JP2003338836A - Access network system and route controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To switch a route at high speed in inexpensive configuration on an IP network. <P>SOLUTION: Subscriber stations 11-14 and repeater stations A-E transfer subscriber data transmitted-received by subscriber terminals 1-4 via a VLAN by setting the VLAN by performing VLAN tagging to a transfer packet such that one VLAN becomes a line in a transfer plane P1 using a layer lower than a layer 3 in an OSI model. A network control block CU changes setting of the VLAN in accordance with traffic information collected from the subscriber stations and the repeater stations in a control plane P2 using the layer 3. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an access network system and a route control device, each of which is composed of a plurality of subscriber devices to which subscriber terminals are connected and a plurality of relay devices which relay between the subscriber devices, and more particularly, The present invention relates to an access network system and a route control device suitable for an access system that relays by broadband millimeter wave radio.

[0002]

2. Description of the Related Art Generally, in an IP network, an IP router controls the route of data transferred. The IP router determines the next-stage IP router to which the packet is to be relayed, based on the destination IP address of the IP packet. In an access network that connects a subscriber and an ISP (Internet Service Provider), the packet from the subscriber may show as the destination IP address, for example, the IP address of the host of the same portal site. However, since each subscriber has a contract with each ISP, the packet of the subscriber terminal has a contract I
It is necessary to pass through the SP network. Therefore, the packet from the subscriber terminal needs to be transmitted to the ISP to which the subscriber belongs regardless of the destination IP address.

For this reason, at present, as shown in FIGS. 10 and 11, the packet of the subscriber is sent to the private I within the access network.
It is transferred to the ISP network by tunneling the P network, and by encapsulating the packet of the subscriber terminal with the private IP indicating the IP of the router to which the ISP is connected, the IP router in the access network makes the ISP
(See, for example, Non-Patent Document 1 and Non-Patent Document 2 below).

[0004]

[Non-Patent Document 1] IP in IP Tunneling RFC1853 http://www.ietf.org/rfc/rfc1853.txt

[Non-patent document 2] IP Encapsulation within IP RFC2003 http://www.ietf.org/rfc/rfc2003.txt

[0005]

However, regarding the above method, in the method using IP encapsulation, it is necessary to encapsulate all user data to be transferred.
The processing load in the subscriber accommodation part is heavy, and high-speed software processing is required. In addition, in an access system that relays by broadband millimeter-wave wireless, "communication path disconnection" due to rainfall can be mentioned as a failure specific to millimeter-wave wireless. Therefore, in a wired network, applying a failure recovery method that switches failed links by duplicating physical links to millimeter-wave radio does not improve the wireless link status due to rainfall even if the wireless links are physically duplicated. ,
Not valid. Therefore, it is essential to change the route to bypass the fault route.

However, in the method using the IP encapsulation, the route of the user data follows the IP routing in the access network. Therefore, when switching the route when a failure occurs, it is necessary to wait until the new route is converged by the route control protocol. There is a problem that switching takes several tens of seconds.

In view of the above-mentioned problems of the conventional example, it is an object of the present invention to provide an access network system and a route control device which can switch routes at high speed with an inexpensive structure.

[0008]

In order to achieve the above-mentioned object, a plurality of subscriber devices to which subscriber terminals are connected and a plurality of relays for relaying between the subscriber devices are provided. And a network management unit that centrally manages traffic information of the entire network from the subscriber device and the relay device, and the subscriber device and the relay device each have one VLAN as a line. VLAN to transfer packet to VLAN
And transfer subscriber data transmitted and received by the subscriber terminal via the VLAN, and the network management means sets the VLAN according to the traffic information collected from the subscriber device and the relay device. It is characterized by changing the. With this configuration, it is possible to configure a network capable of controlling routes by using inexpensive and high-speed LAN devices as the subscriber device and the relay device.

According to a second aspect of the present invention, in the access network system according to the first aspect, the network management means is based on the traffic information of the entire network collected from the subscriber device and the relay device. It is determined whether or not the route needs to be switched, and when it is determined that the route should be switched, the subscriber device is instructed to change the setting of the VLAN according to the traffic information of the entire network. With this configuration, the route can be changed by the network management means based on the information of the entire network, and thus the traffic engineering of the entire network becomes possible.

