JP6592421B2 - Routing system and routing method - Google Patents

Description

  The present invention relates to a routing system and a routing method.

  An IP (Internet Protocol) network such as the Internet is formed by connecting a number of ASs (Autonomous Systems) operated by different organizations. AS refers to a set of IP networks and routers under one or more routing policies connected to the Internet. The AS is a range of a network that manages routes by, for example, one route selection protocol. A router is arranged in the AS, and when data is transmitted, which route is used to transmit the data is determined by the routing protocol. Routing protocols can be broadly divided into IGP (Interior Gateway Protocol) for AS and BGP (Border Gateway Protocol) for AS. The IGP is used when data is transmitted to a destination in the AS, and the BGP is used when data is transmitted between different ASs. Then, IGP and BGP establish an adjacent relationship (peer) between routers that transmit data, exchange mutual route information, and determine a route for transmitting data to a predetermined destination based on the exchanged route information. To do. In BGP, BGP used between different ASs is called eBGP (external BGP), and BGP used in AS is called iBGP (internal BGP) to distinguish them. Note that iBGP is used when transferring BGP information from another AS to another AS.

  The route information exchanged by IGP or BGP is formed including a prefix and path attribute information. The prefix is a set of destination addresses represented by a network address and a netmask of the network address. The path attribute information is attribute information of the route added to the route information, and is a parameter used when selecting a route.

Non-Patent Document 1 describes the definition of a routing table in an IP network.
The Internet connection provider network and the concentrator network are connected by a POI (Point Of Interface), and the POI server sends packets addressed to the Internet to source information (which connection provider the user belongs to) To the appropriate carrier network according to the information). As an implementation method according to the current operation control method, there is PBR (Policy-Based Routing) that determines a transfer destination based on both a transmission source and a destination.

  Non-Patent Documents 2 to 4 describe PBR in a commercial transfer device. The PBR routes a packet based on a route map in which a network administrator defines a policy (specific rule). All packets received on an interface with PBR enabled pass through an extended packet filter called a route map. The route map used in PBR requests a policy and determines a packet transfer destination. A route map consists of statements. If the statement is marked as rejected, packets that match the match criteria are usually sent back through the forwarding channel to perform destination-based routing.

FIG. 13 is a diagram illustrating the network model A.
As shown in FIG. 13, the concentrator network 1 includes POIs 11 _{1 to} 11 ₃ , relay routers 12 _{1 to} 12 ₆ , and edge routers 13 _{1 to} 13 ₃ that are gateway routers (GWR). The POIs 11 _{1 to} 11 ₃ connect to the Internet 2 via the connection provider networks 3 _{1 to} 3 ₃ . The edge routers 13 _{1 to} 13 ₃ connect the relay routers 12 _{1 to} 12 ₃ to the end users 4 ₁ to 4 ₆ . The concentrator network 1 is an IP network. The topology within the concentrator network 1 may be anything. When the POIs 11 _{1 to} 11 ₃ are collectively referred to, they are referred to as POI 11. Similarly, if a generic term for relay routers ₁₂ 1 to 12 _6, referred to as the relay router 12, it may be collectively edge router _{131-134 3} is referred to as the edge router 13. The end users 4 ₁ to 4 ₆ are user terminals including, for example, a general personal computer or a portable information terminal.
For Figure 13, POI11 ₁ is connected provider network _{3 1} and concentrator provider network within 1 (hereinafter, referred to as the network) connects the relay routers 12 _1, POI11 ₂ includes a connection provider network _{3 2} connecting the relay routers 12 ₂ in the network, POI11 ₃ connects the relay routers 12 ₃ of the connection carrier network _{3 3} and reticuloendothelial. Relay router 12 ₆ edge router 13 ₁ is connected to, and are further end-user ₄ 1 via the edge router 13 _{1, 4 2} connected. Edge router ₁₃ 2, 13 ₃ is connected to the relay router 12 _5, and further the end user ₄ 3 via the edge router 13 _{2, 4 4} connecting the end user ₄ 5 via the edge router 13 _{3, 4 6} Is connected.

The address block information assigned to the end user in the network and the advertisement / distribution method of the network default route are assumed as follows. The advertisement of the address block information is indicated by the symbol a in FIG. Distribution of the default route in the network from the gateway router (POI 11) is indicated by reference numeral b in FIG.
As shown by the symbol a in FIG. 13, the address block information assigned to the end user (end user 4 ₂ ) in the network is advertised and exchanged via the BGP protocol.
On the other hand, as shown by reference numeral b in FIG. 13, from the gateway router (POI11 ₁₎ is distributed reticuloendothelial default route in BGP protocol, further if the destination is on each of the relay routers ₁₂ 1, 12 ₆ is not within the address nets A routing table is set so as to forward the packet to the GWR.

FIG. 14 is a diagram illustrating the network model B. The same components as those in FIG. 13 are denoted by the same reference numerals.
As shown in FIG. 14, the concentrator network 1 includes gateway routers (GWR) POIs 11 _{1 to} 11 ₃ , relay routers 12 _{1 to} 12 ₆ , and edge routers 13 _{1 to} 13 ₃ . The POIs 11 _{1 to} 11 ₃ connect to the Internet 2 via the connection provider networks 3 _{1 to} 3 ₃ . The edge routers 13 _{1 to} 13 ₃ connect the relay routers 12 _{1 to} 12 ₆ to the end users 4 ₁ to 4 ₆ .
The network model B includes an independent route server 10 different from the line concentrator network 1. The route server 10 includes a server or a router. The route server 10 has a route information management function and centrally manages information. The route server 10 provides resources for realizing a route information management function, and is a so-called computing resource equipped with a CPU, a memory, a storage, a network processor, and the like. The route server 10 may be installed outside the concentrator network 1.

