JP5285019B2 - Optical communication system, communication method, and transfer apparatus - Google Patents

Description

  The present invention relates to an optical communication system configured by a multi-ring redundant communication path in which a plurality of ring-type redundant communication paths are connected by a plurality of shared transfer apparatuses, a communication method therefor, and a transfer apparatus provided therein.

  Currently, a virtual local area network (VLAN) technology is used to identify user communications in a wide area Ethernet (registered trademark) service network of a communication carrier.

  In order to improve the reliability of user communication, ITU-T Recommendation G. As represented by 8032, the use of a ring-type redundant communication path capable of making a path in a telecommunications carrier network redundant and switching a line to protect a user's communication when a failure occurs is progressing. (For example, refer nonpatent literature 3.). Further, a multi-ring redundant communication path having a configuration in which a plurality of ring-type redundant communication paths are connected by a plurality of transfer devices may be used.

  A multi-ring redundant communication path configured with IEEE802.1ad has a path between transfer devices shared by all VLANs belonging to the ring (hereinafter, sometimes referred to as a shared communication path) (for example, non-patent See reference 1.) For this reason, the number of user communications that can be identified is 4094 in total for all ring-type redundant communication paths that share the shared communication path.

  FIG. 1 is an example of a conventional network configuration. A ring-type redundant communication path (RING1, RING2,..., RINGn, n is an integer of 2 or more) exists, and a path connecting the transfer apparatus D and the transfer apparatus E is the shared communication path 13. Each ring-type redundant communication path has at least one blocked port, whereby the communication path between the transfer apparatuses is uniquely maintained. For example, when communication is performed from the transfer device A to the transfer device P in FIG. 1, the signal passes through the route A-F-E-D-L-P in order. Further, when performing communication closed on the ring-type redundant communication path RING2, for example, when performing communication from the transfer apparatus K to the transfer apparatus G, the signal passes through the path KEDG in order. Done. As described above, even if the communication is in the ring type redundant communication path or the communication is across the ring type redundant communication path, it passes through the shared communication path 13 between the transfer device D and the transfer device E.

  On the other hand, in the case of communication from the transfer apparatus J to the transfer apparatus G, the signal passes through the path J-H-G in order, and communication is performed. Therefore, the shared communication path 13 between the transfer apparatus D and the transfer apparatus E is If the path (local communication path 11) between the transfer apparatus J and the transfer apparatus H fails, the blocked port set in the transfer apparatus K is opened by controlling the ring-type redundant communication path. Is changed to a route in the order of JK-E-D-G. In other words, even if the communication is closed in the normal ring-type redundant communication path and does not pass through the shared communication path 13, the shared communication path 13 between the transfer device D and the transfer device E is considered in consideration of the failure. It is necessary to set the VLAN so that communication is possible.

  From the above, in a multi-ring type network configuration, it is necessary to set a VLAN in the shared path, and the number of users that can be identified in the entire network is 4094 in the case of IEEE 802.1ad.

  On the other hand, there is IEEE 802.1ah as a technique for expanding the number of user communications that can be identified, and if this is adopted, the number of user communications that can be identified in a multi-ring redundant communication path can exceed 4094 (for example, , See Non-Patent Document 2.)

IEEE802.1ad Provider Bridges IEEE802.1ah Provider Backbone Bridges ITU-T G. 8032 Ethernet (registered trademark) ring protection switching

  However, in order to completely change the multi-ring redundant communication path configured in IEEE802.1ad to IEEE802.1ah, all the transfer apparatuses constituting the ring-type redundant communication path are transfer apparatuses compatible with IEEE802.1ah. There is a problem that the introduction cost is high.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a communication system, a communication method, and a transfer apparatus capable of expanding the number of user communications that can be identified with a small introduction cost in a multi-ring redundant communication path configured with IEEE 802.1ad. And

  In order to achieve the above object, the present invention performs frame conversion on a signal transferred through a shared communication path in a multi-ring redundant communication path that makes the communication path redundant, and applies to a signal that has passed through the shared communication path. It was decided to return to the original frame format.