According to a third aspect of the present invention, in the access network system according to the first aspect, whether or not each of the plurality of relay devices needs to switch a route based on each link state of its own device. And requesting the network management means to switch the route when it is determined that the network management means receives the route switching request, the subscriber device according to the traffic information of the entire network. Against the VL
I am instructed to change the setting of AN. With this configuration, the route change determination process can be distributed to each relay device, and the route change determination can be executed using a large amount of information in a finer cycle.

According to a fourth aspect of the present invention, in the access network system according to the third aspect, each of the plurality of relay devices needs to switch a route based on a reception packet error rate at each reception port of layer 2. I decided to judge whether there is. With this configuration, the route can be changed only when data is actually flowing through the link, and the frequency of the route change can be reduced.

The invention as defined in claim 5 is defined by claim 1 through claim 4.
In the access network system according to any one of items 1 to 3, the subscriber device and the relay device transfer subscriber data on a VLAN path by a transfer plane using a layer lower than layer 3 in the OSI model, The network management means transmits the control information for network management on the control plane using the layer 3. With this configuration, subscriber data can be transmitted at high speed.
While being transferred by the Ethernet (R) switch, the control information can be configured as another network by using different control and transfer methods.

According to a sixth aspect of the present invention, in the access network system according to the fifth aspect, the control data route flowing through the control plane is distributed and controlled by a layer 3 route control protocol. With this configuration, it is possible to autonomously and decentralize the route control relating to the control information for controlling the subscriber data route, so that a highly reliable network can be constructed.

According to a seventh aspect of the present invention, a plurality of subscriber devices to which subscriber terminals are connected, a plurality of relay devices that relay between the subscriber devices, and traffic information of the entire network are provided to the subscriber devices. And a route control device of the subscriber device and the relay device in an access network system comprising: a network management unit that collects and centrally manages the relay device, and transfers subscriber data transmitted and received by the subscriber terminal. As a route for doing so, a route setting means for setting two ports of each of the relay devices as a set so that the VLAN becomes a line on the network, and a route set by the route setting means are identified as one route. As an identifier for managing the mapping between the VID included in the VLAN tag and the subscriber terminal
It is characterized by having an ID management means and a VLAN tag adding means for adding a VLAN tag in a subscriber device to which the subscriber terminal is connected. With this configuration, VID
It is possible to control the route for each subscriber simply by setting

According to an eighth aspect of the invention, in the route control device according to the seventh aspect, the VID management means maps a plurality of VLAN routes to one subscriber terminal.
It is characterized in that the VLAN tag addition means changes the route by changing the VID when the network management means instructs the route change. With this configuration, it is possible to change the route at high speed.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION <First Embodiment> An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a network configuration according to the first exemplary embodiment of the present invention. The physical network of the present invention includes subscriber terminals 1 to 1.
4 and the relay stations A to E for relaying packets between the subscriber stations 11 to 14 are connected by millimeter wave radio. Subscriber stations 11-
Subscriber terminals 1 to 4 are connected to 14, and a relay station A is connected to an ISP.

Further, as shown in FIG. 1, the logical network of the present invention is mainly composed of two planes. One is a transfer plane P1 for transferring packets between the subscriber terminals 1 to 4 and for transmitting / receiving packets to / from an external network, and the other is closed in the access network to collect network information and join. It is the control plane P2 that executes the route setting of the user terminals 1 to 4.

FIG. 2A shows a protocol stack of the transfer plane P1, which is composed of a layer 2 (data link layer) network in the OSI model. Usually in a data link layer network,
Hosts that share a physical network share a broadcast domain, but IEEE80
Configure a VLAN (Virtual LAN) specified in 2.1Q, completely separate the broadcast domain, and then
Further, this network is set in each of the relay stations AE so as to form one route. As a result, it is possible to logically separate users only in layer 2 and physically transfer data. A route formed by such a VLAN (hereinafter, referred to as a VLAN route) has a form logically multiplexed by a VLAN tag.

