JP2003333088A - Packet transfer system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a packet transfer system, in which a user's own packets can be sent to a destination in regular sequence based on time, regardless of the presence of the other users' packets, when a plurality of users send packets to the same destination. <P>SOLUTION: A classifier indicating the violation of an agreement is selectively incorporated into each of packets having a corresponding traffic quantity exceeding the quantity specified in the agreement, among the packets inputted into a first core router 106<SB>1</SB>, and then the packets are stored in an input buffer (not shown) with each corresponding to an input port in an input order. Of the packets stored in the head of each of the input buffer, the packets having no classifier are sent out preferentially. Accordingly, the packets having a traffic quantity not exceeding the quantity specified in the agreement can be sent out more preferentially than the packets, inputted in another port, having a traffic quantity exceeding the quantity specified in the agreement. Also, the packets inputted in the same buffer can be sent out in the regular sequence in terms of the time. <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 a packet transfer system, and more particularly, to a packet transfer system in which the amount of outflow of packets is limited by a contract when switching the packets by a switch such as an edge router.

[0002]

2. Description of the Related Art An IP (Internet Protocol) network has become a base for providing not only conventional data communication but also services for various communication applications such as telephone and video streaming. In addition, as the number of services using the IP network increases, it may be required to transfer packets whose total amount exceeds the capacity of the transmission path. In preparation for such a case, the characteristics and service level of the communication application, that is, Q
It is considered that a packet within a traffic volume secured in advance is preferentially transferred in accordance with a request of oS (Quality of Service).

[0003] As an example of a technique for providing a service of preferentially transferring packets in this way, there is a Diffserv (Differentiated service). DiffServ is an Internet Engineering Task Force's "RFC (R
equest For Comment) 2475 ". Generally, when using DiffServ, a service provider and a user who use this service make a contract for service contents in advance. Next, a packet transfer system that preferentially transfers packets will be described by taking DiffServ as an example.

FIG. 12 is a simplified representation of a network to which DiffServ is applied as a packet transfer system. The network 11 is provided with a core router 12 that transfers packets and first and second edge routers 13 ₁ and 13 ₂ that transfer packets input to the network 11 to the core router 12. These first and second edge routers 13 ₁ and 13 ₂ respectively have a packet identifying unit 14 ₁ or 1 ₁ as a classifier for identifying the QoS class of the input packet.
4 ₂ and policers 15 ₁ and 15 ₂ for discriminating whether or not the traffic volume is within the contract volume, and markers 16 ₁ and 16 ₂ for replacing the identification value of the packet according to the discrimination result of the corresponding policer. Here, the contract volume refers to the traffic volume that is predetermined by the contract.

The operator of the network 11 and the user who desires to use the network 11 make a service level agreement (SLA) in advance.
This service contract includes the QoS class contracted by the user and the traffic amount which is the amount of packets sent to the network 11 per unit time. The operator of the network 11 delays each contracted QoS class,
It is specified to provide the quality of service for transfer, which is composed of jitter, packet loss rate, etc. Further, the operator of the network 11 provides the quality of service as long as the user sends the traffic amount of packets up to the contracted amount to the network 11.

[0006] Next, a related operation will be described with respect to a packet transmitted from a user who has a service contract. After making a service contract with the operator of the network 11, the user sends a packet to the network 11 from a packet sending device (not shown). The packets sent to the network 11 are input to the first or second edge routers 13 ₁ and 13 ₂ . Here, the packet transmitted to the first edge router 13 ₁ will be described. First, a DSCP (Diffserv Code Point) value, which is an identification value for identifying the contracted QoS class, is added to the packet header in the packet identification unit 14 ₁ . This packet is then policer 1
It is input to 5 ₁ to measure the traffic volume, and as policing, it is determined whether or not the traffic volume is within the contract volume. If the traffic volume exceeds the contract volume,
A value indicating a policing violation is added to the DSCP value added to the packet header of the packet exceeding the marker 16 ₁ . A packet for which a value indicating a policing violation has not been added passes policing. The packet added with the value indicating the policing violation is preferentially discarded when congestion occurs in the network 11. The core router 12 controls packet transfer according to the priority according to the QoS class indicated by the DSCP value assigned by the first edge router 13 ₁ in this way.

[0007] FIG. 13 shows a traffic input to a conventional router.
Here is an example of the amount of traffic and the amount of traffic output.
It is a thing. Switch 21 for distributing packets
Has on its input side a first and a second input port 2
Two₁, 22₂However, the output port 23 is arranged on the output side.
ing. The switch 21 provided in the router is for each input port.
To 22₁, 22₂Switch connections to output port 23 evenly
Round-robin scheduling to give you the opportunity to continue
Shall be performed. In addition, the first input port 22 ₁To
The first user connecting has a maximum traffic volume of 2.4 G
Contracted for bps (Giga byte per second)
With a service contract with a volume of 1.8 Gbps
The second input port 22₂Second user connecting to
Also has a maximum traffic volume of 2.4 Gbps
Signed a service contract with a contract volume of 0.6 Gbps
I'm supposed to be out. Further, it can be output from the output port 23
It is assumed that the maximum traffic amount is 2.4 Gbps.

Here, a packet having a traffic amount of 1.8 Gbps is continuously input from the first user to the first input port 22 ₁ , and the second input port 22 ₂ is input from the second user. Traffic volume is 1.
Consider a case where 2 Gbps packets are continuously input. In this case, a packet having a total amount of 3.0 Gbps is input to the output port 23.
Of the packets input by the second user, 0.6 Gbps within the contract amount is a packet that has passed policing, and 0.6 Gbps indicated as the remaining traffic amount 26.
s is a packet in violation of policing.

However, when the switch 21 allocates the packets input from the first and second input ports 22 ₁ and 22 ₂ to the output port 23 by the round robin method, the respective input ports 22 ₁ and 22 ₂ . Packets of 2 Gbps each are output to the output port 23.
As a result, among the packets input by the first user, the packets passing the policing of 0.6 Gbps indicated as the traffic amount 27 are blocked by the packets of the policing violation of 0.6 Gbps input by the second user. It As a result, there arises a problem that the first user cannot guarantee the transfer of the packet with the contracted amount defined by the service contract.

In order to solve such a problem, there is required a technique for adjusting the scheduling of the switch so that the packet which has passed the policing is preferentially connected to the switch which has the violation of the policing. To this end, JP-A-2000-324168 or JP-A-20-324168
There is a technique described in 01-298477.

FIG. 14 is for explaining the conventional core router shown in these publications. Core router 3
1 is a first to Pth not shown (P is an integer of 2 or more).
The _{first to} Pth input buffers 32 _{1 to} 32 _P respectively corresponding to the packets input from the respective input ports and the first to Qth (Q is an integer of 2 or more) output ports 33 _{1 to} 33 _Q. It is equipped. In addition, the first to Pth input buffers 32
_A scheduler 34 that adjusts the connection relationship between ₁ to 32 _P and the _{first to} Qth output ports 33 _{1 to} 33 _Q , and a scheduler 3
4 is provided with a switch 35 for making these connections.

The _{first to} Pth input buffers 32 _{1 to} 32 _P have the same circuit configuration. Therefore, the first input buffer 32 ₁ will be described as a representative.

