JP2009290405A - Network transmitting device, and control message transfer method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a data communication network using an IP router and an ether switch is constructed for C-Plane apart from an optical transmission network for a D-Plane and separately managed in the conventional GMPLS network. <P>SOLUTION: In the control message transfer method for transferring a GMPLS control message through a link established between network transmitting devices constituting a GMPLS network, a control channel for transmitting a GMPLS control message is formed into a transmission path of a predetermined band formed in the link between the network transmitting devices, monitors a traffic amount of the control channel, and a control channel band is made variable so as to control the band of the control channel into a predetermined ratio of a transmission path band. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control message transfer technique for transferring a GMPLS control message in a GMPLS network, and a network transmission apparatus using the control message transfer technique.

In recent years, with the speeding up of information transmission and the development of optical networks, GMPLS (Generalized MPLS) networks have become widespread. The GMPLS network provides an end-to-end communication infrastructure between network transmission apparatuses using an optical transmission network such as time division multiplexing (TDM) or wavelength multiplexing (WDM). FIG. 7 shows the configuration of a conventional GMPLS network. In FIG. 7, network transmission apparatuses such as node A, node B, and node C are connected to each other through an optical link to form a transmission path, and a D-Plane (data plane) is constructed. On the other hand, it is necessary to transmit a GMPLS control message for performing network information acquisition, path control, and the like between D-Plane network transmission apparatuses, which is different from a GMPLS network such as a DCN (Data Communication Network). A C-Plane (control plane) is configured in the network (for example, see Patent Document 1).
JP 2004-015513 A

  As described above, in the conventional GMPLS network, it is necessary to construct a data communication network using an IP router and an Ethernet switch for C-Plane apart from an optical transmission network for D-Plane. As a result, it is necessary to design a network for C-Plane, to arrange an IP router, an Ethernet switch, etc. based on the designed network, and to perform maintenance management work such as setting these devices. In particular, since the network for C-Plane is a different network from the GMPLS network for D-Plane, the communication carrier must manage two networks for C-Plane and D-Plane separately. There was a problem.

  In view of the above problems, an object of the present invention is to provide a network transmission apparatus and a control message that can easily construct and manage a C-Plane for transmitting a GMPLS control message without constructing another network for C-Plane. It is to provide a transfer method.

  A control message transfer method according to the present invention is a control message transfer method for transferring a GMPLS control message via a link established between network transmission devices constituting a GMPLS network, and is formed on a link between the network transmission devices. A control channel for transmitting a GMPLS control message is formed in the transmission band of the predetermined band, and the traffic amount of the control channel is monitored so that the band of the control channel falls within a predetermined ratio of the transmission path band. The control channel band is variable.

  As a result, a control channel for transmitting the GMPLS control message is formed in the transmission path formed between the network transmission apparatuses of the GMPLS network without constructing another network for the C-Plane, and the C-Plane is set. It can be realized to acquire network information between network transmission devices and perform path control. In particular, the amount of traffic on the control channel is monitored and the control channel bandwidth is controlled so as to be a predetermined ratio with respect to the transmission path band established between the network transmission apparatuses. Control channel bandwidth can be reduced.

  More preferably, the amount of traffic on the control channel is monitored at predetermined time intervals.

  As a result, even when the traffic amount of the control channel changes, it is possible to appropriately control the control channel band so as to be a predetermined ratio with respect to the transmission path band established between the network transmission apparatuses.

  More preferably, if the control channel is not formed when a link is established between the network transmission apparatuses constituting the GMPLS network, a new control channel is formed between the network transmission apparatuses constituting the GMPLS network. If the control channel is already formed when the link is established, a new control channel is not formed.

  As a result, even when a plurality of links are established between the same network transmission devices, the network transmission devices can be controlled in a single control channel.

  The network transmission apparatus according to the present invention is a network transmission apparatus constituting a GMPLS network, wherein link establishment is established for establishing a link between a plurality of SONET / SDH interfaces and adjacent network transmission apparatuses via the plurality of SONET / SDH interfaces. A cross-connect unit for selectively connecting the plurality of SONET / SDH interfaces, a GMPLS protocol processing unit for processing a GMPLS control message, and a control channel for transmitting the GMPLS control message between the network transmission devices. A control channel forming unit formed in a transmission path of a predetermined band formed on the link of the network, and a traffic monitoring the traffic amount of the control channel processed by the cross connect unit. A control channel management unit that manages the control channel bandwidth so that the bandwidth of the control channel falls within a predetermined ratio of the transmission path bandwidth according to the amount of traffic monitored by the traffic monitoring unit, and the control And a control unit that controls transmission path setting so that a control channel band designated by the channel management unit is obtained.