On the other hand, FIG. 2B shows the protocol stack of the control plane P2, which is composed of layer 3 (network layer) in the OSI model and constitutes a closed IP network inside the access network. , Each relay station A to E, subscriber station 11 by normal IP routing
The transmission of the control information between 14 to 14 is executed. The control plane P2 collects the setting information and status of each of the relay stations A to E and the subscriber stations 11 to 14, and the transfer plane P1 is collected as necessary.
Change the route of.

FIG. 3 is a diagram showing a packet transfer device which is a configuration example of the relay device according to the present invention. The relay device (packet transfer device) is a wireless processing unit 2 that performs wireless transmission and reception.
1 and L2 that can switch Ethernet (R) packets corresponding to VLAN tags to transfer subscriber data
A processing unit 22 and an L3 processing unit 23 that performs IP route control for exchanging control information, transfers control data by IP address, and performs processing such as setting change.

More specifically, the L2 processing unit 22 includes an L2 packet transfer processing unit 22a that executes packet transmission / reception,
L2 for setting and managing the VLAN tag of the processing unit 22
It is composed of the transfer management unit 22b. Also, the L3 processing unit 23
Specifically, the L3 packet transfer processing unit 23a that executes transmission / reception of control packets and the route of control packets is notified,
The configuration includes a route control processing unit 23b for setting, and a device management unit 23c for exchanging device information with an external network management block CU (Control Unit: see FIGS. 4 and 5) and changing the setting of the subscriber data route. To be done. Also, the L2 processing unit 22 and the L3 processing unit 23 use one port Pn of the L2 packet transfer processing unit 22a to
A control network is connected by a LAN tag in a logically multiplexed form.

An example of a case where an access network is configured by using relay switches is shown in FIGS. 4 and 5. 4 and 5
Functions as a relay switch that relays packets between the subscriber wireless stations SW-1 to SW-6 and the subscriber wireless stations SW-1 to SW-6. Relay radio stations SW-A to SW-E 5
Subscribers PC1 to PC by configuring a network of units
6 are connected. Also, one of the relay radio stations SW-A
A network management block CU that manages the data path of the entire network is connected to.

FIG. 4 is a block diagram showing an example of setting the user data path of the subscriber terminal PC1. In the present invention, the route of the subscriber terminal PC is a VLAN tag and each relay radio station SW.
Specified by setting the ports from -A to SW-E.
Normally, a VLAN in Ethernet (R) is used for separating a broadcast domain and configuring a plurality of logical networks on the same physical network. However, in the present invention, one VLAN tag is supported for one switch. The feature is that the number of ports is limited to two and the network indicated by the VLAN tag is set as one route (line). In the example of FIG. 4, three different VLAN tags (VID = 1 to 3) are mapped to three different routes for the subscriber terminal PC1. In this way, the VID on the transfer plane P1 indicates one route of the subscriber terminal PC, and this route indicates one network.

Further, since the transfer plane P1 connects the subscriber terminals PC1 to PC6 and the ISP by the data link layer (L2), it is controlled in a form completely separated from the network layer protocol flowing thereabove. Therefore, it is possible to configure a route that does not depend on the protocol of the network layer (L3), and it is not necessary to change the route of the access network even when there is a change such as a change of the ISP by the subscriber. .

Taking the relay radio station SW-D as an example, VID = 1 is set in the ports P1 and P6 as shown in FIG.
ID = 2 is set to the ports P1 and P5, and VID = 3 is set to the ports P1 and P4. For the route of VID = 1, the same settings are made for the subscriber wireless station SW-1 and the relay wireless station S.
WB and SW-A are also performed, and as a route of VID = 1, SW-1 (P1, P2) -SW-D (P1, P
6) -SW-B (P1, P4) -SW-A (P4, P
2) is set.