The address block information assigned to the end user in the network and the advertisement / distribution method of the network default route are assumed as follows. The advertisement of the address block information is indicated by reference sign c in FIG. Distribution of the default route in the network from the gateway router (POI 11) is indicated by reference numeral d in FIG.
As indicated by reference numerals c and d in FIG. 14, the information is distributed from the route server 10 to each router (relay router 12 ₁ , edge router 13 ₁ ) in the network, and a routing table is set.

Requirements for IP Version 4 Routers, p74 [online], [October 31, 2016 search], Internet <URL: http://www.rfc-editor.org/rfc/rfc1812.txt> Aprisia "AprisiaNP Series User's Guide", p1 Cisco "Configuring Policy-Based Routing", p2 Juniper Nwtworks "Firewall Filters Feature Guide for EX9200 Switches", p331

When the position of the POI with the connection provider network is changed due to the change of the service model, the traffic distribution control function for the connection provider may be transferred from the gateway router to the relay router depending on the network configuration. With the transition of the traffic distribution control function from the gateway router to the relay router, the relay router needs to perform route control based on both the source information and the destination information.
If the route control on the relay router is to be performed by PBR, the destination information under this application condition is “full route” indicating all the route information on the Internet, or the end in the network. Any of the “intra-network prefixes” indicating address block information to be assigned to the user, and the general assumed number is enormous (for example, the number of entries by the full route is 1 million, the number of entries by the intra-network prefix is 1) Million). Therefore, when creating a policy table, which is a PBR routing table, the number of table entries increases explosively with an enormous number of destination designations. For this reason, since it becomes a scale greatly exceeding the performance range of a commercial device, there is a problem that it is difficult to perform network control in accordance with the POI change with the current method.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a routing system and a routing method for realizing desired path control by dramatically reducing the number of entries in the policy table. .

  In order to solve the above-mentioned problem, the invention according to claim 1 is a full route showing all route information on the Internet in the concentrator network connecting the end user and the Internet connection operator network. A routing system that performs route control by policy-based routing using any one of in-network prefixes indicating address block information to be assigned to the end user in a carrier network, the concentration company network and the Internet connection carrier network A POI (Point Of Interface), which is a gateway for connecting the network, a relay router connected to the POI or another router, and the end user and the relay router or another router in the network An edge router, and the relay router is addressed to the intra-network prefix. An extended routing table that sets all the route controls, sets the destination address, its forwarding destination, and the table to be referred to, and a policy table that sets the conditions of the packet to be controlled and its forwarding destination A storage unit for storing, and when a packet flows in, first, the extended routing table is searched, and when a table to be referred is specified, a control unit that performs reference order control of the table for searching the policy table is provided. The routing system is characterized by that.

  Further, the invention according to claim 7 is that in the concentrator network connecting the end user and the Internet connection operator network, a full route indicating all route information on the Internet, or the network in the concentrator network. A routing method of a routing system that performs route control by policy-based routing using any one of in-network prefixes indicating address block information assigned to an end user, and connects the concentrator network and the Internet connection network A point of interface (POI), a relay router connected to the POI or other router in the network of concentrators, and an edge router that connects the end user to the relay router or other router And the relay router has a route addressed to the intra-network prefix. Stores the extended routing table that sets all the controls, sets the destination address, its forwarding destination, and the table to be referred to, and the policy table that sets the conditions of the packet to be controlled and its forwarding destination When the packet flows in, the extended routing table is first searched, and when the table to be referred is specified, the reference order control of the table for searching the policy table is performed. And the routing method.

  In this way, the extended routing table is searched first, and the policy table is searched for the first time when a table to be referenced is specified. Therefore, the number of entries in the policy table can be significantly reduced. It can be handled with medium specs. Desired route control can be realized by avoiding destination designation in policy-based routing which is a bottleneck. For example, network control accompanying POI change can be performed.

  Further, the invention according to claim 2 is characterized in that, when the destination of the incoming packet is on the extended routing table, the control unit performs route control for the intra-network prefix. It was.

  In this way, since the extended routing table sets all the route control addressed to the intra-network prefix, the route control addressed to the intra-network prefix can be performed in the same manner as general policy-based routing.

  According to a third aspect of the present invention, there is provided a routing system wherein the control unit performs route control for the intra-network prefix when there is a corresponding destination on the extended routing table.

  By doing so, policy-based routing similar to conventional route control using a routing table can be executed, and for example, network control associated with POI change can be performed.

  According to a fourth aspect of the present invention, there is provided a routing system characterized in that route control in the concentrator network is route control in an AS (Autonomous System).

  By doing in this way, the route in AS which autonomously determines a route | route which each router arrange | positioned in AS (range of the network which manages the route by the route selection protocol) transmits a packet. Can be applied to control.

  The address block information assigned to the end user in the concentrator network may be advertised / exchanged via the BGP protocol, and the POI may use the BGP default route in the network from the POI. The routing system is further characterized in that the extended routing table is set in the router including the relay router so that the packet is forwarded to the POI when the destination is not an in-network address.

