JP2009194444A - Multicast path specifying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique which specifies multicast path information in real time by using a flow information output function. <P>SOLUTION: A network topology calculation part 102 manages information associating a router identifier of a router, its IF information, router identifiers of routers adjacent to the router, and their IF information with each other, on the basis of MIB information. A multicast path information collection part 104 manages information associating multicast group addresses, the router identifier, and outflow IF information with each other, on the basis of option information of flow information or multicast path information described in flow information. A multicast forwarding path calculation part 105 associates multicast group addresses, the router identifier, its outflow IF information, router identifiers of routers adjacent to the router, and their outflow IF information with each other, on the basis of information managed by the network topology calculation part 102 and information managed by the multicast path information collection part 104. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for specifying a logical forwarding path in multicast traffic and a technique for measuring the amount of traffic flowing on the forwarding path.

  The technique of identifying and drawing the multicast packet transfer path is important in terms of network design and management. For example, grasping where multicast traffic for each multicast group address is replicated and how it is transferred on an actual IP network is very useful for isolation in the event of a network failure. . In addition, it is important to confirm the consistency of the traffic flow according to the actual routing design and to confirm the consistency compared to the traffic amount in terms of confirming the service provision state.

  However, the method of specifying the multicast traffic transfer route is more difficult than the method of specifying the unicast traffic transfer route. In Non-Patent Document 1, by using a multicast trace route function, a route from a multicast receiving terminal side to a multicast distribution terminal is searched in reverse, thereby enabling display of a transfer route. However, this method does not display the result based on the actual traffic, but can specify it by sending and receiving the control packet of the query, request, and response packet for the trace route. For this reason, it is difficult to always display the state of the transfer route of multicast traffic and the amount of traffic flowing therethrough, and it is not suitable for use for the purpose of overlooking the situation based on actual traffic.

  Further, in Patent Document 1, multicast route control information is collected by inquiring the multicast MIB (Non-Patent Document 2) of the router on the multicast distribution terminal side and the router on the multicast reception terminal side, and the route between them is OSPF (Open Shortest). The search method is based on metrics information based on (Path First). In this method, there is a problem that a multicast MIB is installed in the router and a routing protocol of the network depends on OSPF, and there is a problem that applicability is limited. Further, in both Non-Patent Document 1 and Patent Document 1, the transfer route is estimated by performing a reverse search from the multicast receiving terminal side to the multicast distributing terminal for traffic flowing from the multicast distributing terminal to the multicast receiving terminal. This is not in line with the actual traffic flow, so that there is a problem that it is difficult to isolate a problem when a failure occurs in the route information itself.

  For this reason, in order to identify route information according to actual multicast traffic and to look down on the information, a function for identifying in real time is required.

  On the other hand, in recent years, routers equipped with a flow information output function (Non-Patent Documents 3 and 4) have become widespread. The flow information output function aggregates transfer packets into a packet group in which several types of header fields called flows are the same, and outputs the information. The most common flow is a 5-tuple flow in which five sets of values {transmission IP address, reception IP address, transmission port number, reception port number, transport protocol} are the same. At this time, it is becoming common to select a packet that passes a certain observation point and output the flow instead of outputting the flow to all the transfer packets. Based on this flow information, if it becomes possible to identify the multicast traffic forwarding route for each multicast group address, it is possible to grasp the state of the forwarding route based on the actual traffic, and in real time. The service provision status can be grasped.

  It is also considered in Non-Patent Document 5 to specify multicast route information based on this flow output information. Non-Patent Document 5 describes a method for generating a multicast packet flow. In order to be able to specify a multicast path, information on IFs into which packets have flowed in and information on multiple outflow IFs of packets that are duplicated and flow out are necessary. Here, in order to output the inflow IF information and the outflow IF information, it is clearly shown that both the flow information generated from the inflowed packet and the flow information generated by duplication of the packet are output from the router.

  However, in a large-scale network, a router on the multicast receiving terminal side generally accommodates thousands of terminals, and the distribution method described in Non-Patent Document 5 increases the flow information generated by duplication. The load on the flow information receiving apparatus side that receives the flow information and manages it as outflow IF information increases.