In the first input buffer 32 ₁ , a first output port addressed high priority queue 36 _1H for queuing a packet having a high output priority among the packets transmitted from the first output port 33 ₁ and an output Low-priority queue 36 _1L addressed to the first output port for queuing low-priority packets
Is provided. Thus the queue corresponding to the height of each priority to the output ports 33 ₁ ~ 33 _Q destined first to Q are provided. Furthermore, for these queues, the first
The packet distribution unit 37 that distributes the packet input from the input port and the packet transmission unit 38 that extracts the packet from each queue and sends the packet to the switch 35. As described above, the packets input to the core router 31 are queued in the queues provided in the _{first to} Pth input buffers 32 _{1 to} 32 _P corresponding to the combinations of the output ports and the priorities. It has become so.

[0014] JP-A-2000-324168 Patent Publication the indicated techniques, to the scheduler 34, the request 39 ₁ ~ 39 _P notification showing the output priority of packets stored from each queue requesting switch connection To be done.
Scheduler 34, based on the request 39 ₁ ~ 39 _P, the scheduling like for switching connection of a higher priority queue priority.

In the technique disclosed in Japanese Patent Laid-Open No. 2001-298477, the first to Pth input buffers 32 are provided.
_{When a} certain number of packets addressed to the same output port are accumulated for each _{1 to} 32 _P , a request for switch connection 39 ₁
~ 39 _P is notified to the scheduler 34. The scheduler 34 performs scheduling so that the output ports do not overlap, and notifies the grants 40 ₁ to 40 _P indicating output permission to the corresponding input buffer. The first to P-th input buffers 32 _{1 to} 32 _P are adapted to preferentially read packets from the corresponding high priority queue for the output port according to the grants 40 ₁ to 40 _P. By queuing packets that pass policing as priority packets and packets that violate policing as non-priority packets by priority, it is possible to preferentially send packets that pass policing.

[0016]

[Problems to be Solved by the Invention]

By the way, the packet that has passed policing and the packet that has violated policing are obtained by distinguishing the packets received from the same user and sent to a predetermined destination simply in relation to the contracted amount. Therefore, considering a case where a user transfers a series of data constituting one application program as a packet, a part of the data is distributed to packets that pass policing,
A situation occurs in which the remaining data is distributed to packets that violate policing. Japanese Patent Laid-Open No. 2000 mentioned above
-324168 or JP 2001-2984 A
In the technique described in Japanese Patent Publication No. 77, packets that pass policing and packets that violate policing are queued in different queues, so that packets for the contracted amount can be preferentially transferred. For this reason, when these techniques are simply applied, a packet in which a policing violation occurs may be transferred in a later order than a packet in which the policing has passed. This causes a situation in which a part of the application program that should originally be received as a series of data is sent to the destination before the rest.

When the packet transfer order is changed in this way, the data is reproduced after the packet receiving side that receives the policing violation transferred later is received. Therefore, it may cause the received application program to not operate properly. Even for data such as telephone and video streaming that requires real-time processing, if the packet transfer order is changed, the quality of the data to be reproduced deteriorates and it becomes meaningless as data.

Therefore, an object of the present invention is that when a plurality of users send packets to the same destination, their packets are sent to the destination in a timely order regardless of the presence of packets of other users. To provide a packet transfer system.

[0020]

According to the first aspect of the invention, (a) the packet outflow amount per unit time is defined from a plurality of inflow side transmission lines in which the packet inflow amount per unit time is respectively defined. The packet receiving means for receiving the packets destined for the same common outgoing transmission path, and (b) the packet per unit time among the packets received by the packet receiving means through the respective incoming transmission paths. An identifier adding means for selectively adding an identifier to the inflowing packet so as to distinguish the amount of outflow exceeding the amount secured in advance for each inflow side transmission and the amount having no arrangement for securing from the amount secured in advance. (C) The individual packets after the identifiers are selectively added by the identifier adding means are stored on a first-come-first-served basis for each of a plurality of inflow side transmission lines. A packet storage means provided, (d) check the packet position retrieving next respectively stored in these packet storage means, within the packet outflow amount per unit time of the outlet-side transmission line,
A packet extracting unit that preferentially extracts a packet in which an outflow amount per unit time is secured by an identifier for each unit time, and (e) a packet transmitting unit that transmits the packet extracted by the packet extracting unit to an outflow side transmission line. And the packet transfer system.

That is, according to the first aspect of the present invention, when receiving packets from a plurality of inflow side transmission lines to the same outflow side transmission line common to them, the identifier adding means determines the outflow amount per unit time. An identifier is added to the packet so that the amount secured in advance for each inflow side transmission line can be distinguished from other amounts. Here, the identifier may be added to the amount of outflow per unit time with respect to the amount secured in advance for each inflow side transmission line,
Other than this may be used. In addition, in the transmission path where it is arranged that the outflow amount per unit time is secured in advance for each inflow side transmission path, the one that is secured and the one that is not secured are distinguished by the identifier, but there is no arrangement for securing the transmission path. Packets flowing in from are treated as something other than the amount secured in advance. The individual packets after the identifiers have been selectively added by the identifier adding means are stored in the packet storage means provided corresponding to each of the plurality of inflow side transmission lines in the order of arrival. Then, the packet extracting means checks the packets stored in the packet storing means at the positions to be extracted next,
Within the range of the packet outflow amount per unit time of the outflow side transmission line, the packet whose outflow amount per unit time is secured by the identifier is preferentially taken out every unit time. Therefore, the packet extraction means preferentially extracts the packets for which there is an arrangement for securing from the respective packet storage means within the range of the packet outflow amount per unit time of the outflow side transmission line. Packets for which the outflow amount per unit time has been secured are preferentially extracted. At this time, paying attention to the respective packet storage means, packets are extracted on the so-called first-in first-out principle. For this reason, the packets that have flowed into each of the inflow side transmission lines are sequentially extracted in time order and sent to the outflow side transmission line, which avoids the inconvenience of being out of order.

According to the second aspect of the present invention, (a) a plurality of inflow-side transmission lines in which the packet inflow amount per unit time is defined, respectively, and the packet outflow amount in the unit time is specified, which are the same in common. Packet receiving means for respectively receiving the packets directed to the outgoing transmission path,
(B) Among the packets received by the packet receiving means and passed through the respective inflow side transmission lines, the amount of the outflow amount per unit time that exceeds the amount secured in advance for each inflow side transmission line is secured in advance. Identifier adding means for selectively adding an identifier to the inflowing packet so as to distinguish it from (c)
Packet storage means provided corresponding to each of the plurality of inflow side transmission lines, which stores the individual packets after the identifiers are selectively added by the identifier addition means, respectively, and (d) these packet storage means Check the packet at the next extraction position stored in the packet and check the packet for which the outflow amount per unit time is secured by the identifier within the range of the packet outflow amount per unit time on the outflow side transmission line. In addition, the packet transfer system is provided with the packet extracting means for preferentially extracting and (e) the packet transmitting means for transmitting the packet extracted by the packet extracting means to the transmission path on the outgoing side.

That is, according to the second aspect of the present invention, when receiving packets from a plurality of inflow side transmission lines to the same outflow side transmission line common to them, the identifier adding means determines the outflow amount per unit time. An identifier is added to the packet so that the amount secured in advance for each inflow side transmission line can be distinguished from other amounts. Here, the identifier may be added to the amount of outflow per unit time with respect to the amount secured in advance for each inflow side transmission line,
Other than this may be used. The individual packets after the identifiers have been selectively added by the identifier adding means are stored in the packet storage means provided corresponding to each of the plurality of inflow side transmission lines in the order of arrival. Then, the packet extraction means checks the packet at the next extraction position stored in each of these packet storage means, and within the range of the packet outflow amount per unit time of the outflow side transmission line, the packet extraction unit The packets whose outflow amount has been secured are preferentially taken out every unit time.
Therefore, the packet extraction means preferentially extracts the packets for which there is an arrangement for securing from the respective packet storage means within the range of the packet outflow amount per unit time of the outflow side transmission line. Packets for which the outflow amount per unit time has been secured are preferentially extracted. At this time, paying attention to the respective packet storage means, packets are extracted on the so-called first-in first-out principle. For this reason, the packets that have flowed into each of the inflow side transmission lines are sequentially extracted in time order and sent to the outflow side transmission line, which avoids the inconvenience of being out of order.