  In this way, the present invention can be applied to a network model that performs address block information assigned to an end user in the network and a method for advertising / distributing a default route in the network.

  Further, the invention according to claim 6 has a route information management function that is different from the concentration provider network in the address block information and the default route information in the network allocated to the end user in the concentration provider network. An independent server or router centrally manages, routing information is distributed from the server or router to the router including the relay router in the line operator network, and an extended routing table of the relay router is set. The characteristic routing system was adopted.

  In this way, the present invention can be applied to a network model that is centrally managed by an independent server or router having a route information management function.

  ADVANTAGE OF THE INVENTION According to this invention, the routing system and routing method which implement | achieve desired path control by reducing the number of entries of a policy table markedly can be provided.

It is a block diagram which shows the routing system which concerns on embodiment of this invention. It is a block diagram which shows the routing system which concerns on embodiment of this invention. It is a block which shows the structure of the routing system which concerns on embodiment of this invention. It is a figure which shows the structural example of the routing table of the routing system which concerns on embodiment of this invention. It is a figure which shows the structural example of the extended routing table of the routing system which concerns on embodiment of this invention. It is a figure which shows the structural example of the policy table of the routing system which concerns on embodiment of this invention. It is a control sequence diagram of the routing system according to the embodiment of the present invention. It is a figure explaining each route table setting of the routing system which concerns on embodiment of this invention, and the mode of a route search. It is a setting example of the extended routing table in the case of each route table setting and route search of the routing system which concerns on embodiment of this invention. It is a figure explaining the network control before change accompanying the position change of POI which exists in multiple numbers between the internet connection provider network of the routing system which concerns on embodiment of this invention, and a concentrator network. It is a figure explaining the network control after change accompanying the position change of POI which exists in multiple numbers between the Internet connection provider network of the routing system which concerns on embodiment of this invention, and a concentrator network. It is a figure explaining the network control after change accompanying the position change of POI which exists in multiple numbers between the Internet connection provider network of the routing system which concerns on embodiment of this invention, and a concentrator network. It is a figure which shows the conventional network model A. It is a figure which shows the conventional network model B. FIG. It is a figure which shows the verification of each routing table scale of the relay router before and after POI change with respect to the specifications of a commercial device as a table.

Hereinafter, a routing system and the like in a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described with reference to the drawings.
(Background explanation)
When the POI with the connected carrier network is changed (including addition of POI) due to a change in the service model, etc., when the traffic distribution control function for the connected carrier is shifted from the gateway router to the relay router due to the network configuration There is.
FIG. 10 and FIG. 11 are diagrams for explaining network control in accordance with the position change (including addition of POI) of a plurality of POIs existing between the Internet connection provider network and the concentrator network. Before the change, FIG. 11 shows the change. The same components as those in FIG. 13 are denoted by the same reference numerals.
<Before change>
As indicated by a symbol e in FIG. 10, the POI 11 transfers a packet addressed to the Internet to an appropriate connection operator network (connection operator network 3A or connection operator network 3B) according to user information.

<After change>
As shown in FIG. 11, when a POI position change (for example, addition of POI 11A) is performed due to a service model change or the like, in the relay router (here, relay router 12A) close to POI 11A, the source information And route control based on both the destination information and the destination information. The transmission source information is information indicating which connection provider the user belongs to. In addition, as a method of implementation according to the current operation control method, there is “policy-based routing” in which a transfer destination is determined based on both a transmission source and a destination.
That is, with the transition of the traffic distribution control function from the POI 11A shown in FIG. 11 to the relay router 12A, the relay router 12A needs to perform route control based on both the source information and the destination information. For example, as indicated by a symbol f in FIG. 11, the relay router 12A performs transfer to the connection operator A destined for the Internet by route control based on both the source information and the destination information. Further, as indicated by a symbol g in FIG. 11, the relay router 12A performs transfer to the connection operator B destined for the Internet. Further, as indicated by the symbol h in FIG. 11, the relay router 12A performs transfer to the connection carrier A or B addressed to the in-network address.

When the route control on the relay router (relay router 12A) is to be performed by the route control by policy-based routing, the destination information corresponds to “full” indicating all the route information on the Internet under this application condition. Route ”or“ intra-network prefix ”indicating address block information to be assigned to the end user 4 in the network, and the general assumed number is enormous (for example, the number of entries by the full route: 1 million) , The number of entries in the network prefix: 10,000).
Therefore, when creating a policy table, which is a route table for policy-based routing, the number of table entries increases explosively with the designation of a large number of destinations, and the scale greatly exceeds the performance range of commercial devices. For this reason, it is difficult to perform network control accompanying the POI position change with the current method.

  FIG. 12 is a diagram for explaining the network configuration after the POI change. The same components as those in FIG. 11 are denoted by the same reference numerals. FIG. 15 is a table showing verification of each route table size of the relay router A before and after the POI change with respect to the specifications of the commercial device. FIG. 15 shows the number of entries in the routing table (as viewed in FIB (Forwarding Infrmatin Base)) and the policy table (as viewed in ACL (Access Control List)) after the POI change in this embodiment and the comparative example. In contrast. In the table of FIG. 15, a circle mark (◯ mark) indicates that it can be handled by the commercial device specification, and a cross mark indicates that it is difficult to handle by the commercial device specification. The column after (1) POI change in the comparative example of FIG. 15 corresponds to the path control of (1) in FIG. 12, and the column after (2) POI change in the comparative example of FIG. ) Path control.