H. Asaeda, T. Jinmei, W. Fenner, S. Casner, "Mtrace Version 2: Traceroute Facility for IP Multicast," IETF draft-ietf-mboned-mtrace-V2.00, November 12, 2007. K. McCloghrie, D. Farinacci, D. Thaler, "IPv4 Multicast Routing MIB," RFC2932, October 2000. B. Claise et al "Cisco Systems NetFlow Services Export Version 9," RFC3954, October 2004. B. Claise etal "Specification of the lPFIX Protocol for the Exchange of lP Traffic Flow Information," IETF, draft-ietf-ipfix protocol-26.txt, September 2007 J. Quittek, T. Zseby, B. Claise, S. Zander "Requirements for IP Flow Information Export (IPFIX)," RFC3917, October 2004. Japanese Patent Application Laid-Open No. 2005-64636, “Content Distribution Route Creation Method, Content Distribution Route Consistency Confirmation Method, Method of Estimating User Terminals Affected by Content Distribution, Program for Content Distribution Route Management Device, and Content Distribution Route Management” , Nippon Telegraph and Telephone Corporation

  In the present invention, in view of the above-described problems, it is possible to identify a multicast route information in real time using a flow information output function and indicate the amount of traffic flowing therethrough, thereby making it possible to grasp a service provision state. In addition, the present invention avoids the problem of increasing the load on the flow information receiving apparatus side described in Non-Patent Document 5, and realizes this.

  Of the inventions disclosed in this specification, the outline of typical ones will be briefly described as follows.

  A first invention is a multicast route specifying method in a flow information receiving device that receives flow information and specifies a forwarding route of multicast traffic, wherein the flow information receiving device includes a network topology calculating unit and a multicast route information collecting unit. And a multicast transfer path calculation unit, the network topology calculation unit associates information identifying the router, IF information, information identifying the router adjacent to the router, and the IF information based on the MIB information. The first information is managed, and the multicast route information collecting unit is configured to identify information for identifying multicast traffic and information for identifying a router based on option information of flow information or multicast route information described in the flow information. And the second information that correlates the outflow IF information And the multicast forwarding route calculation unit identifies multicast traffic based on the first information managed by the network topology calculation unit and the second information managed by the multicast route information collection unit. And the information for identifying the router, the outflow IF information, the information for identifying the router adjacent to the router, and the outflow IF information.

  According to a second aspect, in the first aspect, the multicast route information collection unit associates the address including the address of the multicast distribution terminal, and the multicast forwarding route calculation unit associates the address including the address of the multicast distribution terminal. Features.

  According to a third aspect, in the first or second aspect, the information for identifying the multicast traffic is a multicast group address or label information in MPLS.

  In a fourth aspect based on the first to third aspects, the flow information receiving device includes a multicast traffic information collection unit and a drawing unit, and the multicast traffic information collection unit is distributed as flow information. Traffic information is managed, and the drawing unit uses the information from the multicast transfer route calculation unit and the multicast traffic information collection unit to map the traffic amount actually flowing on the specified multicast route from the flow information. It is characterized by displaying.

  In a fifth aspect based on the fourth aspect, the flow information receiving apparatus includes a flow information receiving unit, and the flow information receiving unit includes flow information and multicast route information described in option information or flow information. And transmitting information related to the traffic volume (number of bytes, number of packets, number of lost packets) to the multicast traffic information collection unit, and transmitting multicast route information to the multicast route information collection unit. To do.

  In a sixth aspect based on the fifth aspect, the flow information receiving unit receives distribution of outflow IF information for each multicast group from a flow information relay device that collects information using a flow information output function of a router. It is characterized by that.

  In a seventh aspect based on the first to sixth aspects, the flow information receiving device includes an MIB information inquiry unit, the MIB information inquiry unit inquires MIB information from a router, collects MIB information, The network information is managed based on the third information managed by the MIB information inquiry unit. The first information is created.

  According to the present invention, it is possible to specify a multicast logical route without increasing the load of the flow information receiving apparatus, and to specify the amount of traffic that can flow there. As a result, the network administrator can quickly respond to the provision status of the multicast service, the response when a problem occurs, and the inquiry from the receiving user.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing an example of a basic configuration of a system that implements a multicast route identification method according to an embodiment of the present invention for Internet traffic data. 100 is a flow information receiving device, 110 is a flow information relay device, and 120 is a network (IP network). 101 is an SNMP inquiry unit (MIB information inquiry unit), 102 is a network topology calculation unit, 103 is a flow information reception unit, 104 is a multicast route information collection unit, and 105 is a multicast transfer route calculation unit. Yes, 106 is a multicast traffic information collection unit, and 107 is a Web drawing function (drawing unit). The flow information receiving apparatus 100 includes an SNMP inquiry unit 101, a network topology calculation unit 102, a flow information reception unit 103, a multicast route information collection unit 104, a multicast forwarding route calculation unit 105, a multicast traffic information collection unit 106, and a Web drawing function 107. Prepare. Reference numerals 111 to 116 denote routers arranged in the network 120.