  Specifically, the communication system according to the present invention includes a plurality of ring-type redundant communication paths that form a ring with a local communication path that each has and a shared communication path that is shared by all, and the shared communication path at both ends of the shared communication path. Connecting the communication path and the local communication path, and from the user in the ring-type redundant communication path to the other user in the same ring-type redundant communication path or another ring-type redundant communication path, the shared communication path And a transfer device that converts the network identifier format so that the number of users that can be identified during propagation on the shared channel is greater than the number of users that can be identified during propagation on the local channel. .

  The optical communication method according to the present invention includes a plurality of ring-type redundant communication paths that form a ring with a local communication path that each has and a shared communication path that is shared by all, the shared communication path at both ends of the shared communication path, and the A communication method of a communication system comprising: a transfer device that connects a local communication path, wherein a user in the ring-type redundant communication path is in the same ring-type redundant communication path or another ring-type redundant communication path Network identifiers such that the number of users that can be identified during propagation on the shared channel is greater than the number of users that can be identified during propagation on the local channel for signals transferred to other users via the shared channel It is characterized by converting the format.

  The present communication system and its communication method convert a frame network identifier format into an extended network identifier format when a signal is transferred from a local communication channel to a shared communication channel in a multi-ring redundant communication channel. For example, the frame is converted from the IEEE 802.1ad format to the IEEE 802.1ah format. In addition, the communication system and the communication method thereof convert the extended network identifier format of the frame to the network identifier format when the signal is transferred from the shared communication path to the local communication path. For example, the frame is converted from the IEEE 802.1ah format to the IEEE 802.1ad format. As a result, 4094 users can be identified in each ring-type redundant communication channel, and a maximum of 16767959 users can be identified as a whole communication system.

  Therefore, the present invention can provide a communication system and a communication method capable of expanding the number of user communications that can be identified with a small introduction cost in a multi-ring redundant communication path configured with IEEE 802.1ad.

  In the communication system and the communication method according to the present invention, the ring-type redundant communication path can be blocked and connected in a part of the local communication path.

  By having at least one blocked port for each ring-type redundant communication path, a communication path between users can be kept unique.

  In the communication system and the communication method according to the present invention, the transfer device converts the network identifier format by changing a bit length of the network identifier. The number of identifiable network identifiers can be increased by changing the bit length.

  A communication method according to the present invention includes a plurality of ring-type redundant communication paths that form a ring with a local communication path that each has and a shared communication path that is shared by all, and that can be blocked and connected in a part of the local communication path And a transfer device that connects the shared communication path and the local communication path at both ends of the shared communication path, and a communication method of a communication system, the same from the user in the ring-type redundant communication path For signals transferred via the shared communication path to other users in the ring-type redundant communication path or in the other ring-type redundant communication path, at the time of propagation of the local communication path and at the time of propagation of the shared communication path From the first state in which the network identifier format is not converted, the number of users that can be identified at the time of propagation through the shared communication path is larger than the number of users that can be identified at the time of propagation through the local communication path. When switching to the second state for converting the network identifier format, a part of the local communication path blocked in any one of the ring-type redundant communication paths is connected, and the shared communication path side of the transfer device A first step of closing the port, a second step of changing the setting of the transfer device so as to change from the first state to the second state, and opening the port on the shared communication path side of the transfer device closed In addition, a third step of sequentially blocking a part of the local communication path of the ring-type redundant communication path connected in the first step is performed.

  This communication method can increase the number of identifiable user communications in the entire communication system without stopping the service.

  The transfer device according to the present invention includes a local port to which the local communication paths of a plurality of ring-type redundant communication paths that form a ring are formed by a local communication path that each has and a shared communication path that is shared by all, and the shared communication Network so that the number of users identifiable at the time of propagation of the shared communication path is greater than the number of users identifiable at the time of propagation of the local communication path for one shared port to which a path is connected and a signal input from the local port The number of users that can be identified at the time of propagation through the local communication path is less than the number of users that can be identified at the time of propagation through the shared communication path for signals that are converted to an identifier format, output to the shared port, and input from the shared port. The ring-type redundant communication path that converts the network identifier format and includes the signal transfer destination user And a regulating circuit for outputting to the local ports which the local communication path is connected.