<Comparative Example 1>
As shown in (1) of FIG. 12, the relay router 12A changes the POI 11A with the connection operator A addressed to the in-network address. Specifically, the relay router 12A performs routing by specifying the end user / destination belonging to the transmission source: connection carrier A: full route. In this case, the number of entries in the policy table reaches 62 million entries, for example, and cannot be realized with the commercial device specifications. To avoid this, it is conceivable to devise the description of the policy table.

<Comparative Example 2>
As shown in (2) of FIG. 12, the relay router 12A performs routing by specifying an end user / destination belonging to the transmission source: connection carrier B / destination: prefix in the network (prefix). Source not corresponding to the above: An end user (that is, destined for the full route) belonging to the connection carrier A routes to the GWR. In other words, not everything is specified by full route designation, but priority is given to in-network prefix designation depending on the transmission source.
By devising the policy table description method, the number of entries is reduced to, for example, 720,000 entries. Although the number of entries is reduced to about 1/8 compared with the case where all the routes are designated, it can be seen that the number of entries is still in a scale that cannot be handled in the category of commercial devices.

(Embodiment)
FIG. 1 is a configuration diagram showing a routing system according to an embodiment of the present invention. It is an example applied to the relay router of the network operator network of network model A in FIG. The same components as those in FIG. 13 are denoted by the same reference numerals.
The routing system 100 </ b> A is a full route indicating all route information on the Internet in the concentrator network 1 connecting the end user 4 and the Internet connection operator network 3, or the end user 4 in the concentrator network 1. Route control by policy-based routing using any one of the intra-network prefixes indicating the address block information assigned to the network is performed.

As shown in FIG. 1, a concentrator network 1 includes POIs 11 _{1 to} 11 ₃ , POIs 110, which are gateway routers (GWR), relay routers 120, relay routers 12 _{1 to} 12 ₅ (other routers), and edge routers 13. _{1-13 3} exists.
The POIs 11 _{1 to} 11 ₃ connect to the Internet 2 via the connection provider networks 3 _{1 to} 3 ₃ .
The POI 110 is a gateway router (GWR) whose position has been changed (added).
The relay router 120 is an in-network router connected to any of the POI 110 and the relay routers 12 _{1 to} 12 ₅ (described later). In the case of FIG. 1, the relay router 120 is connected to the POI 110 and the relay routers 12 ₁ and 12 ₅ .
The edge routers 13 _{1 to} 13 ₃ connect the relay routers 12 _{1 to} 12 ₅ and 120 to the end users 4 ₁ to 4 ₆ .

The route control in the concentrator network 1 is route control in AS (Autonomous System). The concentrator network 1 is an IP (Internet Protocol) network. The topology within the concentrator network 1 may be anything.
When the POIs 11 _{1 to} 11 ₃ are collectively referred to, they are referred to as POI 11. Similarly, if a generic term for relay routers ₁₂ 1 to 12 _5, referred to as the relay router 12, it may be collectively edge router _{131-134 3} is referred to as the edge router 13. The end users 4 ₁ to 4 ₆ are collectively referred to as end users 4. The end users 4 ₁ to 4 ₆ are user terminals including, for example, a general personal computer or a portable information terminal.

For Figure 1, POI11 ₁ is connected provider network _{3 1} and concentrator provider network within 1 (hereinafter, referred to as the network) connects the relay routers 12 _1, POI11 ₂ includes a connection provider network _{3 2} connecting the relay routers 12 ₃ in the network, POI11 ₃ connects the relay routers 12 _fourth connection carrier network _{3 3} and reticuloendothelial. Edge router ₁₃ 2, 13 ₃ is connected to the relay router 12 _5, and further the end user ₄ 3 via the edge router 13 _{2, 4 4} connecting the end user ₄ 5 via the edge router 13 _{3, 4 6} Is connected. End users 4 ₁ and 4 ₂ are connected to the relay router 120 via the edge router 13 ₁ .

The address block information assigned to the end user 4 in the network and the advertisement / distribution method of the network default route are assumed as follows. That is, the address block information assigned to the end user 4 in the network is advertised and exchanged via the BGP protocol. On the other hand, POIs 11 _{1 to} 11 ₃ and POI 110 distribute the default route in the network using the BGP protocol, and further forward the packet to GWR if the destination is not an in-network address to relay routers 12 _{1 to} 12 ₅ and 120. Set up a routing table.

  The present embodiment is characterized in that the relay router 120 has the extended routing table 210 (see FIG. 3) and the reference order of the route tables (the extended routing table 210 and the policy table 220). Therefore, any network model including the relay router 120 may be used, and the configuration of the network model is not limited. For example, the relay router 120 may be applied to the network model B in FIG.

FIG. 2 is a configuration diagram showing the routing system according to the embodiment of the present invention. It is the example applied to the relay router of the concentrator network of the network model B of FIG. The same components as those in FIG. 14 are denoted by the same reference numerals.
As shown in FIG. 2, the concentrator network 1 includes POIs 11 _{1 to} 11 ₃ , POI 110, relay routers 12 _{1 to} 12 ₅ and 120, and edge routers 13 _{1 to} 13 _{3 which} are gateway routers (GWR). . The POIs 11 _{1 to} 11 ₃ connect to the Internet 2 via the connection provider networks 3 _{1 to} 3 ₃ . The edge routers 13 _{1 to} 13 ₃ connect the relay routers 12 _{1 to} 12 ₅ and 120 to the end users 4 ₁ to 4 ₆ .