According to the third aspect of the present invention, (a) the same packet transmission amount per unit time is defined by a plurality of inflow side transmission lines and the same packet transmission amount per unit time is common. Packet receiving means for respectively receiving the packets directed to the outgoing transmission path,
(B) Among the packets received by the packet receiving means and passed through the respective inflow side transmission lines, the amount of the outflow amount per unit time that exceeds the amount secured in advance for each inflow side transmission line is secured in advance. Identifier adding means for selectively adding an identifier to the inflowing packet so as to distinguish it from (c)
Packet storage means provided corresponding to each of a plurality of inflow side transmission paths for respectively storing the individual packets after the identifiers have been selectively added by the identifier adding means, and (d) inflow side transmission path Extraction priority registration means for registering the priority when the packets extracted from these packet storage means compete for extraction for each
(E) A packet in which the outflow amount per unit time is secured by the identifier within the range of the packet outflow amount per unit time of the outflow side transmission line by checking the packet at each head position stored in the packet storage means Between the packets for which the outflow amount per unit time is secured when the packets are preferentially fetched for each unit time, the packet fetching unit that preferentially fetches the packet having the high fetching priority registered in the fetching priority registering unit. (F) The packet transfer system is provided with a packet sending means for sending the packet taken out by the packet taking means to the outgoing transmission path.

That is, according to the third aspect of the present invention, when receiving packets from a plurality of inflow side transmission lines to the same outflow side transmission line common to them, the identifier adding means determines the outflow amount per unit time. An identifier is added to the packet so that the amount secured in advance for each inflow side transmission line can be distinguished from other amounts. Here, the identifier may be added to the amount of outflow per unit time with respect to the amount secured in advance for each inflow side transmission line,
Other than this may be used. The individual packets after the identifiers have been selectively added by the identifier adding means are stored in the packet storage means provided corresponding to each of the plurality of inflow side transmission lines in the order of arrival. By the way, according to the present invention, the extraction priority registration means registers the high extraction priority of the packet stored in the packet storage means via the inflow side transmission path corresponding to each inflow side transmission path. There is. Then, the packet extraction means checks the packet at the next extraction position stored in each of these packet storage means, and within the range of the packet outflow amount per unit time of the outflow side transmission line, the packet extraction unit Packets for which the outflow amount has been secured will be preferentially taken out every unit time.
Due to the outflow amount per unit time, there is a case where a plurality of packet storage means conflict with each other for extraction. At this time, the one having a high priority registered in the extraction priority registration means is preferentially taken out.

According to the invention described in claim 4, (a) packet receiving means for respectively receiving packets destined for the same outgoing transmission line in which the sending amount of packets per unit time is defined for each sending source. (B) a transmission source discriminating means for discriminating the transmission source of the packet received by the packet receiving means, and (c) a unit time of the packets discriminated to be the same transmission source by the transmission source discriminating means. Identifier adding means for selectively adding an identifier to the received packet so as to distinguish the amount in which the transmission amount per unit exceeds the amount secured in advance for each transmission source from the amount secured in advance; and (d) this identifier Packet storing means provided corresponding to each transmission source for storing individual packets after the identifiers have been selectively added by the adding means, on a first-come-first-served basis; Check each packet at the beginning position stored in the packet storage means, and check the packets whose outflow amount per unit time is secured by the identifier within the range of the packet outflow amount per unit time on the outflow side transmission line. The packet transfer system is provided with a packet extracting means for preferentially extracting each packet and (f) a packet transmitting means for transmitting the packet extracted by the packet extracting means to the outgoing transmission path.

That is, in the invention described in claim 4, the packet received from the inflow side transmission line is divided for each transmission source,
The identifier adding means selectively adds an identifier according to the outflow amount secured according to each transmission source. The packets are stored in the packet storage means provided according to the transmission source, and the packets secured in advance from these are preferentially transmitted. Since the packets are stored in the packet storage means for each transmission source and taken out in the storage order, the order is not changed in the reception order and the transmission order.

According to a fifth aspect of the present invention, in the packet transfer system according to the second or third aspect, the identifier adding means has a unit time out of the packets received by the packet receiving means through the respective inflow side transmission paths. The feature is that an identifier is added to a portion in which the outflow amount per hit exceeds the amount secured in advance for each inflow side transmission line.

That is, in the invention as set forth in claim 5, an identifier is added to the packets of which the outflow amount per unit time exceeds the amount secured in advance for each inflow side transmission line.

[0030] In the invention according to claim 6, in the packet transfer system according to claim 2 or claim 3, the identifier adding means has a unit time out of the packets received by the packet receiving means through the respective inflow side transmission paths. The feature is that an identifier is added to the amount of outflow per hit that is secured in advance for each inflow side transmission line.

That is, in the invention as set forth in claim 6, an identifier is added to the packets for which the outflow amount per unit time is secured in advance for each inflow side transmission line.

[0032]

DETAILED DESCRIPTION OF THE INVENTION

[0033]

EXAMPLES The present invention will be described in detail below with reference to examples.

First embodiment

FIG. 1 shows an outline of an IP network which constitutes a packet transfer system in the first embodiment of the present invention. The IP network 101 includes first to third access networks 102 _{1 to} 102 3 which are networks in a relatively narrow range, and these first to _third access networks.
The core network 103 connected to the access networks 102 _{1 to} 102 ₃ is arranged. First to third
Access network 102 _{1-102 3} of, for example, points to the network, such as to connect with each home device using distribution networks CATV (cable television).
The core network 103 refers to a network created by, for example, a telephone company using high-speed lines that connect cities. First to third access networks 1
02 _{1 to} 102 ₃ respectively include the core network 103.
It is the first to third customer premises equipment (CPE) 104 ₁ ~104 ₃ for transmitting and receiving packets are provided between the. The core in the network 103, first to third edge router 105 for transmitting and receiving the first to third packets directly to the customer premises equipment 104 _{1-104 3} respectively
₁ to 105 _3, the first and second core router 10 that performs transfer processing of packets in the core network 103
6 ₁ and 106 ₂ are provided.

FIG. 2 shows the structure of the core router arranged in the core network shown in FIG.
Here, the first core router 106 ₁ will be described, but the second core router 106 ₂ has the same configuration, and thus the description thereof will be omitted. The first core router 106 ₁ is provided with first to Nth (N is an integer of 2 or more) input ports 111 ₁ which are respectively connected to transmission lines through which packets flow.
And - 111 _N, and a pre-processing unit 112 ₁ to 112 _N of the first to N for performing pre-processing of an inputted packet, the input buffer 113 ₁ to 113 _N of the first to N is provided .
Further, a switch 114, a scheduler 115 that schedules the switch 114, the output port 116 ₁ -116 _M first to M respectively connected to the transmission path on the outflow side of the packet (M is an integer of 1 or more.) Is provided. The first core router 106 ₁ further includes a control unit 127.
Is equipped with. The control unit 127 is a CPU (not shown).
A central processing unit is provided, and this processing unit controls each unit in the _first core router 106 ₁ in accordance with a program also stored in a storage medium (not shown). Further, the control unit 127 is supplied with the clock signal 129 from the clock signal generator 128. In this way, the first core router 106 ₁ has the first to Nth input buffers 113 ₁ to ₁ 1 in the preceding stage of the switch 114.
It is configured as an input buffer type switch provided with 13 _N.