  The transfer apparatus is installed in a multi-ring redundant communication path, and converts a frame network identifier format into an extended network identifier format when transferring a signal from a local communication path to a shared communication path. For example, the frame is converted from the IEEE 802.1ad format to the IEEE 802.1ah format. In addition, when transferring a signal from the shared communication path to the local communication path, the transfer apparatus converts the extended network identifier format of the frame into the network identifier format. For example, the frame is converted from the IEEE 802.1ah format to the IEEE 802.1ad format. As a result, 4094 users can be identified in each ring-type redundant communication channel, and a maximum of 16767959 users can be identified as a whole communication system.

  Therefore, the present invention can provide a transfer apparatus capable of expanding the number of user communications that can be identified with a small introduction cost in a multi-ring redundant communication path configured with IEEE802.1ad.

  The adjustment circuit of the transfer device according to the present invention converts the network identifier format by changing a bit length of the network identifier.

  The present invention can provide a communication system, a communication method, and a transfer apparatus that can increase the number of user communications that can be identified with a small introduction cost in a multi-ring redundant communication path configured with IEEE 802.1ad.

It is a conceptual diagram explaining the conventional communication system. It is a conceptual diagram explaining the communication system which concerns on this invention. It is a conversion example of the network identifier in the communication system which concerns on this invention. It is a conceptual diagram explaining the transfer to the communication system which concerns on this invention. It is a conceptual diagram explaining the transfer to the communication system which concerns on this invention. It is a conceptual diagram explaining the transfer to the communication system which concerns on this invention. It is a conceptual diagram explaining the transfer to the communication system which concerns on this invention.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components.

  FIG. 2 is a conceptual diagram illustrating the communication system 301 according to the first embodiment. The communication system 301 includes a plurality of ring-type redundant communication paths (RING1, RING2,..., RINGn) formed by a local communication path 11 and a shared communication path 13 shared by all, and the shared communication path 13. The common communication path 13 and the local communication path 11 are connected at both ends of the network, and shared communication is performed from a user in the ring-type redundant communication path to another user in the same ring-type redundant communication path or another ring-type redundant communication path. A transfer device (E) that converts the network identifier format so that the number of users that can be identified when propagating through the shared communication path 13 is greater than the number of users that can be identified when propagating through the local communication path 11 , D).

  In the communication system 301, a user transmits and receives signals with transfer devices (A to E, F to H, J to L, and Q to R). In addition to the above, the transfer device (E, D) also has a function of connecting a plurality of ring-type redundant communication paths. That is, the transfer device (E, D) is connected to the local ports (D-1 to N, E-1 to N) to which the local communication paths 11 of the plurality of ring-type redundant communication paths are connected to the shared communication path 13. Number of users that can be identified during propagation on the shared communication path 13 for signals input from one shared port (D-sh, E-sh) and local ports (D-1 to N, E-1 to N) The network identifier format is converted so as to be larger than the number of identifiable users at the time of propagation on the local communication path 11, and output to the shared port (D-sh, E-sh), and the shared port (D-sh, E-sh) ), The network identifier format is converted so that the number of users identifiable at the time of propagation through the local communication path 11 is smaller than the number of users identifiable at the time of propagation through the shared communication path 13, and the signal transfer destination Comprising local port (D-1~N, E-1~N) of local communication path 11 of the ring redundant communication path that includes The is connected to the adjusting circuit that outputs to a (not shown), a.

  For example, the transfer device (D, E) converts the network identifier format by changing the bit length of the network identifier. For example, when the local communication path is IEEE 802.1ad, the network identifier is 12 bits long and the number of recognizable users is 4094. When the shared communication path is IEEE802.1ah, the extended network identifier is 24 bits long, and the number of recognizable users is 16777959.

  Ring-type redundant communication paths (RING1, RING2,..., RINGn) can be blocked and connected in a part of the local communication path 11. The communication system 301 blocks a part of the annular communication path by closing the port on the transfer device D side of the transfer device C, the port on the transfer device J side of the transfer measure K, and the port on the transfer device Q side of the transfer device R. It is shut off.