The network model B shown in FIG. 2 includes an independent route server 10 that is different from the concentrator network 1. The route server 10 is an independent server or router having a route information management function, which is different from the line concentrator network 1. The route server 10 has a route information management function and centrally manages information. The route server 10 provides resources for realizing the route information management function.
The address block information assigned to the end user 4 in the network and the advertisement / distribution method of the network default route are assumed as follows. That is, the information is distributed from the route server 10 to each of the relay routers 12 _{1 to} 12 ₅ and 120 in the network, and the routing table 200 and the extended routing table 210 are set.

[Routing system]
FIG. 3 is a block diagram showing the configuration of the routing system according to the embodiment of the present invention.
The routing systems 100A and 100B include POIs 11 and 110, which are gateways that connect the concentrator network 1 and the Internet connection operator network 3, and relay routers 120 that are connected to the POI 110 or other routers in the concentrator network 1. And an edge router 13 that connects the end user 4 and the relay router 120 or another router.
The POIs 11 and 110 include a routing table 200 (see FIG. 4) and a policy table 220 (see FIG. 6).
The edge router 13 includes a routing table 200 (see FIG. 4) and a policy table 220 (see FIG. 6).

The relay router 120 includes a control unit 121, a reception unit 122, a transfer unit 123, an extended routing table 210 (storage unit) (see FIG. 5), and a policy table 220 (storage unit) (see FIG. 6). Prepare. The relay router 120 includes an extended routing table 210 instead of the routing table 200.
The control unit 121 controls the entire relay router 120 and executes desired route control with reference to the extended routing table 210 and the policy table 220 if necessary. When a packet flows into the relay router, the control unit 121 first searches the extended routing table 210 and then searches the policy table 220 as necessary.
The receiving unit 122 receives a packet.
The transfer unit 123 transfers the packet traffic.
For convenience of description of the function, the relay router is described as being divided into the relay router 120 and the relay router 12, but a part or all of the relay router 12 in the network may be used as the relay router 120.

[Routing Table 200]
FIG. 4 is a diagram illustrating a configuration example of the routing table 200.
The routing table 200 is a table-like data structure (database) that holds a list of routes to individual network destinations. The routing table 200 is a general table that holds the destination address of the device that is the next destination on the route for reachable destinations. In the present embodiment, the routing table 200 is referred to by the POIs 11 and 110, the relay router 12, and the edge router 13 in the network during routing and transfer control.

The routing table 200 holds the destination address of the device that is the next destination on the route for reachable destinations as described below.
As illustrated in FIG. 4, the routing table 200 sets a destination item 201 and an action item 202 corresponding to the destination item 201. The destination item 201 includes a Global DA and a network prefix. When the destination address is Global DA, the action item 202 is a “next hop” as a next destination on the route. When the destination address of the destination item 201 is an in-network prefix, the action item 202 is a router that is the next destination in the network. For example, the intra-network prefix 1 is a router 3 and the intra-network prefix 2 is a router 4. The routing table 200 holds the processing contents of one flow processed by one router with one entry (corresponding to one line in FIG. 4).
The routing table 200 is used as a forwarding information base (FIB) that is optimized by being compressed and converted into a form that can be easily stored and referenced by hardware. The FIB is a smaller table that collects only route information used in a routing algorithm for route selection. The router has an architecture in which a control plane function corresponding to the routing table 200 and a transfer plane function corresponding to the FIB are separated.

[Extended routing table 210]
The extended routing table 210 sets all the route control addressed to the intra-network prefix, and sets the destination address and the transfer destination or the designation of the table to be referred to. The extended routing table 210 sets all the route controls addressed to the intra-network prefix. Therefore, in the extended routing table 210, when there is no corresponding destination on the extended routing table 210, the destination is other than the intra-network prefix.
FIG. 5 is a diagram illustrating a configuration example of the extended routing table 210.
The extended routing table 210 is a route table obtained by extending the general routing table 200 and has the following characteristics. The extended routing table 210 is described in the present embodiment for the first time by the present inventors.
The extended routing table 210 is referred to by the relay router 120 during routing and transfer control. As will be described later, the order of reference of the extended routing table 210 is also characteristic.

The extended routing table 210 sets a destination address and a transfer destination thereof or a designation of a table to be referred to.
Specifically, as illustrated in FIG. 5, the extended routing table 210 sets a destination item 211 and an action item 212 corresponding to the destination item 211. The destination item 211 includes Global DA, network prefix, and default. When the destination address is Global DA, the action item 212 is “Next hop” which is the next destination on the route, and in addition to the normal forwarding destination designation, the table designation to be referred to “Forward” And set. That is, the extended routing table 210 includes a table designation “Forward” to be referred to in addition to the normal forwarding destination designation “Next hop” in the action item 212 of the destination address.
When the destination address of the destination item 211 is an intra-network prefix, the action item 212 sets a router that is the next destination in the network. For example, the intra-network prefix 1 is a router 3 and the intra-network prefix 2 is a router 4.
When the destination address of the destination item 211 is “default”, the action item 212 sets a table “Policy table” to be referred to.
As described above, the extended routing table 210 can specify a table to be referred to in addition to the normal transfer destination designation in the action item 212, and if there is no corresponding destination in the destination item 211 (default) If applicable, the action is determined by referring to the policy table 220. The extended routing table 210 is obtained by extending the function of the routing table 200 for this route control.