First to Nth input buffers 113 _{1 to} 11
3 _N have the same circuit configuration. Therefore, the first input buffer 113 ₁ will be described as a representative. The first input buffer 113 _1, output and port addressed queue 117 ₁ ～117 _M first to M provided corresponding to each output port, destined these output port queues 1
Packet distributor 1 that distributes packets to 17 _{1 to} 117 _M
18 and queues for these output ports 117 ₁ to 117 _M
A packet sending unit 119 that takes out a packet from the beginning of the packet and sends the packet to the switch 114 is provided. Further, the first to M header checking unit 120 _1-12 of corresponding to the output port addressed queue 117 ₁ ～117 _M one-to-one of the first to M
0 _M and the first to Mth output port addressed queues 117 _{1 to} 11
A buffer control unit 121 for selecting one of 7 _M is provided. The first to Mth output port addressed queues 117
_{1 to} 117 _M are the first to Mth output ports 116, respectively.
Virtual Output Queue (VOQ) for Virtual Output Port of FIFO (First In First Out) for storing packets sent from _{1 to} 116 _M
Is.

The packet distribution unit 118 is configured to receive the _first packet corresponding to the destination of the packet input to the _first input buffer 113 1.
Queues to the M-th output port addressed queues 117 ₁ to 117 _M. At this time, if the destinations are the same, they are queued in the same output port destination queue 117 ₁ to 117 _M in the input order regardless of whether the policing has passed or passed. Further, in this embodiment, the first to Mth output port addressed queues 117 ₁ to
When 117 _M queues up to the storage limit of the packet distribution unit 118, further packets are not input and are discarded.

The first to Mth header inspection units 120 _{1 to} 12
The 0 _M inspects the header of the packet stored at the head of the corresponding queues 117 ₁ to 117 _{M for} the _{first to} Mth output ports. From the first to Mth header inspection units 120 _{1 to} 120 _M , the respective inspection results are set as the first to Mth inspection result information 122 _{1 to} 122 _M ,
The buffer control unit 121 is notified. The inspection result information 122 _{1 to} 122 _M includes information indicating whether or not a packet is queued, and if queued, whether or not an identifier indicating a policing violation is further incorporated in the header of the first packet. It contains information that indicates The buffer control unit 121 notifies the scheduler 115 of the output port requesting the connection to the switch 114 and the request 123 ₁ indicating the connection priority. Here, the connection priority information indicates information on either policing success or policing violation, which is incorporated in the header of the packet. Also, the grant 124 ₁ indicating the output port that is permitted to connect to the request 123 ₁ is received, and the selected queue information 12 indicating the output port addressed queues 117 ₁ to 117 _M corresponding to the grant 124 _1.
5 is notified to the packet transmission unit 119.

The scheduler 115 receives the first to Nth inputs.
Buffer 113₁~ 113_NRequest 1 notified from
23₁~ 123_NTo receive. And
The received request is sent to the first to Mth output ports 116.₁
~ 116_MSeparately, each has the highest connection priority
Connection to the input buffer that notified the request
Notify the grant that indicates the permitted output port. here
There are two connection priority levels: pass policing and violate policing.
Therefore, passing the policing is given a higher priority. Well
Request 123₁~ 123_NHighest priority of
Are sent to the same output port.
If you like to choose one in a round robin fashion
Has become. The clock signal 129 is selected as the output port.
Based on a time slot based on
It First to Nth input buffer 113 ₁~ 113_NAnd the first
~ Mth output port 116₁~ 116_MConnection relationship is determined
Then, the connection setting information 126 indicating this connection relationship is switched.
The switch 114 is notified. Switch 114 received
According to the connection setting information 126, the first to Nth input buffers
A 113₁~ 113_NAnd the first to Mth output ports 116₁
~ 116_MSet to connect.

FIG. 3 shows the structure of the first preprocessing section shown in FIG. First to Nth preprocessing unit 112
_{1 to} 112 _N have the same circuit configuration.
Therefore, the first preprocessing unit 112 ₁ will be described as a representative. The first preprocessing unit 112 ₁ sends a Q
Packet identification unit 131 for providing identification information of the oS class
And a policer 132 for determining whether or not the inflow amount of packets, which is the traffic amount, is within the contract amount. In addition, a marker 133 that incorporates the determination result of the policer 132 into the packet, and the output port 11 that transmits the packet
6 _{1 to} 116 _M , an output port determination unit 134, and a packet division unit 13 that divides a packet into a predetermined length or less.
5 is provided. The policer 132 includes a storage medium (not shown) for storing the contract amount.

For the packet input from the input port 111 ₁ , the corresponding QoS class is first discriminated by the packet discriminating unit 131, and the DSCP value for discriminating the discriminated QoS class is added to the header of the packet. It has become so. Next, the policer 132 checks whether or not the inflow amount of packets received as policing is within the contract amount. For example, check the packet by storing it in the first-in, first-out buffer that discharges all the packets stored for each unit time in the order of input, and distinguishing the packets from the beginning up to the number according to the contract amount and the packets exceeding it. I do. If the contract quantity is exceeded, a marker 133 is added to the excess quantity of packets, and an identifier indicating a policing violation is added to the DSCP value, resulting in a policing violation packet. A packet whose marker DCP value is not attached with an identifier indicating a policing violation in the marker 133 is a policing pass packet. The packet in which the result of policing is reflected is output to the first core router 106 by the output port determination unit 134.
It is determined from which _one of the output ports 116 _{1 to} 116 _M the packet is transmitted, and information indicating this is added to the packet header. Finally, the packet division unit 135
Then, divide the packet so that it is less than the specified length,
It is sent from the _first preprocessing unit 112 ₁ . Note that when this division is performed, the information incorporated in the packet header is copied and incorporated in each of the divided packets.

FIG. 4 shows the structure of the buffer control unit provided in the first input buffer shown in FIG. The buffer control unit 121 stores the inspection result information 12
An inspection result information receiving unit 141 that receives 2 _{1 to} 122 _M ,
A request creation unit 142 that creates a request 123 ₁ based on the received inspection result information and a request notification unit 143 that notifies the created request 123 ₁ to the scheduler 115 are provided. Also, the buffer control unit 1
21 includes a grant receiving unit 144 that receives the grant 124 ₁ sent from the scheduler 115, a queue selecting unit 145 that selects an output port-destined queue that sends a packet based on the grant 124 ₁ , and a selected output. The selection queue information notification unit 146 that notifies the packet transmission unit 119 of the selection queue information 125 indicating the port-destined queue.
Is provided.

The request creating unit 142 determines the desired connection destination output port indicating the output port to which the packets queued in the inspection result information 122 _{1 to} 122 _M are destined and the connection priority indicating the priority of the packet. A request 123 ₁ incorporating the degree is created. When there are multiple output port queues in which packets are queued, information is incorporated in that number to make one request 123 ₁
May be created. In this case, the connection priority is indicated for each desired connection destination output port. Also,
When the grant receiving unit 144 receives the grant 124 ₁ , the queue selecting unit 145 selects _one of the _first to Mth output port addressed queues 117 ₁ to 117 _M corresponding thereto. Assuming that this is the first output port-destined queue 117 ₁ , the packet transmission unit 119 determines that the first
The packet is taken out from the head of the output port destination queue 117 ₁ and sent to the switch 114. Scheduler 11
No. 5 notifies the connection setting information 126 in time for the packet sending unit 119 to send a packet to the switch 114, and sets the connection between the corresponding input buffer and output port. Thus, the packet 147 ₁ sent from the packet transmitting unit 119 to the switch 114, and is transmitted from the output port corresponding through the switch 114.

