JP2003258882A - Packet scheduling device, scheduling method, and its program and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent delay and delay variation by identifying a packet by a simple rule and preferentially transferring a real-time communication packet. <P>SOLUTION: In a packet scheduling device comprising a division part 12 for dividing the packet to a designated length and a rate control part 16 for transferring the packet by a designated transfer rate, the packet between real- time communication terminals is identified previously by routing processing. A packet division part 12 divides a packet exceeding a designated length to the designated length, transfers the divided packet to the rate control part 16 and transfers not-divided packet to a packet output part 15 and the not- divided packet is outputted to a line 41 from the packet output part 15. The rate control part 16 transfers the packet to the packet output part 15 by the designated transfer rate. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet scheduling device and a scheduling method for providing high-quality voice communication on an IP network, a program thereof, and a recording medium.

[0002]

2. Description of the Related Art Conventionally, VoIP (Voice over)
In real-time communication such as Internet Protocol), even in a network in which only communication between real-time communication terminals is transferred, non-real-time communication packets such as call control packets transferred between real-time communication terminals transfer data such as voice. Delay variation is applied to the packet. Depending on the length of the call control packet or the like and the line speed, this delay variation becomes large and the quality of real-time communication may deteriorate.

FIG. 3 is a block diagram of a packet scheduling device based on the prior art. This packet scheduling device is provided in a router device that interconnects a LAN and a WAN and performs packet routing.
It divides the packet to be sent to, and transfers it with priority. In the conventional device, in the router device, the packet input unit 11 into which the packet after the routing processing is input, the packet dividing unit 12 that divides the packet into the specified length, and the rule specified by the information included in the packet header are used. QoS based on which packets are distributed to priority and non-priority queues
(Quality of Service) Class distribution unit 13, priority queue 21 and non-priority queue 22
And a packet output unit 15 for transmitting a packet to the network.

In the routing process, which is the first stage of the packet scheduling device, packets between real-time communication terminals are identified in advance according to conditions such as IP addresses.
It is assumed that they are input to the packet input unit 11 of the packet scheduling device. Packets between real-time communication terminals include packets that require real-time characteristics such as voice and video, and packets that do not require real-time characteristics such as call control packets, bandwidth reservation packets, and management packets.

Generally, in order to suppress delay, real-time communication has a small packet length, and non-real-time communication has a large packet length. When the bandwidth of the transmission line is small and the packet of the non-real-time communication affects the delay and delay variation of the real-time communication such as voice and video, the packet dividing unit 12 divides the packet into the designated length, and the QoS. Based on the information included in the packet header, the class allocating unit 13 assigns the real-time communication packet 31 and the non-real-time communication packet 32 to the priority queue 21 and the non-priority queue 2 of the packet queue group 14, respectively.
In this method, the real-time communication packet is divided into two, and the real-time communication packet is preferentially transferred to suppress the delay in waiting for the real-time communication packet to be sent out.

[0006]

As described above, the packets between the real-time communication terminals are those that require real-time characteristics such as voice and video, and call control packets, bandwidth reservation packets, management packets, and other real-time characteristics. Unwanted packets are mixed. Even if a packet between real-time communication terminals is identified by an IP address and transferred on a network different from general traffic, a non-real-time communication packet between real-time communication terminals gives a delay variation to the real-time communication packet. In this case, the router type uses the communication type, the source address, the destination address, the source port number, the destination port number, the packet length, and the identifier to identify the packet. In order to accurately identify the real-time communication packet from these attributes, it is necessary to identify a combination of multiple attributes. On the other hand, if the rules for identifying packets are complicated, the load on the router device may be reduced and the transfer capability may be reduced.

Therefore, an object of the present invention is to solve these conventional problems, identify a packet by a simple rule, prioritize transfer of a real-time communication packet, and prevent delay and delay fluctuation. An object of the present invention is to provide an apparatus, a scheduling method, a program thereof, and a recording medium.

[0008]

In order to achieve the above object, a packet scheduling device of the present invention comprises a dividing unit for dividing a packet into a designated length and a rate control unit for transferring a packet at a designated transfer rate. In the packet scheduling device, the packet between the real-time communication terminals is identified in advance by the routing processing, the packet division unit divides the packet exceeding the designated length into the designated length, and the divided packets are sent to the rate control unit. The packet is transferred and the packet which is not divided is transferred to the packet output unit and output from the packet output unit to the line, while the rate control unit transfers the packet to the packet output unit at the specified transfer rate.

Further, in the packet scheduling device of the present invention, the packet dividing unit divides the packet exceeding the designated length into the designated length, and transfers the divided packets to the non-priority queue of the packet queue group, A feature of the present invention is that undivided packets are transferred to the priority queue of the packet queue group, and the packet queue group preferentially transfers the packets of the priority queue to the packet output unit.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. (First Embodiment) FIG. 1 is a block diagram of a packet scheduling apparatus showing a first embodiment of the present invention. In the first embodiment, the non-real-time communication packet is divided into a predetermined length, and the transfer rate of the divided packet is suppressed so that the real-time communication packet is queued for a time period that affects the real-time communication quality. Without sending to the output line with little delay. Line 41 is
Unless the bandwidth is small and packet division and priority transfer processing is not performed, non-real-time communication packets between real-time communication terminals cause delay variations in the real-time communication packets, degrading communication quality.