[Policy table 220]
FIG. 6 is a diagram illustrating a configuration example of the policy table 220.
The policy table 220 sets conditions for packets to be controlled and their transfer destinations.
Specifically, as illustrated in FIG. 6, the policy table 220 sets a definition policy item 221 and an action item 222 corresponding to the definition policy item 221. The definition policy item 221 includes Condition, transmission source = end user belonging to the connection provider A, and transmission source = end user belonging to the connection provider B. For example, when the definition policy item 221 is Condition, the action item 222 is Local DA. When the definition policy item 221 is an end user belonging to the transmission source = connection operator A, the action item 222 is POI (GWR). When the definition policy item 221 is an end user belonging to the transmission source = connection provider B, the action item 222 is the router 4.
The PBR distributes various types of traffic for each designated route in accordance with a policy table 220 that defines policies (specific rules). The PBR can implement a routing policy that allows or denies a path based on a specific end system ID, application protocol, or packet size. The policy is based on, for example, an IP address, a port number, or a protocol. Further, as shown in FIG. 6, source-dependent routing is possible.

The operation of the routing system configured as described above will be described below.
[Overall operation]
<Routing system 100A>
In the routing system 100A, the address block information assigned to the end user 4 in the concentrator network 1 is advertised and exchanged via the BGP protocol. Then, the POI 110 advertises the default route in the network using the BGP protocol, and further, the relay router 12 including the relay router 120 has an extended routing table 210 to transfer the packet to the POI 110 when the destination is not the network address. Is set.

<Routing system 100B>
In the routing system 100 </ b> B, the route server 10, which is different from the concentration provider network 1, centrally manages address block information and in-network default route information assigned to the end users 4 in the concentration provider network 1. The route information is distributed from the route server 10 to the relay router 12 including the relay router 120 in the concentrator network 1, and the extended routing table 210 of the relay router 120 and the routing table 200 of the relay router 12 are set.

[Control sequence]
FIG. 7 is a control sequence diagram of the routing systems 100A and 100B shown in FIGS.
As shown in FIG. 7, the end user 4 has a connection provider A and a connection provider B addressed to the Internet. For example, the connection operator A is the end user 4 ₁ (see FIGS. 1 and 2), and the connection operator B is the end user 4 ₂ (see FIGS. 1 and 2).
The connection provider A transmits traffic to the Internet via the concentrator network 1 (see step S101).
(Edge router 13, for example, FIGS. 1 and 2 ₁₎ edge router 13 in the network receives a traffic transmission from the end user 4 (end users _{4 1)} (see step S102), the edge router 13 (edge router 13 ₁ ), the transfer unit (not shown) transfers the traffic to the relay router 120 (see step S103). Hereinafter, the operation of the relay router 120 will be described.

<Relay router 120 traffic reception>
The receiving unit 122 (see FIG. 3) of the relay router 120 receives the traffic transmission from the edge router 13 (edge router 13 ₁ ) (see step S104).

<Extended routing table 210 search>
The control unit 121 (see FIG. 3) of the relay router 120 first searches the extended routing table 210 and performs destination determination (see step S105). The destination determination performed by searching the extended routing table 210 is as follows.
That is, when a packet flows into the relay router 120, the control unit 121 first determines whether or not there is a corresponding destination on the extended routing table 210. If there is a corresponding destination on the extended routing table 210 (Yes in step S105), the process proceeds to step S106, and if there is no corresponding destination on the extended routing table 210 (No in step S105), step S107 (in the policy table 220). Go to Search.
As described above, since the extended routing table 210 sets all the route control addressed to the intra-network prefix, if there is a corresponding destination on the extended routing table 210, the route control addressed to the intra-network prefix can be performed. Good.
If there is a corresponding destination on the extended routing table 210 (Yes in step S105), the destination is sent to the transfer unit 123 (see FIG. 3) in order to perform traffic forwarding to an appropriate relay router (see step S106). .

On the other hand, in the destination determination of step S105, if there is no corresponding destination on the extended routing table 210, the table “Forward” (see FIG. 5) to be referred to is searched. As a result, the destination address “default” of the destination item 211 (see FIG. 5) of the extended routing table 210 is searched, and the table “Policy table” to be referred to is referenced from the action item 212 (see FIG. 5). The
Here, when there is no corresponding destination on the extended routing table 210, this corresponds to a case where the destination is a full route. At this time, all users are mixed in the transmission source.

<Policy table 220 search>
As described above, the route table reference order refers to the extended routing table 210 first, and refers to the policy table 220 only when there is no corresponding destination on the extended routing table 210 (when the destination is a full route). Therefore, when the destination is an intra-network prefix in the extended routing table 210, the policy table 220 is not referred to.
As shown in FIG. 7, the control unit 121 (see FIG. 3) of the relay router 120 refers to the policy table 220 only when there is no corresponding destination on the extended routing table 210. The control unit 121 searches the policy table 220 and performs destination determination (see step S107).