Next, how a packet is input to the core router 106 ₁ and transmitted will be described. The first input port 111 ₁ shown in FIG. 2 is connected to the first access network 102 ₁ via the first edge router 105 ₁ shown in FIG.
Packets are input from. See also FIG.
Then, a packet is input to the second input port 111 _{2 (not} shown) from the second access network 102 ₂ via the second edge router 105 ₂ shown in FIG. It is assumed that the operator of the core network 103 has a service contract with a contract amount of 1.8 Gbps with the operator of the _first access network 102 ₁ . Further, it is assumed that a service contract with a contract amount of 0.6 Gbps is made with the operator of the second access network 102 ₂ . From the first output port 116 ₁ up to 2.
It is assumed that packets of 4 Gbps can be transmitted. Here, it is assumed that the packets transmitted from the first output port 116 ₁ are only the packets input from the operators of the first and second access networks 102 ₁ and 102 ₂ . This makes the first
As long as packets are input from the respective operators of the second access networks 102 ₁ and 102 ₂ with a total traffic volume of 2.4 Gbps, all the input packets are the first output port regardless of the contracted amount. 116 ₁
Sent from.

FIG. 5 shows an example of a state in which packets to be sent to the first output port compete for sending in the core router shown in FIG. A 1.8 Gbps packet indicated by a traffic amount 151 from the _first access network 102 ₁ is continuously input to the first input port 111 ₁ .
Since this traffic amount 151 is within the contracted amount, these packets are all packets that have passed policing. Second
Input port 111 ₂ of 1.2 Gbp indicated by the traffic amount 152 from the _second access network 102 _2.
Packets of s are continuously input. Since this traffic volume 152 exceeds the contracted volume, the packet with the traffic volume of 0.6 Gbps that is exceeded is a packet in violation of policing and is given an identifier. A packet with a traffic volume of 0.6 Gbps within the contracted volume is a packet that has passed policing.

In the core router 106 ₁ , packets that pass policing are sent to the switch with priority over packets that have violated policing. This allows
Since all the packets input from the first input port 111 ₁ have passed policing, these are preferentially transmitted from the first output port 116 ₁ . A packet input from the second input port 111 ₂ is sent out from the first output port 116 ₁ by 0.6 Gbps including a policing pass and a policing violation. Further, in the packet input from the second input port 111 ₂ , the traffic volume 0.
The 6 Gbps packet is discarded. Traffic volume 15
Since the packets within 2 are queuing the policing pass packet and the policing violation packet in the same queue in the input order, the discarded packet may include the policing pass packet. However, at least the packet having the traffic amount 152 can be transmitted from the first output port 116 ₁ without changing the input order from the _second input port 111 ₂ . In this example, the first and second access networks 102 ₁ ,
The case has been described in which packets of fixed traffic volumes are input from 102 ₂ . However, for example, when the traffic volume of the packet input from the first access network 102 ₁ fluctuates, the packets of the traffic volume 153 can be transmitted by the margin of the traffic volume on the output port 116 ₁ side.

As described above, the core router 106 ₁ preferentially transfers the policing pass packet when conflicting with the policing violation packet, thereby preferentially forwarding the contracted amount of packets constituted only by the policing pass packet. be able to. This prevents a policing violation packet of another input port from blocking a policing pass packet of its own input port, and can reduce the unfairness of the output opportunity between the input ports. When the output ports are the same, the policing pass packet and the policing violation packet are queued in the same queue in the input order. As a result, the order of packets transmitted from the same output port among packets input from the same input port will not be changed. Also, even if packet drop occurs,
Packets that cannot be queued in the queue are discarded, so even if there is a gap between a series of packets, the order is not changed.

Second embodiment

FIG. 6 shows a part of a core router which constitutes a packet transfer system in the second embodiment of the present invention. In this figure, the same parts as those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. Also in this embodiment, FIG. 1 of the first embodiment is appropriately used. The first core router 106A ₁ is provided with first to Nth input ports 111 _{1 to} 111 _N to which packets are input, and first to Nth to add identifiers indicating connection priority to the input packets. Pre-processing units 201 _{1 to} 201 _N and first to Nth input buffers 202 ₁ that temporarily store the input packets.
.About.202 _N are provided. Further, a switch 114 for outputting side of the selective connection between the input side, an output port 116 ₁ -116 _M first to M which is a transmission destination of the packet,
Depending on the connection priority of the packets stored in the _first to Nth input buffers 202 _{1 to} 202 _N , the switch 114
A scheduler 203 is provided for scheduling the connections of the above. Further, the first to Nth input buffers 202 ₁
-202 _N is the first that incorporates information indicating the connection priority
Scheduler 2 to N-th request 204 ₁ ~204 _N of
03 will be notified. In the second embodiment,
The description will be made assuming that the 103 operators of the core network support a plurality of QoS classes of class 1 to class X (X is an integer of 2 or more) like DiffServ.

FIG. 7 shows the structure of the first preprocessing section shown in FIG. In this figure, the same parts as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The first preprocessor 201 ₁ has a first input port 1
DSCP for identifying the user who is the source of the packet input from 11 ₁ and the QoS class contracted with the user
User class identification unit 211 that adds a value to a packet
When, the first to fourth policer 212 _{1-212 4} corresponding respectively to the user performing the policing traffic volume, first to incorporating selectively packet header identifiers corresponding to policing violations each of these Fourth marker 213
_{1 to} 213 ₄ are provided. 1st-4th policer 21
2 _{1 to} 212 ₄ and the first to fourth markers 213 _{1 to} 21
3 _4, and it is provided to correspond respectively to the first to fourth user. Further, in the first pre-processing unit 201 _1, and an output port determination section 134 to determine the output port to which the destination of the packet, the packet dividing unit 135 for dividing a packet into predetermined following lengths are provided . The packets input from the first input port 111 ₁ are the first to fourth packets for which a service contract has been previously signed with the operator of the core network 103.
Sent from the user. First to fourth policers 212
_{1 to} 212 ₄ and the first to fourth markers 213 _{1 to} 213 ₄
Polices whether or not the traffic volume from the first to fourth users is within the contract volume, and the packets that exceed the contract volume are given an identifier indicating a policing violation.

FIG. 8 shows the structure of the first input buffer shown in FIG. In this figure, the same parts as those in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.
The first input buffer 113 ₁ stores the packets prepared for each combination of the output port and the supported QoS class in the _{11th to} XMth queues 221 _{11 to} 22.
1 _XM , a packet distributor 118 that distributes packets to these queues, and a packet transmitter 119 that extracts the packet stored at the head of these queues and sends it to the switch 114. Here queue 221
The ones digit value of the subscript number attached to the subscript indicates the corresponding output port, and the ones digit value indicates the corresponding QoS class. In addition, the first to XMth queues 22
1 ₁₁ to 221 _XM and eleventh XM header checking unit 222 ₁₁ to 222 _XM for inspecting head packet in a one-to-one correspondence
And a buffer control unit 223 for selecting one from the _{11th to} XMth queues 221 _{11 to} 221 _XM .

