is, the number of lines that need to be merged equally for all FEs 12-1, 12-2, 17-1, and 17-2 as many as the number of routers connected to the system.

Secondly, when performing a connection for transmitting a control message with the LSR, as shown in FIG. 3, the following connection is established to transmit and receive the LSR, the routing message and the signaling message of the MPLS network.

First, the LSR side LIM 19-1 via the switch fabric 16 via the LSR side MG 18-1 through the switch fabric 16 by LER control by the IP / MPLS control board 15. Set up a connection that can be sent to the LSR.

After performing a forwarding function from the LSR to the LSR side FE 17-1 through the LSR side LIM 19-1, the routing message and the signaling message are performed through the switch fabric 16 through the IP / MPLS control board. Set up the connection to send to (15).

Third, in case of performing the LSP connection for transmitting the MPLS packet, as shown in FIG. 4, the following connection is established to transmit the MPLS packet in the form of ATM cell to the LSR of the MPLS network.

After performing the forwarding function of the MPLS packet in the form of ATM cell in the IP side FE 12-1, it is transmitted to the LSR side MG 18-1 through the switch fabric 16, and the corresponding LSR side MG ( 18-1), after performing a merging function to prevent cell mixing, a connection that can be transmitted to the LSR through the LSR side LIM 19-1 is established, and all FEs installed in the system 1, 12-2, 17-1, 17-2), you need to perform the VC merging connection settings.

Fourthly, when performing the LSP connection for receiving the MPLS packet, as shown in FIG. 5, in order to receive the MPLS packet in the form of ATM cell from the LSR of the MPLS network, the following connection is established.

A connection is established such that an MPLS packet in the form of an ATM cell received from an LSR can be processed by the LSR side LIM 19-1 to process ATM traffic to the LSR side FE 17-1.

As described above, the connection establishment method in an ATM-based MPLS-LER system includes a switch fabric, MG, LIM and IP equipment for all FEs whenever an IP device is attached or one LSP is destined for the MPLS network. Alternatively, merging connections within the system between switch fabrics, MGs, LIMs, and LSRs must be established, so as the number of IP devices or LSPs that need to be connected increases, the number of connections inside the switch needs to be multiplied by the number of FE times the number of connections required. Will increase.

In other words, when establishing a connection for a new IP device or LSP, the internal connection from every FE to the MG board must be set up separately, so that a small increase in the IP device or LSP that needs to be connected will result in too many internal connections. There are many problems that it is very difficult to manage the connection, the case of exceeding the limit of the number of connections of the system.

In order to solve the problems as described above, the present invention in the connection setting for IP / MPLS packet transmission in the ATM-based MPLS-LER system, the number of connections in the system required to transmit the corresponding IP / MPLS packet It is an object of the present invention to provide a matching structure of a FE and a connection establishment method according to the same, so as to reduce the number of FE.

In addition, the present invention is applied to the connection settings for additional IP equipment or LSP by utilizing the internal connection set in advance in the ATM-based MPLS-LER system, so that the connection can be used to share each other, necessary number of connections inside the switch required By limiting the number of connections, there is no need for additional connections internally, so that all connections can be provided as much as the LIM provides, and the total number of connections is reduced by the number of FEs compared to the connections required in the prior art. Its purpose is to simplify maintenance.

In addition, the present invention can be easily and quickly set up by limiting the FE stage at the time of connection setup for newly added IP equipment or LSP in addition to the connection that is basically set in advance in the ATM-based MPLS-LER system There is a purpose.

1 is a block diagram illustrating a conventional Asynchronous Transfer Mode (ATM) based Multi Protocol Label Switching (MPLS) -Label Edge Router (LER) system.

FIG. 2 is a block diagram illustrating a connection establishment structure with an Internet Protocol (IP) device in FIG. 1; FIG.

FIG. 3 is a block diagram illustrating a connection establishment structure for transmitting a control message with a label switching router (LSR) in FIG. 1; FIG.

FIG. 4 is a block diagram illustrating a structure of a label switching path (LSP) connection setting for transmission of an MPLS packet in FIG. 1; FIG.

FIG. 5 is a block diagram illustrating an LSP connection establishment structure for receiving an MPLS packet in FIG. 1; FIG.

6 is a block diagram showing an ATM-based MPLS-LER system according to an embodiment of the present invention.

FIG. 7 is a block diagram illustrating a full mesh connection setting structure between forwarding engines (FEs) in FIG. 6; FIG.

FIG. 8 is a block diagram illustrating a connection establishment structure between an FE and an IP / MPLS control board in FIG. 6; FIG.

FIG. 9 is a block diagram illustrating a connection establishment structure with IP equipment in FIG. 6; FIG.