  In the multicast route specifying method of the embodiment of the present invention, it is necessary to grasp the topology information of the network in advance. About this, it implements in the following procedures 1 and 2. In addition, it is assumed that the router is set to output the flow information when multicast traffic flows in.

  1. The SNMP inquiry unit 101 inquires of all routers in the network 120 for MIB (Management Information Base) by SNMP (Simple Network Management Protocol), and uses IF (Interface) index information (IF information) and the IF. Collect the configured network address. Thereby, the following information is managed.

  As shown in Table A, the SNMP inquiry unit 101 manages a router identifier, IF index (IF information), an IP address type, and a network address, which are information for identifying a router.

  Eventually, the SNMP inquiry unit 101 inquires the routers 111 to 116 for MIB information, collects the MIB information, and associates information for identifying the router (router identifier), IF information (IF index), an IP address, and a network address. Manage information.

  2. The network topology calculation unit 102 associates information between neighboring routers based on the information in the table A of the SNMP inquiry unit. This can be determined by the fact that routers having the same network address are adjacent to each other. Thereby, the following information is managed.

  As shown in Table B, the network topology calculation unit 102 manages the router identifier, the IF index of the adjacent router and the IF index of the adjacent router, which is information for identifying the adjacent router.

  Eventually, the network topology calculation unit 102 manages information that associates information that identifies a router, IF information, information that identifies a router adjacent to the router, and IF information based on the MIB information.

  3. The flow information relay apparatus 110 receives flow information distributed by IPFIX and NetFlow protocols. In the flow information, in addition to the five sets of values {transmission IP address, reception IP address, transmission port number, reception port number, transport protocol} that are traffic information, information and packets of IF indexes that flow into and out of the router Number, and the number of bytes. In addition, it may include time information and payload information received by the router.

Here, as described in Non-Patent Document 5, a flow that flows into the IF is distinguished from a flow that is duplicated and flows out from the IF. The outflow corresponds to the case where the egressIF information has a valid value and the ingressIF information is invalid or the ingressIF information does not exist, and the inflow has an ingressIF information with a valid value and an egressIF information with an invalid value This is the case where there is no egressIF information. (If the value is 0, it becomes an invalid value.)
Here, the flow information relay apparatus 110 aggregates the flow information into information (number of bytes, number of packets, number of packet losses) related to traffic per unit time and transmits the information to the flow information receiving apparatus 100. For example, it means that traffic information per unit time is aggregated based on the flow information distributed in units of packets from the router and redistributed to the flow information receiving apparatus 100. It is assumed that the unit time interval is determined by the allowable load of the flow information receiving apparatus and the operator's policy.

  Separately from this, the table C is created based on the flow-in flow and flow-out flow information.

  As shown in Table C, the flow information relay device 110 creates a table of the multicast delivery terminal IP address, multicast group address, router identifier, inflow IF index (inflow IF information), and outflow IF index (outflow IF information). To do.

  Based on the table C created here, multicast route information is transferred to the flow information receiving apparatus 100 as option information. It is assumed that the distribution contents include the information of FIG. 3A shows the cases of IPv4 and IPv6, and FIG. 3B shows the case of MPLS (Multi Protocol Label Swicthing). Here, it is only necessary to include information that becomes the outflow IF index and information that uses Scope as information necessary for routing in order to flow out the information. In FIG. 3A, reference numeral 301 denotes a flow information distribution source router, 302 a multicast group address, 303 an IP address of a multicast distribution terminal, 304 an inflow IF index, and 305 an outflow IF index. In FIG. 3B, 311 is a flow information distribution source router, 312 is mplusTopLabel, 313 is an inflow IF index, and 314 is an outflow IF index. This option information is periodically distributed from the flow relay apparatus 110.

  It is also possible to include multicast route information in the flow information instead of option information. This case is shown in FIG. In FIG. 4, 401 is the multicast group address, 402 is the IP address of the multicast distribution terminal, and 403 is the inflow IF index. Reference numeral 404 denotes an outflow IF index list, which includes information on each outflow IF index as shown in FIG. In FIG. 4B, 411 is the outflow IF index # 1, 412 is the outflow IF index # 2, 413 is the outflow IF index # 3, 414 is the outflow IF index # 4, and 415 is the outflow IF index #N.