The packet distributor 118 receives the packets input by the first to fourth users from the first preprocessor 201 ₁
It has another output of the processing result based on the port and the queue 221 ₁₁ to 221 _XM the eleventh XM which is prepared by QoS classes as queues. The _{11th to} XMth header inspection units 222 _{11 to} 222 _XM correspond to the corresponding _{11th to 11th} XM header inspection units 222 _{11 to} 222 _XM .
The presence or absence of packets queued in the XMth queues 221 _{11 to} 221 _XM is inspected. If the packet is queued, it is inspected whether the identifier indicating the policing violation is added to the first packet. The header inspection units 222 _{11 to} 222 _XM are configured to notify the buffer control unit 223 of this inspection result as inspection result information 122 _{11 to} 122 _XM . The buffer control unit 223 uses the request 2 which is a connection request to the switch 114 created based on the inspection result information 122 _{11 to} 122 _XM.
04 ₁ is notified to the scheduler 203. On the other hand, when the grant 124 ₁ indicating any _{one of} the output ports 116 _{1 to} 116 _N permitted to connect is received, the packet sending unit 119 is notified of the selection queue information 125.

FIG. 9 shows the structure of the buffer controller shown in FIG. In this figure, the same parts as those in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The buffer control unit 223 has inspection result information 122 _{11 to} 122.
Inspection result information reception unit 141 that receives _XM, and request creation unit 2 that creates request 204 ₁ based on this
31 and a request notifying unit 143 for notifying the scheduler 203 of the request 204 ₁ . Also, the grant receiving unit 144 that receives the grant 124 ₁ from the scheduler 203, and the
The switch 114 from the queues 221 _{11 to} 221 XM of the XMth _XM
The packet selection unit 232 includes a queue selection unit 232 that selects a queue from which a packet to be transmitted to the server is selected, and a selection queue information notification unit 146 that notifies the packet transmission unit 119 of the selected queue information 125 indicating the selected queue. Further, it is provided with a priority order table 233 which stores the priority order of connection priorities according to a combination of QoS class and policing pass or policing violation. The request creation unit 231 and the queue selection unit 232 refer to the priority order stored in the priority order table 233 when determining whether the connection priority level is high or low.

Unlike the first embodiment, the request creating unit 231 creates the request 204 _{1 in} consideration of not only the policing pass or the policing violation but also the priority order among the QoS classes. For example, a packet policing passing the output ports 116 ₁ addressed have 11 and 21 of queue 221 _11, 221 ₂₁ stores each combination of the second QoS class and policing pass the first QoS class and policing The case where the priority is set higher than the combination of passing will be described. In this case, since the combination of the second QoS class and the policing pass has a higher priority, the connection to the output port 116 ₁ incorporating the connection priority registered in the priority order table 233 accordingly is connected. A request 204 ₁ for requesting is created. The queue selecting unit 232, in accordance with the grant 124 ₁ received by the grant receiving unit 144, the _11th to XMth queues 221 ₁₁ to.
A queue for extracting a packet to be sent from the 221 _{X M} to the switch 114 is selected. As an example, when the grant 124 ₁ indicates that connection to the output port 116 ₁ is permitted, the _{11th to} 1Mth queues 221 ₁₁ addressed to the output port 116 ₁ are given.
221 Selects the queue storing the packet with the highest connection priority among the packets stored at the head position of _1M . The queue selecting unit 232 acquires the latest inspection result information from the inspection result information receiving unit 141 for this selection. And the queue selection unit 2
When 32 selects the 1M-th queue 221 _1M, for example, a packet is extracted from the head of this 1M-th queue 221 _1M and sent to the switch 114. The scheduler 203 notifies the connection setting information 126 in time for the packet sending unit 119 to send the packet to the switch 114, and sets the connection between the corresponding input buffer 202 ₁ and output port 116 ₁ . . Therefore, the packet sending unit 119
Packet 147 ₁ sent to the switch 114 from,
The data is transmitted from the corresponding output port 116 ₁ via the switch 114.

FIG. 10 shows the configuration of the scheduler shown in FIG. The scheduler 203 includes a request receiving unit 241 that receives requests 204 _{1 to} 204 _N sent from the _{first to} Nth input buffers 202 _{1 to} 202 _N , and a temporary request for each of the first to Xth QoS classes. a first through X request storage unit 242 ₁ ~242 _X of the class-specific request distribution unit 243 for distributing the received request to these are provided for to store. The priority order table 244 stores the priority order of the connection priority according to the combination of the QoS class and the policing pass or the policing violation, and is stored in the _{first to} Xth request storage units 242 _{1 to} 242 _X. An output port 116 ₁ connected to each of the input buffers 202 _{1 to} 202 _N based on the priority order of the request and the connection priority.
An output port selection unit 245 for selecting ~ 116 _M is provided. Further, based on the selection of the output port selection unit 245, a grant that creates any one of the grants 124 _{1 to} 124 _N as the output ports 116 _{1 to} 116 _M that are permitted to connect in accordance with the respective input buffers 202 _{1 to} 202 _N. The creating unit 246 and the grant 1 created by the grant creating unit 246
A grant notification unit 247 which notifies the 24 ₁ to 124 _N to each of the input buffers 202 ₁ to 202 _N, output port selection section 24
The connection information creating unit 248 that creates connection information indicating the connection setting of the switch 114 based on the selection of 5, and the connection information 126 created by the connection information creating unit 248 are stored in the switch 114.
A connection information notification unit 249 for notifying the user is provided.

The output port selection unit 245 refers to the connection priority stored in the priority order table 244,
And to select the output port 116 ₁ -116 _M in order from the request stored in the first through X of the request storage unit 242 ₁ ~242 _X corresponding to high connection priority QoS class. The output port selection unit 245 includes a list indicating the input buffers 202 _{1 to} 202 _N and the output port 1
Each holds a list showing 16 _{1 to} 116 _M ,
Input buffers 202 _{1 to} 202 _N not selected in these lists
And output ports 116 _{1 to} 116 _M are selected one by one to determine the connection relationship. At this time, the input buffer 202 ₁ With to 202 _N and the output port 116 ₁ -116 _M SELECTED_COUNT selected ones of the selection output ports 116 ₁ -116 _M to one input buffer plurality simultaneously Can be prevented. The grant creating unit 246 selects _one of the input buffers 202 _{1 to} 202 _N
Grants 124 _{1 to} 12 that notify the selected output ports corresponding to the corresponding output ports 116 _{1 to} 116 _M
It is designed to create 4 _N.

Among the connection priorities stored in the priority order tables 233 and 244, the packet in violation of policing is given the lowest priority regardless of the priority order of the QoS class. Since the connection priority is determined by the priority order stored in these priority order tables 233 and 244, by changing this setting, an arbitrary priority order can be set. Next, a case where packets of a plurality of QoS classes conflict with each other will be described.

FIG. 11 shows an example of a state in which the packets to be sent to the first output port compete with each other in the core router described in the second embodiment. Here, the first input port 111 ₁ and the second input port 111 ₁
The first of the packets input to the input port 111 ₂ of
What is output to the output port 116 _{1 of the above} will be described. From the first input port 111 ₁ , a 0.4 Gbps packet indicated by the first QoS class traffic amount 251 and a 1.0 Gbps packet indicated by the second QoS class traffic amount 252 are continuously provided. Has been entered in. From the second input port 111 ₂ , the second
0.6 Gb indicated by the traffic volume 253 of the QoS class of
The packets for ps and the packets for 0.8 Gbps indicated by the traffic amount 254 of the third QoS class are continuously input. A packet of up to 2.4 Gbps can be transmitted from the first output port 116 ₁ . Connection priority between QoS classes is 1st
Is the highest, followed by the second and third QoS classes. In addition, the connection priority of the packet with the policing violation identifier indicating the packet in excess of the contract amount determined according to each of the first to fourth users is the lowest connection priority regardless of the QoS class. Is set to.