FIG. 10 is a block diagram illustrating a connection establishment structure for transmitting a control message with an LSR in FIG. 6. FIG.

FIG. 11 is a block diagram illustrating an LSP connection establishment structure for transmitting MPLS packets in FIG. 6; FIG.

FIG. 12 is a block diagram illustrating an LSP connection establishment structure for receiving an MPLS packet in FIG. 6; FIG.

Explanation of symbols on the main parts of the drawings

21-1, 21-2: LIM (Line Interface Module) on IP side

22-1, 22-2: IP side input FE 23-1, 23-2: IP side output FE

24: ATM Control Board

25: IP / MPLS control board 26: Switch Fabric

27-1, 27-2: LSR side input FE 28-1, 28-2: LSR side output FE

29-1, 29-2: LIM side LIM

ATM-based MPLS-LER system according to an embodiment of the present invention for achieving the above object is a plurality of LIM processing the ATM traffic by performing matching with Internet Protocol (IP) equipment or LSR (Label Switching Router) (Line Interface Module); A plurality of input forwarding engines (FEs) which perform a forwarding function and transmit IP or MPLS (Multi Protocol Label Switching) packets received through each LIM to a destination; A switch fabric for switching ATM cells transmitted from each input FE to an appropriate output port; It includes a plurality of output FE to perform a forwarding function to transmit the IP or MPLS packet to the destination through the switch fabric. In this case, the input FE is mounted to an output terminal to perform an IP header or MPLS label lookup function received through each LIM to deliver to the output FE through the switch fabric, and The output FE is mounted to an output terminal and performs an IP header or MPLS label lookup function on an IP or MPLS packet received through the switch fabric to find a destination and transmits an IP or MPLS packet to a corresponding connection.

On the other hand, the connection establishment method of the ATM-based MPLS-LER system according to an embodiment of the present invention for achieving the above object is all mounted on the system in a full mesh structure to transmit the IP / MPLS packet through the switch fabric Presetting a connection between the input and output FEs; A connection for transmitting a control message received through each input FE to an IP / MPLS control board through the switch fabric and transmitting a control message of the corresponding IP / MPLS control board to the respective output FE through the switch fabric in advance Setting process; The connection between the set FE and the connection between the FE and the IP / MPLS control board to establish a connection for the IP / MPLS packet processing by utilizing the connection setting for additional IP equipment or LSP, characterized in that made .

Preferably, the connection setting process for the IP / MPLS packet processing comprises the steps of sharing the connection between the set FE and the connection between the FE and the IP / MPLS control board when connecting to the IP equipment; Establishing a connection for transmitting an IP packet received from the IP device to the IP input FE via an IP side LIM; And establishing a connection for transmitting the IP packet received through the IP side output FE to the IP device via the IP side LIM.

Also preferably, the connection establishment process for processing the IP / MPLS packet may include: sharing and establishing a connection between the configured FE and an IP / MPLS control board when transmitting a control message with an LSR; Establishing a connection for transmitting a control message received through the LSR side output FE to the LSR via an LSR side LIM; And establishing a connection for transmitting the control message received from the LSR to the LSR side input FE via the LSR side LIM.

Further preferably, the connection establishment process for the IP / MPLS packet processing comprises the steps of sharing and establishing the connection between the set FE at the time of LSP connection for MPLS packet transmission; And establishing a connection for transmitting the MPLS packet received from the LSR side output FE to the LSR via the LSR side LIM.

In the present invention, instead of the MG board mounted on the output stage of the ATM-based MPLS-LER system performing the VC merging function, the FE board performing the IP / MPLS packet processing function is mounted on the output stage, whereby the corresponding IP / MPLS packet is stored. When input, the input FE performs an IP Header or MPLS Label Look-up function and passes it to the output FE connected to the Next Hop device, which also receives the IP header or MPLS. It performs the label lookup function to find the destination and sends the corresponding IP / MPLS packet to the connection. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 6, the ATM-based MPLS-LER system according to an embodiment of the present invention includes a plurality of IP-side LIMs 21-1 and 21-2 and a plurality of IP-side input FEs 22-1 and 22. -2), multiple IP side output FEs 23-1, 23-2, ATM control board 24, IP / MPLS control board 25, switch fabric 26, multiple LSRs Side input FEs 27-1, 27-2, a plurality of LSR side outputs FE 28-1, 28-2, and a plurality of LSR side LIMs 29-1, 29-2. .

The LIMs 21-1, 21-2, 29-1, and 29-2 process ATM traffic by performing matching with an IP device or an LSR.