Therefore, in this embodiment, in the routing process in the preceding stage of the packet scheduling device, I
It is assumed that packets between the real-time communication terminals are identified in advance based on conditions such as P address and they are input to the packet input unit 11 of the packet scheduling device. The packet input unit 11 transfers the packet to the packet dividing unit 12. The packet dividing unit 12 includes a packet input unit 11
Packets transferred from the above are divided into packets having a specified length, the packets 34 are transferred to the rate control unit 16, and the undivided packets 33 are transferred to the packet output unit 15. To do. The real-time communication packet has a short packet length, and the non-real-time communication packet has a long packet length. Therefore, a packet exceeding the specified length is a non-real-time communication packet. The rate control unit 16 transfers packets at the specified transfer rate. The rate control unit 16 transfers to the packet output unit 15 at the specified transfer rate. The packet output unit 15 transfers the packet to the line 41.

FIG. 4 is an operation flowchart of the packet scheduling apparatus showing the first embodiment of the present invention. In the routing processing unit in the preceding stage of the packet scheduling device, first, it is discriminated whether or not it is a packet between real-time communication terminals in advance by conditions such as an IP address,
If it is a packet between real-time communication terminals, it is transferred from the packet input unit 11 to the packet dividing unit 12. The packet dividing unit 12 determines whether or not the designated length is exceeded (step 101), and if the designated length is exceeded, the packet is divided into packets of the designated length (step 102). In addition,
Since the real-time communication packets are previously arranged into short packets, all the divided packets are non-real-time communication packets. Rate control unit 1 for the divided packets
On the other hand, the packet that is not divided is immediately transferred to the packet output unit 15 (step 105), and the packet that is not divided is transferred from the packet output unit 15 to the line 41 (step 106). The rate control unit 16 suppresses the transfer rate of the divided packets (step 103), and outputs the packets from the packet output unit 15 to the line 41 (step 104).

(Modification) Next, a modification of the first embodiment will be described. In FIG. 1, the packet division unit 12 has the function of the rate control unit 16, and controls the transmission rate of the packets divided by the packet division unit 12. That is, the packet dividing unit 12 divides the packet exceeding the specified length into the specified length, transfers only the non-divided packet 33 to the packet output unit 15, and, for the divided packet 34, the transmission rate. And transfers the packet to the packet output unit 15. As described above, according to this modification, the rate control unit 16 in FIG. 1 is deleted, so that the device is further simplified.

According to the first embodiment, the non-real-time communication packet between the real-time communication terminals is divided into a length that does not affect the real-time communication quality, and the real-time communication packet is awaiting transmission into a plurality of non-real-time communication packets. No delays.

(Second Embodiment) FIG. 2 is a block diagram of a packet scheduling apparatus showing a second embodiment of the present invention. In the second embodiment, the non-real-time communication packet is divided into designated lengths, the divided packets are transferred to the non-priority queue of the packet queue group, and the non-division packet that is the real-time communication packet is prioritized queue of the packet queue group. By transferring the real time communication packet, the real time communication packet is preferentially transferred. The line 41 has a small band, and unless packet division and priority transfer processing is performed, the non-real-time communication packet between the real-time communication terminals causes delay variation in the real-time communication packet and deteriorates communication quality.

In the routing process, which is the first stage of the packet scheduling device, the packets between the real-time communication terminals are identified in advance according to the conditions such as the IP address,
It is assumed that they are input to the packet input unit 11 of the packet scheduling device. Packet input unit 11
Transfers the packet to the packet dividing unit 12.

The packet dividing unit 12 includes a packet input unit 1
Among the packets transferred from 1, the packets exceeding the specified length are divided into specified lengths, the divided packets 34 are transferred to the non-priority queue 22 of the packet queue group 14, and the undivided packets are not divided. 33 is transferred to the priority queue 21 of the packet queue group 14. The packet queue group 14 transfers the packets of the priority queue 21 to the non-priority queue 2
The second packet is transferred to the packet output unit 15 with priority. The packet output unit 15 transfers the packet to the line 41.

FIG. 5 is an operation flowchart of the packet scheduling apparatus showing the second embodiment of the present invention. A routing processing unit in the preceding stage of the packet scheduling device identifies in advance whether it is a packet between real-time communication terminals based on conditions such as an IP address, and if so, it is input to the packet input unit 11 of the packet scheduling device. . The packet is a packet input unit 11
From the packet division unit 1 to the packet division unit 1
In 2, it is judged whether or not the designated length is exceeded (step 201), and if it is exceeded, the packet is divided into designated lengths (step 202).

The packet queue group 14 is provided for the divided packets.
To the priority queue 21 of the queue group 14 (step 206). Next, the packets in the priority queue 21 are sequentially transferred to the line 41 via the output unit 15 (step 207). If there is a packet to be transferred in the priority queue 21 (step 204), it is transferred sequentially (step 207). On the other hand, when there are no packets to be transferred to the priority queue 21, the packets in the non-priority queue 22 are transferred to the line 41 via the output unit 15 (step 205).