The selection and switching of these three routes is controlled by the subscriber radio station SW-1 which is a subscriber station so that the subscriber terminal PC1 does not become aware of the VLAN tag. Therefore, the subscriber wireless station SW-1 is connected to the port to which the subscriber terminal PC1 is connected and the relay wireless station S1.
The mapping setting with the VLAN tag used in the connection port to WD is held, and the corresponding VLAN tag is added or deleted. The VID setting and the mapping setting for each device are centrally managed by the network management block CU that operates as a data path management unit.
It is set in each wireless station SW as control information by P (Simple Network Management Protocol). As described above, in the present invention, the data paths of the subscriber terminals PC1 to PC6 are centrally managed by the network management block CU, and control / setting is executed. By doing so, the subscriber data can be operated only by the transfer processing by the L2 processing unit 22 after the setting from the network management block CU is completed.

FIG. 5 is a block diagram showing network settings for transfer of control packets. The L3 processing unit 23 executes the transfer process for the control packet. Therefore, it is necessary to set such that the switches SW are identified as different networks having different network addresses. In the figure, each link between each switch has one network address, and the switch SW operates as a router.

Taking the relay radio station SW-D as an example, the networks NW-3, NW-4, NW-5, NW-6, NW-7, whose ports of the relay radio station SW-D are different from each other, are shown.
It operates as NW-13. Therefore, the VID of the VLAN
In contrast to the mapping to the subscriber terminal PC in order to show the subscriber data path in the transfer plane P1, it will be mapped to each network NW, that is, a link.

A setting example of the relay radio station SW-D will be described with reference to FIGS. 7 and 8. FIG. 7 shows L of the relay radio station SW-D.
2 shows an example of setting in the processing unit 22. In the L2 processing unit 22, the VID and the port address to be used are set similarly to the setting of the data path of the subscriber. Here, the difference from the setting of the subscriber's data path is that one of the connected ports must be L
3 is a portion that becomes Pn which is a connection port to the processing unit 23. With this setting, each port of the relay wireless station SW is logically multiplexed in the form of VLAN and is recognized by the L3 processing unit 23.

FIG. 8 shows the L3 processing unit 2 of the relay radio station SW-D.
An example of setting to 3 is shown. The L3 processing unit 23 is a relay wireless station SW
Since each port is identified as a network, the VID indicating each port and the IP address of the network NW assigned to that port are mapped and set. As described above, since the settings related to the user data and the control data are the same for the L2 processing unit 22, the L2 processing unit 22 executes the transfer processing without being aware of the type of data, and as a result, the user data and the control are controlled. Data can be separated.

All the separated control data are transferred to the L3 processing section 23. In the L3 processing unit 23, I
The P address is used to execute the same processing as a normal IP router. When the destination IP address is not the own IP address, the next transfer destination is searched according to the routing control table held internally, and the packet transfer is executed. In the route control processing unit 23b, the RIP (Routing Information Protoco
Using a general routing control protocol such as l) or OSPF (Open Shortest Path First), the routing information of the network for transferring the control data is exchanged to configure the routing control table. When the destination IP address is the own IP address, the packet is received and the process is executed. If the received packet is a packet of the L3 route control protocol, the route control processing unit 23b executes the process. If the received packet is SNMP, the device management unit 23c executes the process.

Next, the route changing procedure will be described with reference to FIG. FIG. 9 shows a procedure of exchanging control information activated by a timer and changing a route according to the contents. In this embodiment, the CU is each switch SW
Information is collected using SNMP to determine the necessity of changing the user data path (step S1). For example, when an unusable route occurs due to a radio link failure, it is necessary to change the route for a user who uses a VID passing through this route. In the first embodiment, switching due to a link failure is shown, but in the present invention, there is no particular need to be a failure regarding the material for determining the route change,
The determination may be made based on the amount of traffic and is not limited to this.

When it is necessary to change the data path of a certain user, the CU searches for a subscriber who uses the corresponding path (step S2), and then uses it for the subscriber edge switch to which the corresponding user terminal PC is connected. The control information describing the value of VID to be set is set using SNMP (step S3). In the subscriber station that has received this control information, the device management unit 23c of the L3 processing unit 23 performs processing, and
The L2 transfer management unit 22b of the processing unit 22 is caused to execute the setting of mapping of the subscriber terminal and VID (step S).
4). When the mapping of the subscriber terminal and the VID in the L2 transfer management unit 22b is completed, a new VID is added to the packet of the subscriber terminal, and the packet is transmitted through the VLAN route indicated by this VID. You will be told. In the present invention, the route of the user can be switched only by changing the mapping setting of the subscriber terminal and VID to the subscriber station, and high-speed route switching is realized.