The input FEs 22-1, 22-2, 27-1, and 27-2 perform layer 3 forwarding functions to receive through the LIMs 21-1, 21-2, 29-1, and 29-2. The IP or MPLS packet is transmitted to a corresponding destination, and includes a SAR function for reassembling an ATM cell to configure a layer 3 packet and transmitting the layer 3 packet again in the form of an ATM cell.

The output FEs 23-1, 13-2, 28-1, and 28-2 perform layer 3 forwarding functions to transmit IP or MPLS packets to the corresponding destination through the switch fabric 26. It includes SAR function to reassemble to form a layer 3 packet, and to separate and transmit the layer 3 packet in the form of ATM cell.

The ATM control board 24 performs software related to call processing, maintenance, billing, statistics, etc. in relation to the ATM cell.

The IP / MPLS control board 25 is equipped with various software including a TCP / IP protocol stack, a routing and signaling protocol for routing information management, and performs a LER control function.

The switch fabric 26 sends input ATM cells transmitted from the respective input FEs 22-1, 22-2, 27-1, and 27-2 to each of the output FEs 23-1, 23-2, 28-. 2, 28-2) switch to the appropriate output port for transmission.

An example of a switch connection configuration structure for processing IP / MPLS packets in an ATM-based MPLS-LER system according to an embodiment of the present invention is as follows.

First, in the case of a full mesh connection setup between FE (22-1, 22-2, 23-1, 23-2, 27-1, 27-2, 28-1, 28-2), shown in FIG. As shown in Figure 3, we have a full mesh structure between all input and output FEs 22-1, 22-2, 23-1, 23-2, 27-1, 27-2, 28-1, 28-2 Set up the connection in advance.

After the IP / MPLS packet is forwarded at the input FEs 22-1, 22-2, 27-1, and 27-2, the output FEs 23-1, 23-2, 28 through the switch fabric 26. -1, 28-2) to establish the connection for transmission. At this time, the connection in the full mesh structure set in advance in 'number of FE x number of FE' is used for IP / MPLS packet transmission.

Secondly, establish connection between FE (22-1, 22-2, 23-1, 23-2, 27-1, 27-2, 28-1, 28-2) and IP / MPLS control board 25 In the case of FE (22-1, 22-2, 23-1, 23-2, 27-1, 27-2, 28-1, 28-2) and IP / MPLS control board as shown in FIG. In order to transmit the control message between the 25, that is, the routing message and the signaling message, the following connection is established.

First, a routing message and a signaling message received from the input FEs 22-1, 22-2, 27-1, and 27-2 may be transmitted to the IP / MPLS control board 25 through the switch fabric 26. Set up the connection so that

The FE 23-1, 23-2, 28-1 and 28-2 outputs a routing message and a signaling message through the switch fabric 26 by LER control by the IP / MPLS control board 25. Set up the connection to send to the network. At this time, the connection is utilized to establish a connection for transmitting and receiving control messages between the IP device or LSR.

Third, when connecting to the IP device, as shown in FIG. 9, the following connection is established in order to transmit and receive IP packets with the IP device connected to the MPLS network.

First, the IP packet received from the IP device is set up to connect the IP side LIM 21-1 to process the ATM traffic to the IP side input FE 22-1, and at the same time, the IP side output FE 23 -1) establishes a connection to transmit the IP packet received through the IP side LIM 21-1 to the IP device.

In the first and second cases described above, the preset connection as shown in FIG. 7 and FIG. 8 is shared to be used for the next connection. It demonstrates the use of the connections shown in.

That is, after performing the IP header lookup function in the IP side input FE 22-1, the connection is established to be transmitted to the IP / MPLS control board 25 through the switch fabric 26.

In addition, the LER control by the IP / MPLS control board 25 establishes a connection so that an ATM cell can be transmitted through the switch fabric 26 to the IP output FE 23-1.

In addition, ATM cells transmitted from all other input FEs 22-1, 22-2, 27-1, 27-2 are received through the switch fabric 26 at the IP side output FE 23-1. The IP output FE 23-1 performs an IP header lookup function to establish a connection to find a destination and transmit the corresponding IP packet to the corresponding connection.

Fourth, in case of performing a connection for transmission of a control message with the LSR, as shown in FIG. 10, the following connection is established to transmit and receive the LSR, the routing message, and the signaling message of the MPLS network.

First, a routing message and a signaling message received through the LSR side output FE 28-1 may be established through the LSR side LIM 29-1 to the LSR, and a routing message received from the LSR and A connection capable of transmitting a signaling message to the LSR side input FE 27-1 through the LSR side LIM 29-1 is established.

In the second case described above, the preset connection as shown in FIG. 8 is shared to be used for the next connection. In FIG. 10, a portion shown by a dotted line utilizes the connection shown in FIG. 8. Is showing.