(Modification) Next, a modification of the second embodiment will be described. This is because the non-priority queue of the packet queue group is provided with the function of the packet dividing unit so that the divided packets are transferred to the packet output unit with non-priority. That is, the packet dividing unit 12 has a function of only judging whether or not there is a packet having a length equal to or more than the designated length and classifying the packet, and transfers the undivided packet 33 ′ to the priority queue 21 of the packet queue group 14. , The scheduled packet 34 ′ is transferred to the non-priority queue 22. In the non-priority queue 22, a packet having a length longer than or equal to the designated length is divided into designated lengths, and the packets are connected to the non-priority queue 22 again. After that, it is the same as the second embodiment.

According to the second embodiment, the non-real-time communication packet between the real-time communication terminals is divided into lengths that do not affect the real-time communication quality, and the real-time communication packet is awaiting transmission into a plurality of non-real-time communication packets. No delays.

The flow of the packet scheduling method shown in FIGS. 4 and 5 is converted into a program for causing a computer to execute, and the converted packet scheduling program is stored in a recording medium such as a CD-ROM. The present invention can be easily realized by mounting the upper recording medium on a computer that controls or sets a router device that transfers packets between real-time communication terminals, installs a program on the router device, and executes the program. .

[0023]

As described above, according to the present invention,
The non-real-time communication packet between the real-time communication terminals is divided into lengths that do not affect the real-time communication quality, and the transfer rate is suppressed or non-priority transfer is performed, so the real-time communication packet is sent to multiple non-real-time communication packets. No waiting delay. Further, it is possible to prevent the quality deterioration of the real-time communication due to the non-real-time communication packet between the real-time communication terminals without performing the packet priority transfer based on the information of the packet header which becomes the load of the router.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a packet scheduling device showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a packet scheduling device showing a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional packet scheduling device.

FIG. 4 is an operation flowchart of the packet scheduling apparatus showing the first embodiment of the present invention.

FIG. 5 is an operation flowchart of a packet scheduling device showing a second embodiment of the present invention.

[Explanation of symbols]

11 ... Packet input unit, 12 ... Packet division unit, 14 ...
Packet queue group, 15 ... Packet output unit, 33 ... Non-divided packet, 34 ... Divided packet, 16 ... Rate control unit, 21 ... Priority queue, 22 ... Non-priority queue, 41 ... Line, 31 ... Real-time communication packet, 32 ... Non-real-time communication packet.

Claims (8)

[Claims] 1. A packet scheduling device incorporated in a router device, wherein a packet input unit to which a packet is input after it is identified as a packet between real-time communication terminals by a condition such as an IP address in routing processing. A packet dividing unit that divides a packet that exceeds the specified length among the packets transferred from the packet input unit into a specified length, and when the divided packets are transferred, at the specified transfer rate A rate control unit for transferring the packet, an undivided packet transferred from the packet dividing unit,
And a packet output unit which outputs the packet to a line when the divided packet transferred from the rate control unit is received. 2. The packet scheduling device according to claim 1, wherein the packet division unit has a function of a rate control unit, and controls the transmission rate of the packets divided by the packet division unit. Scheduling device. 3. A packet scheduling device incorporated in a router device, wherein a packet input unit to which the packet is input after it is identified as a packet between real-time communication terminals by a condition such as an IP address in the routing process. Among the packets transferred from the packet input unit, a packet dividing unit that divides a packet exceeding a specified length into a specified length, a divided packet into a non-priority queue, and a packet that is not divided into A packet queue group connected to the priority queue, and a packet output unit for outputting the packet of the priority queue of the packet queue group with priority over the packet of the non-priority queue and outputting the packet to the line. Packet scheduling device. 4. The packet scheduling device according to claim 3, wherein the non-priority queue of the packet queue group has a function of a packet dividing unit, and the packet divided by the non-priority queue is transferred to the packet output unit with non-priority. A packet scheduling device characterized by the above. 5. A packet scheduling method in a router device, wherein among packets identified as packets between real-time communication terminals by routing processing, packets exceeding a specified length are divided into specified lengths, Characterized by directly transferring the divided packets to a rate control unit that transfers the packets at a specified rate, directly transferring the undivided packets to the packet output unit, and transferring the transferred packets from the packet output unit to the line Packet scheduling method. 6. A packet scheduling method in a router device, wherein among packets identified as packets between real-time communication terminals by routing processing, packets exceeding a specified length are divided into specified lengths, The divided packets are transferred to the non-priority queue of the packet queue group, the non-divided packets are transferred to the priority queue of the packet queue group, and the packets of the priority queue of the packet queue group are output with priority over the non-priority queue. And a transferred packet is transferred from the packet output unit to the line. 7. A packet scheduling program for causing a router device to execute the packet scheduling method according to claim 5 or 6. 8. A computer-readable recording medium on which the packet scheduling program according to claim 7 is recorded.