  The communication system 301 includes the transfer device (E, D), and converts a frame into, for example, an IEEE 802.1ah format as an extended network identifier format when transferring a signal to the shared communication path. As a result, the number of users that can be identified for each ring-type redundant communication path is 4094 as in the past, but the entire communication system 301 can identify a maximum of 16767959 users.

  When the communication system 301 performs communication from the transfer apparatus A to the transfer apparatus P, the communication is performed by transferring a signal through an order of A-F-E-D-L-P. Here, when transmitting a signal from the transfer device E to the transfer device D, the transfer device E converts the frame format from the network identifier (IEEE802.11ad format) to the extended network identifier (IEEE802.ah format). Send. When the transfer device D receives this signal, the transfer device D converts the extended network identifier (IEEE 802.1ah format) into a network identifier (IEEE 802.1ad format) and transmits the signal to the transfer device L.

  In addition, when performing communication closed on the ring-type redundant communication path RING2, for example, when performing communication from the transfer apparatus K to the transfer apparatus G, communication is performed by transferring a signal through a path called KEDG. Is called. Also in this case, when transmitting a signal from the transfer device E to the transfer device D, the transfer device E converts the frame format from the network identifier (IEEE802.11ad format) to the extended network identifier (IEEE802.80ah format). Then send. When the transfer device D receives this signal, the transfer device D converts the extended network identifier (IEEE 802.1ah format) into a network identifier (IEEE 802.1ad format) and transmits the signal to the transfer device G.

  FIG. 3 is an example of network identifier conversion performed by the transfer device (D, E). The user α is identified with a VLAN-ID of 100 in the ring-type redundant communication path RING1 and with a VLAN-ID of 300 in the ring-type redundant communication path RINGn. When the user α communicates from the transfer device A to the transfer device P, the transfer device E receives a signal at the port E-1. The transfer apparatus E converts the VLAN-ID100 signal received at the port E-1 into the frame format of the extended network identifier, and transmits the VLAN-ID as 1000 from the port E-sh. Next, the transfer device D converts the signal of the extended network identifier (VLAN-ID1000) received at the port D-sh into the frame format of the network identifier on the ring-type redundant communication path RINGn, and sets the VLAN-ID as 300 to the port. Transmit from DN.

  On the other hand, the user β is identified with a VLAN-ID of 100 in the ring-type redundant communication path RING2. When the user β communicates from the transfer device K to the transfer device G, the transfer device E receives a signal at the port E-2. The transfer apparatus E converts the VLAN-ID100 signal received at the port E-2 into the frame format of the extended network identifier, and transmits the VLAN-ID as 2000 from the port E-sh. Next, the transfer apparatus D converts the frame of the extended network identifier (VLAN-ID 2000) received at the port D-sh into the frame format of the network identifier on the ring-type redundant communication path RING2, and sets the VLAN-ID as 100 to the port. Transmit from D-2.

  As described above, the communication system 301 expands the user α whose VLAN-ID is 100 in the ring-type redundant communication path RING1 and the user β whose VLAN-ID is 100 in the ring-type redundant communication path RING2 in the shared communication path 13. A user is identified by assigning a different VLAN-ID as a network identifier format. Furthermore, when IEEE802.1ah is applied as an extended network identifier, it is possible to identify a maximum of 16777959 users. Therefore, the communication system 301 can identify 4094 users for each ring-type redundant communication path, and the maximum multi-ring as a whole. 16776959 users can be identified.

  Hereinafter, a method of shifting from the communication system 300 in FIG. 1 to the communication system 301 in FIG. 2 in the multi-ring redundant communication path will be described with reference to FIGS.

  In this method, a shared communication path 13 is transmitted from a user in a ring-type redundant communication path (RING1, RING2,..., RINGn) to another user in the same ring-type redundant communication path or another ring-type redundant communication path. For the signal transferred via the local communication path 11 and the propagation of the shared communication path 13 from the first state (FIG. 1) in which the network identifier format is unconverted between the propagation of the local communication path 11 and the propagation of the shared communication path 13 When switching to the second state (FIG. 2) in which the network identifier format is converted so that the number of users that can be identified is larger than the number of users that can be identified at the time of propagation on the local communication path 11, the local area blocked in the ring-type redundant communication path RING1 A first step of connecting a part of the communication path 11 (port on the transfer device D side of the transfer device C) and closing the port D-sh of the transfer device D; The second step of changing the setting of the transfer device D so as to change from the state to the second state, and the closed port D-sh of the transfer device D are opened, and the ring type redundant communication path RING1 connected in the first step The third step of blocking a part of the local communication path 11 (the port on the transfer device D side of the transfer device C) is sequentially performed.