That is, the LER control by the IP / MPLS control board 25 establishes a connection capable of transmitting a routing message and a signaling message to the LSR side output FE 28-1 through the switch fabric 26.

In addition, a connection is established to transmit the routing message and the signaling message received through the LSR side input FE 27-1 to the IP / MPLS control board 25 through the switch fabric 26.

Fifth, when performing the LSP connection for transmitting the MPLS packet, as shown in FIG. 11, in order to transmit the MPLS packet in the form of ATM cell to the LSR of the MPLS network, the following connection is established.

In the first case described above, the preset connection as shown in FIG. 7 is shared and used for the next connection. The dotted line in FIG. 11 shows that the connection shown in FIG. 7 is utilized. have.

That is, the transmission connection from the IP device to the LSR side output FE 28-1 uses a connection established in advance, and merely performs an IP header lookup function at the LSR side output FE 28-1 to find a destination and MPLS. Only one connection that can transmit a packet to the LSR through the LSR side LIM 29-1 needs to be newly established.

Sixth, when performing the LSP connection for receiving the MPLS packet, as shown in Figure 12 to establish the following connection to receive the MPLS packet in the form of ATM cell from the LSR of the MPLS network.

This case is the same as in the prior art, that is, the MPLS packet in the form of an ATM cell received from the LSR can be processed by the LSR side LIM 29-1 to process ATM traffic and transmitted to the LSR side input FE 17-1. Set up the connection so that

As described above, in performing the connection setting for IP / MPLS packet transmission in the ATM-based MPLS-LER system according to the present invention, by applying the internal connection set in advance to the connection setting for the additional IP equipment or LSP to each other By allowing connections to be shared, the required number of connections inside the switch is limited to the number of connections required, so that no additional connections are required internally in the system, so that all connections can be provided as much as LIM provides. The maintenance of the connection can be simplified since it is reduced by the number of times the FE compared to the connection required in the prior art.

In addition, according to the present invention, in addition to the connection that is basically set in advance in the ATM-based MPLS-LER system, by setting the connection for the newly added IP equipment or LSP at the FE stage, it is possible to perform a simple and quick connection setup. Can be.

Claims (7)

A plurality of Line Interface Modules (LIMs) for processing ATM traffic by performing matching with Internet Protocol (IP) equipment or Label Switching Router (LSR); A plurality of input forwarding engines (FEs) which perform a forwarding function and transmit IP or MPLS (Multi Protocol Label Switching) packets received through each LIM to a destination; A switch fabric for switching ATM cells transmitted from each input FE to an appropriate output port; AMT-based MPLS-LS system comprising a plurality of output FE for performing a forwarding function to send an IP or MPLS packet to the destination through the switch fabric. The method of claim 1, The input FE is mounted on an output stage and transmits an IP or MPLS packet received through each LIM to the output FE through the switch fabric by performing an IP header or MPLS label lookup function. LS-LL system. The method of claim 1, The output FE is mounted on an output terminal to perform an IP header or MPLS label lookup function on an IP or MPLS packet received through the switch fabric to find a destination and transmit an IP or MPLS packet to a corresponding connection. Based MPS-LS system. Presetting a connection between all input and output FEs mounted in the system in a full mesh structure to transmit IP / MPLS packets through the switch fabric; A connection for transmitting a control message received through each input FE to an IP / MPLS control board through the switch fabric and transmitting a control message of the corresponding IP / MPLS control board to the respective output FE through the switch fabric in advance Setting process; Characterized in that the connection between the set FE and the connection between the FE and the IP / MPLS control board to establish a connection for IP / MPLS packet processing by utilizing the connection setting for additional IP equipment or LSP A method of establishing a connection of ATM based MPS-LA system. The method of claim 4, wherein The connection setting process for processing the IP / MPLS packet may include setting and sharing the connection between the set FEs and the connection between the FE and the IP / MPLS control board when connecting to an IP device; Establishing a connection for transmitting an IP packet received from the IP device to the IP input FE via an IP side LIM; Setting up a connection for transmitting an IP packet received through the IP-side output FE to the IP device via the IP-side LIM. Way. The method of claim 4, wherein The connection setting process for processing the IP / MPLS packet may include: establishing and sharing a connection between the set FE and the IP / MPLS control board when transmitting a control message to the LSR; Establishing a connection for transmitting a control message received through the LSR side output FE to the LSR via an LSR side LIM; And establishing a connection for transmitting the control message received from the LSR to the LSR input FE via the LSR side LIM. The method of claim 4, wherein The connection establishment process for the IP / MPLS packet processing may include: establishing and sharing a connection between the set FEs at the time of LSP connection for MPLS packet transmission; And establishing a connection for transmitting the MPLS packet received from the LSR side output FE to the LSR via the LSR side LIM.