The packet of the second QoS class inputted from the first input port 111 ₁ is composed of a policing pass packet of 0.6 Gbps and a policing violation packet of 0.4 Gbps. The first QoS class packet input from the first input port 111 ₁ and the second Q class packet input from the second input port 111 _2.
Each of the packets of the QoS class and the third QoS class is composed only of the policing pass packet.

In the core router 106A ₁ , the packets having the higher connection priority are preferentially transmitted to the switch 114. However, the first input port 111 ₁
The second QoS class packet input from the
Depending on the connection priority of packets queued at the head of the queue 221 _21, there is a case where priority is reversed. Here, in order to simplify the problem, among the packets of the second QoS class input from the first input port 111 ₁ , the policing pass packets are biased to the head of the queue and to the back. The description will be made assuming two states.

First, the first input port 111₁Input from
Policing out of second QoS class packets
The pass packet is the 21st queue 221._{twenty one}Biased toward the beginning of
The case will be explained. In this case, the connection priority is the highest
First input port 111₁First QoS input from
The class packet is sent out first. And then connect
Higher first and second input ports 111₁, 11
1₂Policing rate of the second QoS class input from
0.6 Gb evenly distributed by round-robin method
It is sent out every ps. After this, the first input port 11
1₁Policing difference of the second QoS class input from
Anti-packet and second input port 111 ₂Entered from
Packets that have passed the third QoS class policing
Remaining. Packets that violate policing have the highest connection priority
Because the degree is set low,
Packets for 0.8 Gbps are output first. with this
Packets with a total traffic volume of 2.4 Gbps are output.
Therefore, the first input port indicated by traffic 255
111₁Remaining out of the second QoS class input from
That 0.4 Gbps of packets are being discarded
Become.

Next, a description will be given of a case where the policing-passed packets among the packets of the second QoS class input from the first input port 111 ₁ are biased toward the rear of the queue. In this case, the queue 2 that stores the packet of the second QoS class input from the first input port 111 _1.
21 ₂₁ has the lowest connection priority because the policing violation packet is stored at the head thereof. Therefore,
The second QoS input from the first input port 111 _1.
Packets other than the class are first sent in order according to the connection priority. Finally the first input port 1
0.6 Gbps of the second QoS class packet input from 11 ₁ is output, and the remaining 0.4 Gb is output.
Packets for ps are discarded.

As described above, the third QoS having the connection priority lower than that of the policing passing traffic of the second QoS class.
Packets that pass S-class policing are passed to the second QoS.
Packets that violate class policing can be sent without being blocked. Therefore, in the core router 106A ₁ of the second embodiment, a plurality of Qo having different connection priorities are used.
Even when the S class is supported, the same effect as that of the first embodiment can be realized.

In the first and second embodiments described above, the core router 106 ₁ or the core router 106A ₁ is provided with the control unit 127, which controls according to the program. However, the clock signal 12
Alternatively, each unit may be configured by hardware synchronized with 9.
Further, the first to Mth output port addressed queues 117 _{1 to} 11
Of 7 _M and eleventh XM queue 221 ₁₁ to 221 _XM
May be provided as physically independent storage media, or may be provided as a virtual partition of an appropriate number of storage media.

Further, in the first and second embodiments, the identifier of the policing violation is selectively incorporated in the packet input from the relationship between the traffic volume and the contract volume. However, the traffic volume is not specified in the service contract, and the policing violation identifier may be always incorporated in the packet from a specific user. If you include only the identifier of the policing violation, the packet input from that user will be transferred using the band after transferring other packets with high transfer priority, regardless of the traffic volume, When congestion occurs, the amount of packets that can be transferred is often limited. For example, a service contract that is relatively cheaper than a service contract that defines a contract amount may be made with a user who uses conventional data communication that does not have a high demand for transfer speed.

Further, in the second embodiment, for example, if the traffic volume is secured in the same amount as the maximum traffic volume per unit time on the outflow side and a contract is made with the user to set the connection priority to the highest level, in the event of a disaster, etc. It is also possible to prepare a service contract suitable for securing the communication with the highest priority.

Possibility of modification of the invention

In the first or second embodiment, the input packet is divided into either the policing pass or the policing violation based on the contracted amount. In order to identify this, in the first and second embodiments, an identifier indicating a policing violation is incorporated in the packet.
You may make it incorporate the identifier which shows policing pass. Further, the priority may be further divided among the policing passed or the policing violation. For example, a service contract defines two traffic volumes, a limit traffic volume (Peak Rate) and an average traffic volume (Committed Rate). Then, the amount less than the average traffic amount is a policing pass packet, the amount more than the average traffic amount and less than the limit traffic amount is the first policing violation packet, and the amount more than the limit traffic is the second policing violation packet. Packets that pass policing in order of increasing connection priority,
As the first policing violation packet and the second policing violation packet, scheduling is performed in descending order of connection priority. This makes it possible, for example, to preferentially output packets input with a traffic volume slightly exceeding the average value from other input ports over packets input with a temporarily maximized traffic volume from one input port. Various services can be provided.

Further, in the first embodiment, the first preprocessing unit 1
The class identification unit 131, the policer 132, and the marker 133 are provided in 12 ₁ . However, these may be provided in the _first edge router 105 ₁ that inputs a packet to the first input port 111 ₁ . Also, the user class identification unit 211 and the first to fourth policers 212 _{1 to} 21 ₁ provided in the _first preprocessing unit 2011 of the second embodiment.
2 ₄ and the first to fourth markers 213 _{1 to} 213 ₄ may also be included in the first edge router 105 ₁ . In this way, the load of the packet transfer process of the first core router 106 ₁ can be reduced by performing the process of adding the identification value indicating the policing violation in the first edge router 105 ₁ across the networks.

Further, in the second embodiment, the buffer controller 2
23 and the scheduler 203 are provided with priority order tables 233 and 244, respectively. However, the combination of QoS class and policing violation or policing pass is associated with linear priority,
This may be incorporated as the connection priority of the request 204 ₁ . This causes the scheduler 203 to
The connection priorities incorporated in the requests 204 _{1 to} 204 _N can be simply compared to perform preferential scheduling. As described above, the scheduler 203 does not have to include the priority order table 244. At this time, in the case of setting the packet having the policing violation to the lowest priority regardless of the QoS class, priority scheduling can be realized by providing the connection priority of (X + 1) stages. Further, in the case of setting the priority of the packet for which the policing is violated and the packet for which the policing is successful for each QoS class, the priority of scheduling can be realized by providing the connection priority of (2 × X) stages. .

[0072]

As described above, claims 1 to 3 are as described above.
According to the invention described above, a packet storage unit is arranged in each of the inflow side transmission lines, and the packets are stored in the first-come-first-served basis in this.
Since we decided to allocate the outflow to the inflow side transmission path among those stored in advance, the packets stored in the packet storage means from each inflow side transmission path are surely sent to the inflow side transmission path in the storage order. The order will not be out of order. Moreover, by setting the superiority or inferiority when extracting the packet from each packet storage means, it becomes possible to transmit the packet according to the priority.