  Eventually, the flow information relay apparatus 110 collects information using the flow information output function of the routers 111 to 116, and based on the collected information, the outflow IF information for each multicast group is obtained as the flow information of the flow information receiving apparatus 100. Delivered to the collection unit 103.

  4). The flow information receiving unit 103 of the flow information receiving apparatus 100 receives flow information serving as multicast traffic information and multicast route information transferred as option information (this is the flow information relay apparatus 110 or the direct routers 111 to 116. You may receive from either.) Here, when receiving multicast route information directly from the routers 111 to 116, the routers 111 to 116 have a function of distributing information similar to that of the flow information relay apparatus 110 to the flow information receiving apparatus 100, but “exporterIPv” The information of {4 | 6} Address "may not be present. In this case, it is possible to identify the distribution source router based on the information of the source IP address of the flow distribution protocol (NetFlow, IPFIX). In addition, when it does not depend on the IP address of the multicast distribution terminal, the information of “sourceIPv {4 | 6} Address” may not be present.

  The information received by the flow information receiving unit 103 and related to the route is transmitted to the multicast route information collecting unit 104, and the information related to the traffic is transmitted to the multicast and traffic information collecting unit 106. In the case of transfer in the format of FIG. 4, the multicast group address (label information in the case of MPLS, generally information identifying the multicast traffic) corresponding to the option information, and the IP address of the multicast distribution terminal The outflow destination IF list is transmitted to the multicast route information collection unit 104. The other part related to traffic information is transmitted to the multicast traffic information collecting unit 106. Further, the multicast distribution terminal here may indicate a rendezvous point (RP) set in the network. In that case, the transfer path between the RP and the receiving terminal is specified.

  Eventually, the flow information receiving unit 103 receives the flow information and the multicast route information described in the option information or the flow information, transmits the flow information to the multicast traffic information collecting unit 106, and sends the multicast route information to the multicast route. It transmits to the information collection part 104.

  5). The multicast route information collection unit 104 creates a corresponding “router identifier” and “outflow IF index” table using information corresponding to the Scope field of the option information as key information. Here, the information of the table C is created with reference to the case of the IPv4 address in FIG.

  As shown in Table C, the multicast route information collection unit 104 manages the IP address, multicast group address, router identifier, inflow IF index (inflow IF information), and outflow IF index (outflow IF information) of the multicast distribution terminal. To do.

  Since the Scope field specified in FIG. 3A corresponds to “IP address of multicast distribution terminal” and “multicast group address”, route information is managed using this as key information. Here, when the route information does not depend on the IP address of the multicast distribution terminal (that is, when the “IP address of the multicast distribution terminal” is not included in the Scope field of FIG. 3A), this information is unnecessary. It is good.

  Eventually, the multicast route information collection unit 104 identifies information (multicast group address or label information in MPLS) for identifying multicast traffic based on the option information of the flow information or the multicast route information described in the flow information, and the router Information that associates the information that identifies the information with the outflow IF information is managed.

  6). The multicast transfer route calculation unit 105 configures the following information based on the information in the table C of the multicast route information collection unit 104 and the information in the table B of the network topology calculation unit 102. Based on the information of the “router identifier” and “outflow IF index” in Table C, the “router identifier” and “IF index” in Table B are searched. Collect routers. This is referred to as table D.

  As shown in Table D, the multicast transfer path calculation unit 105 creates a table having the IP address, multicast group address, router identifier, outflow IF index, concatenated router identifier, and adjacent router IF index of the multicast distribution terminal.

  Again, if the route information does not depend on the IP address of the multicast distribution terminal, this information may be unnecessary. Further, router information not included in the router identifier of the table C is deleted from the table D. In the following example, the case of deletion is indicated by a double line.

  As a result, the traffic of the multicast group address (225.0.0.1) distributed from the multicast distribution terminal (IP address = 10.0.0.1) is the router # 1 → router # 3 → router # 4. 5 and 6 can be identified.

  Eventually, the multicast transfer route calculation unit 105 is configured to identify multicast traffic based on information managed by the network topology calculation unit 102 (table B) and information managed by the multicast route information collection unit 104 (table C). Information for identifying a router, outflow IF information, information for identifying a router adjacent to the router, and outflow IF information are associated with each other.