  4 to 5 are conceptual diagrams illustrating the first step. In the first step, the blocked port is moved to the ports (D-sh, E-sh) constituting the shared communication path 13. In this example, the blocked port of the ring-type redundant communication path RING1 is moved from the port of the transfer apparatus C to the shared communication path 13 section between the transfer apparatus D and the transfer apparatus E. When the blocked port is moved to the 13 shared communication paths, only the blocked port in any one ring of the ring type redundant communication paths (RING1 to RINGn) is moved. If the blocked ports in a plurality of ring-type redundant communication paths are moved, for example, the blocked port of the ring-type redundant communication path RING1 and the blocked port of the ring-type redundant communication path RING2 are opened and blocked in the shared communication path 13 section. This is because when the port is set, the communication A-B-C-D-G-H-J-K-E-F-A becomes possible, causing a loop failure.

  In the state of FIG. 4, the communication path from the transfer device A to the transfer device P is A-F-E-DLP, but in the state of FIG. The path is changed to CDLP, and communication from the transfer apparatus A to the transfer apparatus P can be continued.

  5 to 6 are conceptual diagrams for explaining the second step. In the second step, the transfer device (D, E) is changed so that the IEEE 802.1ah frame format can be transmitted / received to / from the ports (D-sh, E-sh) constituting the shared communication path 13. Since the blocked port is moved to the shared communication path 13 section in the first step, and the communication between users communicates through another path, the transfer device (D, E) can be changed without affecting the communication between users. Can be implemented.

  6 to 7 are conceptual diagrams illustrating the third step. In the third step, the position of the blocked port is returned from the port (D-sh, E-sh) constituting the shared communication path 13 to the original position (port of the transfer device C). Thereby, the transition from the communication system 300 to the communication system 301 is completed. By implementing this method, it is possible to increase the number of users that can be accommodated in the communication system without service interruption.

  In the present embodiment, the network identifier format is IEEE 802.1ad and the extended network identifier format is IEEE 802.1ah. However, the present invention is not limited to this example, and any frame format in which the number of network identifiers is expanded is applicable.

11: Local communication path 13: Shared communication path 300, 301: Communication systems A to H, J to L, Q to R: Transfer devices D-1 to N, E-1 to N: Local ports D-0, E- 0: Shared port D-sh, E-sh: Shared port (extended network identifier format supported)
RING1, RING2, ..., RINGn: Ring-type redundant communication path

Claims (2)

A plurality of ring-type redundant communication paths that form a ring with a local communication path that each has and a shared communication path that is shared by all, and that can be blocked and connected in part of the local communication path;
A transfer device that connects the shared communication path and the local communication path at both ends of the shared communication path;
A communication method of a communication system comprising:
For a signal transferred from the user in the ring-type redundant communication path to another user in the same ring-type redundant communication path or another user in the ring-type redundant communication path via the shared communication path, the local From the first state in which the network identifier format is unconverted between the propagation time of the communication channel and the propagation time of the shared channel, the number of users who can be identified at the time of propagation of the shared channel is more than the number of users who can be identified at the time of propagation of the local channel When switching to the second state of converting the network identifier format so as to increase,
A first step of connecting a part of the local communication path blocked in any one of the ring-type redundant communication paths and closing the port on the shared communication path side of the transfer device;
A second step of changing the setting of the transfer device so as to change from the first state to the second state;
A third step of opening a port on the shared communication path side of the transfer device, and blocking a part of the local communication path of the ring-type redundant communication path connected in the first step;
The communication method characterized by performing in order. The communication method according to claim 1, characterized in that converting the network identifier form by changing the bit length of the network identifier.

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