<Relay router 120 traffic forwarding>
In the case of FIG. 7, it is determined that the connection provider A is not the traffic transmission addressed to the Internet and the connection operator A is the traffic transmission addressed to the Internet. When the destination determination is not satisfied (No in Step S107), the transfer unit 123 (see FIG. 3) of the relay router 120 forwards traffic to the connection operator A dedicated POI (GWR) (see Step S108). In the case of the routing systems 100A and 100B shown in FIGS. 1 and 2, the connection operator A dedicated POI (GWR) is a POI 110 whose position has been changed (added).
The connection operator A dedicated POI (GWR) (POI 110) receives the traffic transfer from the relay router 120 (see step S109).

<Extended routing table 210 search>
On the other hand, in the destination determination in step S105, if there is a corresponding destination on the extended routing table 210, the destination is transferred to an appropriate relay router according to the destination (see step S106).

<Relay router 120 traffic forwarding>
Further, in the destination determination in step S107, when this destination determination is satisfied (Yes in step S107), the transfer unit 123 (see FIG. 3) of the relay router 120 performs traffic to the address in step S106 or step S107. Transfer (see step S110).

  The other relay router 12 receives the traffic transmission from the relay router 120 (see step S111), and forwards it to an appropriate relay router according to the destination (see step S112).

[Route table settings and route search]
FIG. 8 is a diagram for explaining the state of each route table setting and route search. FIG. 9 is a setting example of the extended routing table 210 in the case of each route table setting and route search of FIG. Note that the policy table 220 (see FIG. 6) is not changed.
8 and 9, for convenience of explanation, the relay router 120 is referred to as router 1, and the relay router 12 under the relay router 120 is referred to as router 2, router 3, and router 4. The router 4 is a relay router that receives the traffic transfer from the relay router 120. The connection operator A dedicated POI (GWR) is the POI 110 whose position has been changed (added).
As shown in FIG. 9, in the extended routing table 210, Global DA, network prefix under router 1, network prefix other than router 2, and default are set as destination items 211, and the action items corresponding to each are set. As “212”, “Next hop” / “Forward”, router 3, router 4, and “Policy table” are set. Further, in the policy table 220 shown in FIG. 6, Condition, transmission source = connection operator A, transmission source = connection operator B are set as the destination item 221, and Local DA, POI (GWR) and router 4 are set.

The routing system according to this embodiment performs route control in an autonomous and distributed manner based on information in a route table (routing table, extended routing table, policy table). As shown in FIG. 8, when a packet flows into the router 1, the router 1 first searches the extended routing table 210 (see FIG. 9).
As shown in the second and third entries of the extended routing table 210 (see FIG. 9), when there is a corresponding destination on the extended routing table 210 (that is, a network prefix under the router 1 and a network other than under the router 2) In the case of the internal prefix), the traffic is forwarded to the routers 3 and 4 as indicated by the symbols i and j in FIG.

  As shown in the Global DA of the first entry of the extended routing table 210 (see FIG. 9), when there is no corresponding destination on the extended routing table 210, the table designation “Forward” to be referred to is searched. As a result, the destination address “default” of the destination item 211 (see FIG. 9) of the extended routing table 210 is searched, and the table “Policy table” to be referred to is referenced from the action item 212 (see FIG. 9). The By referring to the policy table 220 (see FIG. 6), the route is determined by the PBR according to the transmission source. In the configuration example of the policy table 220 (see FIG. 6), when the transmission source = the end user belonging to the connection carrier A, traffic is transferred to the POI (GWR) as indicated by the symbol k in FIG. Further, in the case of the end user belonging to the transmission source = the connection carrier B, traffic is forwarded to the router 4 as indicated by reference numeral 1 in FIG.

FIG. 15 is a table showing verification of each route table size of the relay router A before and after the POI change with respect to the specifications of the commercial device. FIG. 15 shows a comparison between the number of entries in the routing table (as viewed in FIB) and the policy table (as viewed in ACL) after the POI change in this embodiment and the comparative example.
When the routing table (FIB) is compared in this embodiment and the comparative example, the number of entries (12000 entries) in the extended routing table 210 (see FIG. 6) of this embodiment and the number of entries in the routing table 200 (see FIG. 4). (12000 entries) is almost the same. Incidentally, the number of entries in the routing table of the commercial device specifications is 5 million.

  On the other hand, the number of entries in the policy table of the commercial device specifications is 250,000. This embodiment and the comparative example are compared by the number of entries after the POI change for the specifications of the commercial device. In the case of <Comparative example (1)>, the number of entries in the policy table reaches 62 million entries, for example, and cannot be realized with the commercial device specifications. In addition, even in the case of <Comparison Example (2)> in which the policy table description method is devised, the number of entries is 720,000 entries, which cannot be handled by the category of commercial devices (25 entries). In contrast, in the present embodiment, the policy table 220 after the POI change (for example, the position change of the POI 110 shown in FIGS. 1 and 2) has 120 entries, and <Comparison Example (1)> and <Comparison Compared with Example (2)>, it can be significantly reduced (1 / 1,000,000), and it is possible to cope with commercial equipment specifications as shown by the circle (circle) in the table of FIG. .

As described above, the routing systems 100A and 100B (see FIGS. 1 and 2) according to the present embodiment include the POI 110 with the Internet connection operator network 3 and the concentration operator network 1 in the concentration operator network 1. The relay router 120 connected to the POI 110 or another router, and the edge router 13 connecting the end user to the relay router 120 or another router, the relay router 120 controls the route to the prefix in the network. An extended routing table 210 (storage unit) (see FIG. 5) that sets all, sets a destination address, its transfer destination, a table to be referred to, and a table to be referenced (see FIG. 5), and is a control target. Policy table 220 (storage unit) (see FIG. 6) for setting packet conditions and transfer destinations, and packet inflow Case, first, searches the extended routing table 210, and when there is a specification of table to be referred, a control unit 121 for reference sequence control table to find the policy table 220 (see FIG. 3), the.
The control unit 121 searches the policy table 220 when the destination of the incoming packet corresponds to the specification of the table to be referred to on the extended routing table 210. In addition, when there is a corresponding destination on the extended routing table 210, the control unit 121 performs route control for the in-network prefix.