  As a result, a control channel for transmitting the GMPLS control message is formed in the transmission path formed between the network transmission apparatuses of the GMPLS network without constructing another network for the C-Plane, and the C-Plane is set. It can be realized to acquire network information between network transmission devices and perform path control. In particular, the traffic amount of the control channel is monitored by the traffic monitor unit, and is controlled by the control channel management unit and the control unit so that the control channel band becomes a predetermined ratio with respect to the transmission path band established between the network transmission apparatuses. As a result, the control channel bandwidth can always be kept within a predetermined ratio of the total transmission path bandwidth.

  More preferably, the traffic monitor unit monitors the traffic amount of the control channel at predetermined time intervals.

  As a result, even when the traffic amount of the control channel changes, the control channel management unit and the control unit appropriately control the control channel band so that the control channel band becomes a predetermined ratio with respect to the transmission path band established between the network transmission devices. can do.

  More preferably, the control channel forming unit forms a new control channel if the control channel is not formed when a link is established between network transmission apparatuses, and the control channel is already formed. If it is, a new control channel is not formed.

  As a result, even when a plurality of links are established between the same network transmission apparatuses, the control channel management unit can control the network transmission apparatuses in one control channel.

  According to the present invention, the control channel for transmitting the GMPLS control message is formed in the transmission path formed between the network transmission apparatuses without constructing another network for C-Plane. Can be easily constructed and managed. In addition, since the control channel band is varied so that the control channel band becomes a predetermined ratio of the transmission path band according to the traffic amount of the control channel, the control channel band can always be suppressed within the predetermined ratio of the transmission path band. it can.

Hereinafter, embodiments of a network transmission device and a control message transfer method used for a GMPLS network according to the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 shows a configuration example of a GMPLS network using a network transmission apparatus according to the present embodiment. FIG. 1 corresponds to FIG. 7 of the prior art.

  In FIG. 1, network transmission apparatuses such as node A, node B, and node C are connected to each other by optical links. A transmission path for client signals is formed in the optical link extending between the nodes to provide D-Plane, and a transmission path for the control channel for transmitting the GMPLS control message in the same optical link. Is formed to provide C-Plane.

  As described above, the conventional GMPLS network shown in FIG. 7 requires a separate DCN (data communication network) for transmitting the GMPLS control message. In the GMPLS network according to the present embodiment, as shown in FIG. DCN is not required. The GMPLS network is a network that transmits client data with a label added, and each node constitutes a network transmission device such as LSR (Label Switch Router) or LER (Label Edge Router).

  In addition, the GMPLS control message determines the label for identifying the label and forwarding the transmission frame, and RSVP-TE (Resource Reservation Protocol-Traffic Engineering) for reserving the bandwidth of the transmission path, and obtaining the shortest path. It handles control protocols such as OSPF-TE (Open Shortest Path First Traffic Engineering), a control channel for transmitting GMPLS control messages, and link management protocol (LMP) for link management / fault management.

  Next, the transmission path between the network transmission apparatuses of node A, node B, and node C will be described in detail with reference to FIG. In FIG. 2, a bidirectional optical link is established between the nodes. For example, an optical link 101a and an optical link 101b are extended between the node A and the node B, and an optical link 102a and an optical link 102b are extended between the node B and the node C. The node B is connected to client apparatuses A and B such as a gateway connected to the client-side network via optical links 103 and 104. For example, the client data from which the label is removed at the node B is output to the client device A or the client device B, and the client data input from the client device A or the client device B is attached to the node B at the node (push). And forwarded to node A or node C toward the destination.

  For example, as shown in the balloon frame of FIG. 2, the optical link 101 a has an SDH (Synchronous Digital Hierarchy) frame type STM-xx (Synchronous Transport Module -xx) and a SONET (Synchronous OpticalCET type ET). -Yy (optical coupler -yy). A plurality of transmission paths are formed in the optical link 101a. In this embodiment, a control channel transmission path 151 for transmitting a GMPLS control message is formed in addition to the transmission paths 152 to 155 for client signals.

  Here, each transmission path is formed by a virtual container VC (Virtual Container), and a label is added and transmitted to the destination. An example of this is shown in FIG. FIG. 3A shows the configuration of the VC. A client signal and a control message are placed in the payload portion, and a destination label is described in POH (Path Over Head). For example, in FIG. 3A, in the case of the VC3 transmission path, the payload portion of the frame is composed of 84 columns, and in the case of the VC4 transmission path, the payload portion of the frame is composed of 260 columns. Also, virtual containers can be connected. For example, in the case of VC3-4v, a transmission path is formed by virtually connecting four virtual containers of VC3.