<Second Embodiment> The second embodiment differs from the first embodiment in that the route change determination means is provided not in the network management block CU but in each of the relay stations AE. FIG. 12 shows a route changing procedure in the second embodiment. In FIG. 12, a plurality of relay stations A to
Although there are E and subscriber stations 11 to 14, only one is shown for ease of viewing the figure. In each of the relay stations A to E, the device management unit 23c of the L3 processing unit 23 illustrated in FIG. 3 periodically executes the route change determination process (step S11). As a result, when it is determined that there is a failure in the link of the own device,
The TRAP of SNMP is used as the route change request to notify the link to be changed (step S12).

The network management block CU that has received this route change request executes a search for the subscribers who use the link to be changed (step S13), and a plurality of subscriber terminals (1 to 4) are mapped. A route that does not pass through the corresponding link is selected from the existing VIDs (step S14). After that, the route information in which the value of the VID indicating the new route is recorded is sent to each of the subscriber stations 11 to 14 by SNMP.
Is used to set (step S15). Regarding the subsequent processing (step S16), the first embodiment shown in FIG.
This is similar to (step S4).

Next, the relay stations A to E in the second embodiment
The route change determination processing in step 3 will be described in detail with reference to the flowchart of FIG. In the second embodiment, the L2 transfer management unit 22b of the L2 processing unit 22 shown in FIG.
The feature is that the information of is used. L2 transfer management unit 22
b, the standard MIB (Mana
gement Information Base) is implemented, and statistical information such as the number of input / output packets, the number of bytes, and the number of error packets is stored for each port. In the route change determination process, statistical information is periodically acquired from the L2 transfer management unit 22b (step S21), and the error rate of the received packet is calculated from the number of input packets and the number of input error packets. When the error rate of the received packet becomes larger than the threshold value X (step S22), it is determined that there is a link failure and a route change request is transmitted to the network management block CU (step S2).
3).

As described above, in the second embodiment, since the link failure is judged based on the rate of error packets actually received from the corresponding link, the error is generated regardless of the actual bit error rate in the radio link layer due to rainfall or the like. If the packet is not dropped due to, the route change will not occur. Even if the bit error rate of the radio link layer increases due to rainfall, this is a wasteful route change when there is no data flowing, the throughput is low, and the packet drop is not so affected. Will prevent that.

[0038]

As described above, according to the present invention,
Existing VLAN-compatible Ethernet (R) switch and SNMP
, The broadcast domain of the VLAN is set to form one line, and the route can be selected only by the setting in the subscriber device. Therefore, the route control for each subscriber and the route of one subscriber can be performed. The system can be constructed at low cost while enabling change control. Further, since the route change judging means is provided in each relay device to judge the route change based on the error rate of the received packet in the route change judging process, there is an effect of reducing the unnecessary route change.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a network configuration according to a first exemplary embodiment of the present invention.

2A is an explanatory view showing a protocol stack of a transfer plane in the network of FIG. 1, and FIG. 2B is an explanatory view showing a protocol stack of a control plane in the network of FIG.

3 is a block diagram showing a packet transfer device which is a configuration example of a relay device which constitutes the relay station and a subscriber station in FIG.

FIG. 4 is a block diagram showing subscriber data paths on the network of FIG.

5 is a block diagram showing a route control of control information on the network of FIG.

6 is an explanatory diagram showing a setting example of a user data path of a relay wireless station SW-D in FIG.

7 is an explanatory diagram showing a setting example of an L2 processing unit of the relay wireless station SW-D in FIG.

8 is an explanatory diagram showing a setting example of an L3 processing unit of the relay wireless station SW-D in FIG.

FIG. 9 is a sequence diagram showing a route control method according to the first embodiment of the present invention.

FIG. 10 is a block diagram showing a network configuration based on a conventional IP.