  7. The multicast traffic information collection unit 106 manages traffic information. Since the traffic information distributed as the flow information includes the inflowed IF index, it is confirmed whether this IF index is included in the “adjacent router IF index” of the table D. The Web drawing function 107 uses the information from the multicast transfer route calculation unit 105 and the multicast / traffic information collection unit 106 to mark the drawing in FIG. 2 with “◎” at the point where the traffic information is detected. Thus, drawing is performed so that the consistency between the route information and the traffic information can be determined. Further, the traffic volume is displayed with the thickness of the arrow in the direction of traffic flow. In FIG. 2, 200 is a multicast distribution terminal, 210 is an arrow pointing in the direction of traffic flow, and 220 is one of multicast reception terminals that receive multicast traffic from the multicast distribution terminal 200.

  After all, the multicast traffic information collection unit 106 manages the traffic information distributed as the flow information, and the Web rendering function 107 uses the information from the multicast transfer route calculation unit 105 and the multicast traffic information collection unit 106 to The traffic volume actually flowing on the specified multicast route is mapped from the flow information and displayed.

  The flow information receiving apparatus 100 and the flow information relay apparatus 110 described above can be configured by one or a plurality of computers and programs. Moreover, instead of a part or all of the program, it may be configured by hardware.

  As mentioned above, the invention made by the present inventor has been specifically described based on the above embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Of course.

It is a block diagram which shows the structural example of the apparatus in this invention. It is an image figure of the multicast transfer path | route display screen visualized with the web drawing function of a flow information receiver. It is a schematic diagram of multicast route information transferred as option information (in the case of IPv4 and IPv6). It is a schematic diagram (in the case of MPLS) of multicast route information transferred as option information. It is the schematic of the multicast route information transferred with flow information. It is a figure which shows each egressInterface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Flow information receiving apparatus, 101 ... SNMP inquiry part, 102 ... Network topology calculation part, 103 ... Flow information receiving part, 104 ... Multicast route information collection part, 105 ... Multicast forwarding route calculation part, 106 ... Multicast traffic information collection 107: Web rendering function, 110: Flow information relay device, 111-116 ... Router, 120 ... Network

Claims (7)

A multicast route specifying method in a flow information receiving device for receiving flow information and specifying a forwarding route of multicast traffic,
The flow information receiving device includes a network topology calculation unit, a multicast route information collection unit, and a multicast forwarding route calculation unit,
The network topology calculation unit manages, based on MIB information, first information that associates information identifying a router, IF information thereof, information identifying a router adjacent to the router, and IF information thereof,
The multicast route information collection unit is configured to associate information identifying the multicast traffic, information identifying the router, and outflow IF information based on the option information of the flow information or the multicast route information described in the flow information. 2 information,
The multicast forwarding path calculation unit includes information for identifying multicast traffic and a router based on the first information managed by the network topology calculation unit and the second information managed by the multicast path information collection unit. Associating information identifying the outflow IF information with information identifying a router adjacent to the router and the outflow IF information;
A multicast route identification method characterized by the above. The multicast route identification method according to claim 1,
The multicast route information collection unit associates including the address of the multicast distribution terminal,
The multicast forwarding route calculation unit associates including the address of the multicast delivery terminal,
A multicast route identification method characterized by the above. The multicast route specifying method according to claim 1 or 2,
The multicast route identifying method, wherein the information for identifying the multicast traffic is a multicast group address or label information in MPLS. The multicast route specifying method according to any one of claims 1 to 3,
The flow information receiving device includes a multicast / traffic information collecting unit and a drawing unit,
The multicast traffic information collection unit manages traffic information distributed as flow information,
The drawing unit uses the information from the multicast forwarding route calculation unit and the multicast traffic information collection unit to map and display the traffic amount actually flowing on the specified multicast route from the flow information,
A multicast route identification method characterized by the above. The multicast route specifying method according to claim 4,
The flow information receiving device includes a flow information receiving unit,
The flow information receiving unit receives the flow information and the multicast route information described in the option information or the flow information, transmits information related to the traffic volume to the multicast / traffic information collecting unit, and sends the multicast route information to the multicast route information. Send to the multicast route information collection unit,
A multicast route identification method characterized by the above. The multicast route specifying method according to claim 5,
The flow information receiving unit receives distribution of outflow IF information for each multicast group from a flow information relay apparatus that collects information using a flow information output function of a router. The multicast route specifying method according to any one of claims 1 to 6,
The flow information receiving apparatus includes a MIB information inquiry unit,
The MIB information inquiry unit inquires MIB information from the router, collects MIB information, and manages third information that associates information for identifying the router, IF information, an IP address, and a network address;
The network topology calculation unit creates the first information based on the third information managed by the MIB information inquiry unit.
A multicast route identification method characterized by the above.

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