  In the case of an SDH optical link, the virtual container formed in this way is mounted on the payload portion of the STM-xx frame and transmitted. An example of an SDH transmission frame is shown in FIG. In FIG. 3 (b), RSOH (Regenerator Section Over Head), MSOH (Multiplex Section Over Head), etc. are used for SDH control, and AUP (Administrative Unit Pointers) is used when multiple virtual containers are installed in the payload part. Pointer indicating the starting point.

  In this way, the control channel transmission path 151 and the client signal transmission paths 152 to 155 for transmitting the GMPLS control message of FIG. 2 are transmitted in the virtual container, and are sent to the destination by the label added to the virtual container. Forwarded. For example, a VC3-4v transmission path is formed as the control channel path in FIG. 2, or a transmission path such as a narrow band VC3-3v or a wide band VC3-5v is formed.

  Next, the configuration of network transmission apparatuses such as node A, node B, and node C will be described in detail. FIG. 4 is a block diagram showing the configuration of the node B. Node A and node C are configured in the same manner as node B.

  In FIG. 4, the node B includes a SONET / SDH interface (IF) 201, a SONET / SDH interface (IF) 202, a LO (low-order line) interface (IF) 203, and a LO (low-order line) interface (IF ) 204, a cross-connect unit 205, a control unit 206, a GMPLS protocol processing unit 207, a traffic monitoring unit 208, and a control channel management unit 209.

  In FIG. 4, the node A is terminated at the SONET / SDHIF 201 of the node B through the optical link 101 and connected to the cross-connect unit 205. Similarly, the node C is terminated at the SONET / SDHIF 202 of the node B through the optical link 102 and connected to the cross-connect unit 205. The client apparatus A is terminated at the LOIF 203 of the node B via the low-order optical link 103 and connected to the cross-connect unit 205. Similarly, the client apparatus B is terminated at the LOIF 204 of the node B through the low-order optical link 104 and connected to the cross-connect unit 205.

  The cross-connect unit 205 refers to the label table obtained from the GMPLS protocol processing unit 207 based on the command of the control unit 206, and according to the labels of the virtual containers input / output from the SONET / SDHIF 201, 202 and LOIF 203, 204. , Switched and forwarded by destination.

  In addition, the control unit 206 establishes a control channel and bandwidth control for transmitting the GMPLS control message. Further, by using information such as RSVP-TE and OSPF-TE obtained from the GMPLS protocol processing unit 207, route designation, bandwidth reservation, and shortest route control are performed.

  The GMPLS protocol processing unit 207 transmits / receives a GMPLS control message to / from the network transmission apparatuses such as the node A and the node C via the cross-connect unit 205 and outputs control information to the control unit 206.

  The traffic monitor unit 208 monitors the traffic amount of the control channel processed by the cross connect unit 205. That is, the bandwidth transmitted through the control channel is measured and output to the control channel management unit 209.

  The control channel management unit 209 determines whether the control channel band is equal to or larger than the band of the entire transmission path including the transmission path of the client signal, and outputs the determination result to the control unit 206. Receiving this, the control unit 206 increases or decreases the control channel band according to the determination result. Next, bandwidth control of the transmission path will be described.

  FIG. 5 is a flowchart showing control channel construction processing. Note that the flowchart of FIG. 5 is processed centering on the control unit 206 of FIG.

  (Step S101) A control channel construction process is started.

  (Step S102) It is determined whether or not there is an established link between opposing nodes. When there is an established link, the process proceeds to step S103, and when there is no established link, the process proceeds to step S108 and the process ends.

  (Step S103) It is determined whether or not a control channel has been established between nodes having established links. If there is no established control channel, the process proceeds to step S104. If there is an established control channel, the process proceeds to step S108 and the process is terminated.

  (Step S104) A VC path for the control channel is set between the nodes where the link is established. For example, a VC path of a default VC3-1v set in advance is set.

  (Step S105) The traffic monitoring unit 208 monitors the amount of control channel traffic processed by the cross-connect unit 205 and measures the control channel bandwidth. For example, if the average value of the traffic amount of the control channel is 10 Mbps, the control channel bandwidth is set to 10M.