Further, according to the third aspect of the invention, not only the priority of each packet but also the priority of the packet storage means is determined. Therefore, when a conflict occurs when extracting packets from the packet storage means. This can be arbitrated according to the priority, and a more flexible system can be configured.

Further, according to the invention described in claim 4, since the distribution of the packets to the transmission destinations is controlled for each transmission source, the packet of the transmission source which has a plurality of inflow side transmission paths can be also used. You can enforce those restrictions. Moreover, there is an effect that packets of the same transmission source are transmitted without disturbing the order.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of a network in which core routers are arranged in a first embodiment of the present invention.

FIG. 2 is a block diagram showing an outline of a configuration of a first core router in the first embodiment.

FIG. 3 is a block diagram showing a configuration of a first preprocessing unit in the first embodiment.

FIG. 4 is a block diagram showing a configuration of a buffer control unit provided in a first input buffer.

FIG. 5 is a block diagram conceptually showing the relationship between the input traffic volume and the output traffic volume of the first core router in the first embodiment.

FIG. 6 is a block diagram showing an outline of a configuration of a first core router in a second embodiment.

FIG. 7 is a block diagram showing a configuration of a first preprocessing unit in the second embodiment.

FIG. 8 is a block diagram showing the configuration of a first input buffer in the second embodiment.

FIG. 9 is a block diagram showing a configuration of a buffer control unit provided in a first input buffer in the second embodiment.

FIG. 10 is a block diagram showing a configuration of a scheduler according to a second embodiment.

FIG. 11 is a block diagram conceptually showing the relationship between the input traffic amount and the output traffic amount of the first core router in the second embodiment.

FIG. 12 is a block diagram showing an outline of a network in which a conventional core router and edge router are arranged.

FIG. 13 is a block diagram conceptually showing the relationship between the input traffic volume and the output traffic volume of a conventional core router.

FIG. 14 is a block diagram showing a configuration of a conventional core router.

[Explanation of symbols]

101 IP networks 102 _{1 to} 102 ₃ First to third access networks 103 Core networks 104 _{1 to} 104 ₃ First to third customer premises equipment 105 ₁ , 105 ₂ First and second edge routers 106 ₁ , 106 A ₁ 1st core router 106 ₂ 2nd core routers 111 _{1 to} 111 _N 1st to Nth input ports 112 _{1 to} 112 _N , 201 _{1 to} 201 _N 1st to Nth preprocessing units 113 _{1 to} 113 _N , 202 _{1 to} 202 _N 1st to Nth input buffers 114 Switches 115, 203 Schedulers 116 _{1 to} 116 _M 1st to Mth output ports 117 _{1 to} 117 _M 1st to Mth output port destination queues 120 ₁ to 120 _M, 222 ₁₁ ~222 _XM header checking unit 121,223 buffer control unit 127 control unit 132,212 _{1-212 4} policer 133,213 ₁ 213 ₄ marker 221 ₁₁ ~221 _XM eleventh of the XM queue

Claims (6)

[Claims] 1. A packet destined for the same common outgoing transmission line in which the packet outgoing amount per unit time is defined from a plurality of incoming transmission lines in which the packet incoming amount per unit time is defined respectively. Of the packets received by the packet receiving means and the packets received by the packet receiving means through the respective inflow side transmission paths, the amount of outflow per unit time exceeding the amount secured in advance for each inflow side transmission path. And an identifier adding means for selectively adding an identifier to the inflowing packet so as to distinguish the portion for which there is no arrangement for securing from the previously secured portion, and each individual after the identifier is selectively added by this identifier adding means. Packet storage means for storing the packets on a first-come-first-served basis and provided for each of the plurality of inflow side transmission lines, The packet at the beginning position stored in the storage means is checked, and the packet whose outflow amount per unit time is secured by the identifier within the range of the packet outflow amount per unit time of the outflow side transmission line A packet transfer system comprising: a packet fetching unit that preferentially fetches each time, and a packet sending unit that sends the packet fetched by the packet fetching unit to the outgoing transmission path. 2. A plurality of packets destined for the same outflow side transmission line in which a packet outflow amount is defined from a plurality of inflow side transmission lines in which the packet inflow amount per unit time is respectively defined. Of the packets received by the packet receiving means and the packets received by the packet receiving means through the respective inflow side transmission paths, the amount of outflow per unit time exceeding the amount secured in advance for each inflow side transmission path. And an identifier adding means for selectively adding an identifier to the inflowing packet so as to distinguish it from the reserved amount, and the individual packets after the identifier is selectively added by the identifier adding means are stored on a first-come-first-served basis. , Packet storage means provided corresponding to each of the plurality of inflow side transmission lines, and respective head positions stored in these packet storage means Packet is extracted, and the packet whose outflow amount per unit time is secured by the identifier within the range of the packet outflow amount per unit time of the outflow side transmission line is preferentially extracted per unit time. A packet transfer system comprising: means and a packet sending means for sending the packet taken out by the packet taking means to the outgoing transmission path. 3. A packet destined for the same common outgoing transmission line in which the packet outgoing amount is defined from a plurality of incoming transmission lines in which the packet incoming amount per unit time is respectively defined. Of the packets received by the packet receiving means and the packets received by the packet receiving means through the respective inflow side transmission paths, the amount of outflow per unit time exceeding the amount secured in advance for each inflow side transmission path. And an identifier adding means for selectively adding an identifier to the inflowing packet so as to distinguish it from the reserved amount, and the individual packets after the identifier is selectively added by the identifier adding means are stored on a first-come-first-served basis. , Packet storage means provided corresponding to each of the plurality of inflow side transmission lines, and from these packet storage means for each of the inflow side transmission lines The extraction priority registration means for registering the priority when the extraction packets conflict with each other and the packets at the head positions stored in the packet storage means are checked, and Within the range of packet outflow amount, when the packet whose outflow amount per unit time is secured by the above-mentioned identifier is preferentially retrieved per unit time, this retrieval priority is given among the packets whose outflow amount per unit time is secured. And a packet sending means for sending out the packet taken out by the packet taking means to the outgoing side transmission line. Characteristic packet transfer system. 4. A packet receiving means for respectively receiving packets destined for the same outgoing transmission path, in which the amount of packets sent per unit time is defined for each sending source, and the packet receiving means receives the packets. Among the transmission source discriminating means for discriminating the transmission source of the packet and the packet determined to be the same transmission source by the transmission source discriminating means, the transmission amount per unit time is the amount secured in advance for each transmission source. Identifier adding means for selectively adding an identifier to the received packet so as to distinguish the excess amount from the reserved amount, and the individual packets after the identifier is selectively added by this identifier adding means Packet storage means provided corresponding to each of the transmission sources, which are stored in order, and the respective head positions stored in these packet storage means A packet extracting unit that checks packets and preferentially extracts, for each unit time, a packet whose outflow amount per unit time is secured by the identifier within the range of the packet outflow amount per unit time on the outflow side transmission line. And a packet sending means for sending the packet taken out by the packet taking means to the outflow side transmission line. 5. The identifier adding means, out of the packets received by the packet receiving means via the inflow side transmission paths, the outflow amount per unit time exceeds the amount secured in advance for each inflow side transmission path. 4. The packet transfer system according to claim 2 or 3, wherein an identifier is added for each portion. 6. The identifier adding means identifies an identifier of a packet, which is received by the packet receiving means and which has passed through each inflow side transmission path, for which an outflow amount per unit time is secured in advance for each inflow side transmission path. 4. The packet transfer system according to claim 2, wherein the packet transfer system is added.