11 is an explanatory diagram showing a protocol stack of a transfer plane and a control plane in the network of FIG.

FIG. 12 is a sequence diagram showing a route control method according to the second embodiment of the present invention.

FIG. 13 is a flowchart showing route change determination processing according to the second embodiment of the present invention.

[Explanation of symbols]

1-4, PC1-PC6 subscriber terminals 11-14 Subscriber stations 21 Wireless processing unit 22 L2 processing unit 22a L2 packet transfer processing unit 22b L2 transfer management unit 23 L3 processing unit 23a L3 packet transfer processing unit 23b Route control processing unit 23c Device management unit AE relay station CU network management block NW-1 to NW-15 networks SW-1 to SW-6 Subscriber radio stations SW-A to SW-E Relay radio station

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshihiro Suzuki             3-1, Tsunashima-Higashi 4-chome, Kohoku-ku, Yokohama-shi, Kanagawa             No. Panasonic Mobile Communicator             Within Chonz Co., Ltd. (72) Inventor Hiroyo Ogawa             4-2-1 Kanaikitamachi, Koganei City, Tokyo Independent             Communications Research Laboratory (72) Inventor Eiji Okamoto             4-2-1 Kanaikitamachi, Koganei City, Tokyo Independent             Communications Research Laboratory F-term (reference) 5K030 GA03 HD03 KA05 LB08 MB05                       MC08 MD07

Claims (8)

[Claims] 1. A plurality of subscriber devices to which subscriber terminals are connected, a plurality of relay devices for relaying between the subscriber devices, and traffic information of the entire network is collected from the subscriber devices and the relay device. And a network management unit for centrally managing the subscriber device and the relay device.
The VLAN is set by VLAN tagging the transfer packet so that the LAN becomes a line, and the subscriber data transmitted / received by the subscriber terminal is transferred via the VLAN. An access network system configured to change the setting of the VLAN according to the traffic information collected from a relay device. 2. The network management means determines whether or not it is necessary to switch a route based on the traffic information of the entire network collected from the subscriber device and the relay device, and when it is determined to be necessary. The access network system according to claim 1, wherein the subscriber device is instructed to change the setting of the VLAN according to the traffic information of the entire network. 3. Each of the plurality of relay devices determines whether or not it is necessary to switch the route based on each link state of its own device, and when it determines that the route needs to be switched, it switches the route to the network management means. The request is made, and the network management means, when receiving the path switching request, instructs the subscriber device to change the setting of the VLAN according to the traffic information of the entire network. Access network system described. 4. Each of the plurality of relay devices is a layer 2
4. The access network system according to claim 3, wherein it is determined whether or not the route needs to be switched based on the reception packet error rate at each reception port. 5. The subscriber device and the relay device transfer subscriber data on a VLAN path by a transfer plane using a layer lower than layer 3 in the OSI model, and the network management means is for network management. The access network system according to any one of claims 1 to 4, wherein the access network system is configured to transmit the control information of (1) on a control plane using the layer 3. 6. The access network system according to claim 5, wherein the control data path flowing through the control plane is distributed and controlled by a layer 3 path control protocol. 7. A plurality of subscriber devices to which subscriber terminals are connected, and a plurality of relay devices for relaying between the subscriber devices.
A routing control device for the subscriber device and the relay device in an access network system, comprising: network management means for collecting traffic information of the entire network from the subscriber device and the relay device and centrally managing the traffic information. As a route for transferring the subscriber data transmitted and received by the personal terminal, a route setting unit that sets two ports of each of the relay devices so that the VLAN becomes a line on the network, and the route setting unit sets VID that manages the mapping between the VID included in the VLAN tag and the subscriber terminal as an identifier for identifying the route that is set as one route
A route control device comprising: management means; and VLAN tag addition means for adding a VLAN tag in a subscriber device to which a subscriber terminal is connected. 8. The VID management means maps a plurality of VLAN paths to one subscriber terminal in advance, and the VLAN tag addition means changes the VID when the network management means instructs a path change. The route control device according to claim 7, wherein the route control device is configured to change the route.