  (Step S106) The control channel management unit 209 determines whether or not the control channel bandwidth measured by the traffic monitoring unit 208 is greater than a predetermined ratio (X%) of the bandwidth of the entire transmission path. If the control channel band is greater than X% of the entire transmission path band, the process proceeds to step S107. If the control channel band is equal to or less than X% of the entire transmission path band, the process proceeds to step S108 and the process is terminated. For example, if the predetermined ratio X is set to 20% in advance, when the bandwidth of the entire transmission path is 155M, if the control channel bandwidth is greater than 31M, the process proceeds to step S107, and the control channel bandwidth is 31M or less. In this case, the process proceeds to step S108.

  (Step S107) A VC path for the control channel is added. For example, when the preset default VC path is VC3-4v, it increases to VC3-5v.

  (Step S108) The control channel construction process is terminated. In the flowchart of FIG. 5, for the sake of easy understanding, the one-time construction process is shown. Therefore, the control channel construction process is ended in step S108, but in reality, a new node is added or a new one is newly created. When the link is established, processing according to the flowchart of FIG. 5 is executed.

  As described above, the network transmission apparatus according to the present embodiment such as the node A, the node B, and the node C can be used as a control message transfer method without constructing another network for C-Plane for transmitting a GMPLS control message. Since the GMPLS control message is transmitted by forming a control channel in the transmission path between the network transmission apparatuses, it is possible to easily construct and manage the C-Plane. In addition, since the control channel bandwidth is varied so that the control channel bandwidth becomes a predetermined ratio of the transmission path bandwidth according to the traffic volume of the control channel, the control channel bandwidth is always kept within the predetermined ratio of the transmission path bandwidth. And the load on the transmission path band of the client signal can be reduced.

(Second Embodiment)
Next, a network transmission device and a control message transfer method according to the second embodiment will be described. The configuration of the GMPLS network using the network transmission device according to the second embodiment and the configuration of the network transmission devices (node A, node B, and node C) are the same as those shown in FIGS. 1 to 5 of the first embodiment. Since it is the same, the overlapping description is omitted.

  In the first embodiment, a description has been mainly given of processing when a link is newly established and a control channel is constructed. However, in the second embodiment, the control channel is preset after the control channel is constructed in the first embodiment. The process mainly monitors the control channel bandwidth at predetermined time intervals.

  FIG. 6 is a flowchart showing control channel monitoring processing. Note that the flowchart of FIG. 6 is processed around the control unit 206 of FIG. 4 as in the flowchart of FIG.

  (Step S201) Control channel (Control Channel) monitoring processing is started.

  (Step S202) It is determined whether or not a predetermined time (Y time) set in advance has elapsed since the previous monitoring process of the control channel band. If Y time has elapsed since the previous control channel bandwidth monitoring process, the process proceeds to step S203. If Y time has not elapsed since the previous control channel bandwidth monitoring process, the process proceeds to step S208 and the process is terminated. For example, when the control channel bandwidth is monitored every 10 minutes, the control channel bandwidth is varied only when 10 minutes have elapsed and 10 minutes have not elapsed. Does not control the bandwidth of the control channel.

  (Step S203) The traffic monitor unit 208 monitors the control channel traffic volume processed by the cross-connect unit 205 and measures the control channel bandwidth. This process is the same as the process of step S105 in the flowchart of FIG.

  (Step S204) The control channel management unit 209 determines whether or not the control channel bandwidth measured by the traffic monitoring unit 208 is greater than a predetermined ratio (X%) of the bandwidth of the entire transmission path. If the control channel bandwidth is greater than X% of the entire transmission path bandwidth, the process proceeds to step S206. If the control channel bandwidth is less than X% of the overall transmission path bandwidth, the process proceeds to step S205. This process is the same as the process of step S106 in the flowchart of FIG.

  (Step S205) The control channel management unit 209 determines whether or not the control channel bandwidth measured by the traffic monitoring unit 208 is smaller than a predetermined ratio (Z%) of the bandwidth of the entire transmission path. If the control channel band is smaller than Z% of the entire transmission path, the process proceeds to step S207. If the control channel band is equal to or greater than Z% of the entire transmission path, the process proceeds to step S208 and the process is terminated. For example, if the predetermined ratio Z is set to 30% in advance, when the bandwidth of the entire transmission path is 155M, if the control channel bandwidth is smaller than 46.5M, the process proceeds to step S207, where the control channel bandwidth is 46 If it is more than 5M, the process proceeds to step S208.

  (Step S206) A VC path for the control channel is added. For example, when the preset default VC path is VC3-4v, it increases to VC3-5v.

  (Step S207) The VC path for the control channel is reduced. For example, when the default VC path set in advance is VC3-4v, it is reduced to VC3-3v.