  In the comparative example, the policy table 220 (see FIG. 6) is referred to and then the routing table 200 (see FIG. 4) is referred to. Therefore, the number of entries in the policy table 220 increases explosively (FIG. 15). There is a problem that it is referred to). On the other hand, in this embodiment, the extended routing table 210 of the relay router 120 sets the destination address, the transfer destination, and the designation of the table to be referenced. When the extended routing table 210 is searched and a table to be referred is specified, the reference order of the table to be searched for the policy table 220 is controlled. Therefore, the search itself to the policy table 220 is drastically reduced as compared with the comparative example in which the policy table 220 is uniformly searched. In other words, first, the extended routing table 210 is searched, and the policy table 220 is searched for the first time when a table to be referenced is specified. Therefore, the number of entries in the policy table 220 is significantly reduced (1 / 1,000,000). can do. As a result, desired route control can be realized by avoiding destination designation in policy-based routing, which is a bottleneck. As shown by the circles (circles) in the table of FIG.

Of the processes described in the above embodiment, all or part of the processes described as being performed automatically can be performed manually, or the processes described as being performed manually can be performed. All or a part can be automatically performed by a known method. In addition, the processing procedures, control procedures, specific names, and information including various data and parameters shown in the above-described document and drawings can be arbitrarily changed unless otherwise specified.
Further, each component of each illustrated apparatus is functionally conceptual, and does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each device is not limited to that shown in the figure, and all or a part thereof may be functionally or physically distributed or arbitrarily distributed in arbitrary units according to various loads or usage conditions. Can be integrated and configured.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Further, each of the above-described configurations, functions, and the like may be realized by software for interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function is stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), an IC (Integrated Circuit) card, an SD (Secure Digital) card, an optical disk, etc. It can be held on a recording medium.

1 Concentrator network 2 Internet
4, 4 ₁ to 4 ₆ End user 3, 3 _{1 to} 3 ₃ Internet connection carrier network 10 Route server 11, 11 _{1 to} 11 ₃ , 110 POI (GWR)
12, 12 _{1 to} 12 ₅ Relay router (other routers)
13, 13 _{1 to} 13 ₃ Edge router 100A, 100B Routing system 120 Relay router 121 Control unit 122 Receiving unit 123 Transfer unit 200 Routing table 210 Extended routing table (storage unit)
220 Policy table (storage unit)

Claims (7)

In a concentrator network connecting the end user and the Internet connection operator network, a full route indicating all route information on the Internet or a network indicating address block information assigned to the end user in the concentrator network A routing system that performs route control by policy-based routing using one of the internal prefixes,
POI (Point Of Interface) which is a gateway for connecting the concentrator network and the Internet connection provider network;
A relay router connected to the POI or another router in the network operator network;
An edge router connecting the end user and the relay router or another router, and
The relay router is
An extended routing table for setting all the route control addressed to the intra-network prefix and setting a destination address, its forwarding destination, and a table to be referred to, and conditions of the packet to be controlled and its forwarding destination A storage unit for storing a policy table for setting
A routing unit comprising: a control unit that searches the extended routing table when a packet flows, and controls a reference order of the table for searching the policy table when a table to be referred to is specified. system. The controller is
The routing system according to claim 1, wherein when the destination of the incoming packet is on the extended routing table, route control for the intra-network prefix is performed. The controller is
The routing system according to claim 1, wherein when there is a corresponding destination on the extended routing table, route control for the intra-network prefix is performed. The routing system according to claim 1, wherein the route control in the concentrator network is route control in an AS (Autonomous System). Address block information assigned to the end user in the network operator network is advertised / exchanged via the BGP protocol, and the POI is advertised with a default route in the network using the BGP protocol, and further includes a router including the relay router. The routing system according to claim 1, wherein the extended routing table is set to forward a packet to the POI when the destination is not an in-network address. The address block information and network default route information assigned to the end user in the network operator network are centrally managed by an independent server or router having a route information management function different from the network operator network. The routing system according to claim 1, wherein route information is distributed from the server or router to a router including the relay router in the concentrator network, and an extended routing table of the relay router is set. . In the concentrator network connecting the end user and the Internet connection operator network, the full route indicating all route information on the Internet or the address block information assigned to the end user in the concentrator network A routing method for a routing system that performs route control by policy-based routing using one of prefixes,
POI (Point Of Interface) which is a gateway for connecting the concentrator network and the Internet connection provider network;
A relay router connected to the POI or another router in the network operator network;
An edge router connecting the end user to the relay router or other router,
The relay router is
An extended routing table for setting all the route control addressed to the intra-network prefix and setting a destination address, its forwarding destination, and a table to be referred to, and conditions of the packet to be controlled and its forwarding destination A storage unit for storing a policy table for setting
A routing method characterized in that when a packet flows in, first, the extended routing table is searched, and when a table to be referred to is specified, the reference order of the table for searching the policy table is controlled.

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