  (Step S208) The control channel monitoring process is terminated. In the flowchart of FIG. 6, for the sake of easy understanding, only one monitoring process is shown. Therefore, the control channel monitoring process is terminated in step S208. However, in practice, this monitoring process is always executed, and step S202 is executed. To determine whether or not a predetermined time (Y time) set in advance has elapsed.

  As described above, the network transmission apparatus according to the present embodiment such as the node A, the node B, and the node C can be used for the C-Plane for transmitting the GMPLS control message as a control message transfer method, as in the first embodiment. Since a GMPLS control message is transmitted by forming a control channel in a transmission path between network transmission apparatuses without constructing another network, it is possible to easily construct and manage a C-Plane.

  In addition, since the control channel bandwidth is varied so that the control channel bandwidth becomes a predetermined ratio of the transmission path bandwidth according to the traffic volume of the control channel, the control channel bandwidth is always kept within the predetermined ratio of the transmission path bandwidth. And the load on the transmission path band of the client signal can be reduced.

  Further, in the present embodiment, the bandwidth of the VC path for the control channel can be increased or decreased according to the increase or decrease of the control channel bandwidth, and in particular, the lower limit bandwidth (X%) and the upper limit bandwidth (Z%) can be set. ing. Due to this hysteresis effect, when the fluctuation of the control channel band is small, the VC path of the control channel is not changed, so that a stable control channel path band can be obtained and the processing load of the network transmission apparatus can be reduced. it can.

  As described above, as described in each embodiment, the network transmission device and the control message transfer method according to the present invention are for transmitting a control message of a GMPLS network without constructing another network for C-Plane. Since the control channel is formed in the transmission path formed between the network transmission apparatuses, the C-Plane can be easily constructed and managed.

It is a block diagram which shows the structural example of a GMPLS network. It is a block diagram which shows the structural example of the optical link between each node, and a transmission path. It is explanatory drawing which shows the structural example of VC, and the structural example of an SDH frame. 3 is a block diagram illustrating a configuration example of a node B. FIG. 6 is a flowchart showing a control channel construction process of a node B. 6 is a flowchart showing a control channel monitoring process of a node B. It is a block diagram which shows the structural example of the conventional GMPLS network.

Explanation of symbols

201, 202 ... SONET / SDH IF
203, 204 ... LO IF
205 ... Cross-connect unit 206 ... Control unit 207 ... GMPLS protocol processing unit 208 ... Traffic monitor unit 209 ... Control channel management unit 101a, 101b, 102a, 102b ... Optical link 103, 104 ... Optical link 151 ... Control channel transmission path 152 to 155 ... Transmission path for client signal

Claims (6)

In a control message transfer method for transferring a GMPLS control message via a link established between network transmission devices constituting a GMPLS network,
Forming a control channel for transmitting a GMPLS control message in a transmission path of a predetermined band formed in a link between the network transmission devices;
Monitor the amount of traffic on the control channel and vary the control channel bandwidth so that the bandwidth of the control channel falls within a predetermined ratio of the transmission path bandwidth
And a control message transfer method. The control message transfer method according to claim 1,
A control message transfer method, comprising: monitoring a traffic amount of the control channel at predetermined time intervals. In the control message transfer method according to claim 1 or 2,
If the control channel is not formed at the time when a link is established between network transmission devices constituting the GMPLS network, a new control channel is formed,
A control message transfer method characterized in that a new control channel is not formed when the control channel is already formed when a link is established between network transmission apparatuses constituting a GMPLS network. In a network transmission device constituting a GMPLS network,
Multiple SONET / SDH interfaces;
A link establishing unit for establishing a link between adjacent network transmission devices via the plurality of SONET / SDH interfaces;
A cross-connect unit for selectively connecting the plurality of SONET / SDH interfaces;
A GMPLS protocol processor for processing GMPLS control messages;
A control channel forming unit for forming a control channel for transmitting a GMPLS control message in a transmission path of a predetermined band formed in a link between the network transmission devices;
A traffic monitoring unit that monitors the traffic volume of the control channel processed by the cross-connect unit;
A control channel management unit that manages the control channel band so that the band of the control channel falls within a predetermined ratio of the transmission path band according to the amount of traffic monitored by the traffic monitor unit;
And a control unit that controls transmission path setting so that the control channel bandwidth is instructed by the control channel management unit. The network transmission device according to claim 4, wherein
The traffic monitor unit monitors the traffic amount of the control channel at predetermined time intervals. The network transmission device according to claim 4 or 5,
The control channel forming unit newly forms a control channel when the link is established between the network transmission apparatuses when the control channel is not formed, and newly forms when the control channel is already formed. A network transmission apparatus characterized by not forming a control channel.

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