JP2004363841A - Packet transmitting device, packet receiving device, packet transfer device, and packet transmitting/receiving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To distribute stream data of a moving picture, audio, etc., without any break while guaranteeing service quality by performing priority control over the stream data at application level. <P>SOLUTION: A packet transmitting device sets a high-layer protocol identifier indicating high-layer protocol and sequence numbers for sequencing a series of transmit packet in header fields of the transmit packets, a packet transfer device performs priority transfer processing according to the high-layer protocol identifier or sequence numbers set in the packets to be transferred, and a packet receiving device determines a reception processing method from the high-layer protocol identifier set in the packets and performs assembling and reproducing processing for the data according to the sequence numbers when received packets contain stream data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an information device for connecting from an information device connected to a network such as a home to another network such as the Internet, and to a network system including the information device and a gateway device.
[0002]
[Prior art]
In recent years, in the field of communication, the Internet Protocol (IP), which is a standard protocol of the Internet, has become the de facto standard protocol, and the IP protocol has been used even in homes. In such a situation, it is becoming more common to connect from an in-home network to an out-of-home network, perform e-mail with information equipment connected to the out-of-home network, and obtain information from the out-of-home network. The information from the network outside the home often transmits and receives not only a still image but also data (stream data) having real-time characteristics such as a moving image and a voice. When transmitting and receiving such stream data, RTP (Realtime Transport Protocol) or the like is used as a standard protocol (see Non-Patent Document 1).
[0003]
In addition, there is a technology in which moving images and sounds are reproduced without interruption at a receiving destination by transferring the stream data at a high priority. As an example of a technique for transferring the data at a high priority, in order to prevent retransmission of unnecessary data, when the end system returns an acknowledgment (ACK), the ToS (Type) in the IP packet storing the ACK is used. of Service) field (or a label field of IPv6) is set to a predetermined value indicating high-priority transfer, so that the packet storing the ACK is transmitted to the end system in the same direction. There is a technique for transmitting data preferentially compared to packets (see Patent Document 1).
[0004]
Further, as an example of a method of using the IPv6 label field, there is a method of using a flow label. The use of the flow label is currently under study, but at present, it is assumed that the same source address, destination address, and flow label are assigned to all packets belonging to the same flow (Non-Patent Document 2). reference).
[0005]
[Patent Document 1]
JP 2001-127830 A [Non-Patent Document 1]
Streaming System (I) Protocol and Authoring Internet Week 2001 Tutorial Lecture Materials P26
http: // www. soi. wide. ad. jp / iw2001 / slides / 06 / 06-2 / 26. html
[Non-patent document 2]
Appendix A. Semantics and Usage of the Flow Label Field
Internet Protocol Version 6 (IPv6) Specification RFC2460 P30
http: // www. arin. net / library / rfc / rfc2460. txt
[0006]
[Problems to be solved by the invention]
The transmission and reception of stream data is performed using the RTP protocol. In the RTP protocol, on the receiving side, processing for synchronizing reproduction, detecting packet loss, and discarding packets with a large delay is performed based on the time stamp and sequence number. Since this RTP protocol is implemented on UDP (User Datagram Protocol), it is difficult to guarantee quality of service (QoS: Quality of Service). Therefore, there is a problem that packet loss or delay may occur on the route, so that the moving image or the voice is interrupted. Also, in order to guarantee such QoS, it is necessary to realize it at the application level, which is very troublesome.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, in a network system having a packet transmitting device that transmits a packet, a packet receiving device that receives the packet, and a packet transmitting device that transfers the packet between networks,
The packet transmitting device sets an upper layer protocol identifier indicating an upper layer protocol and a sequence number for ordering a series of transmission packets in a header field of the transmission packet. More specifically, the network system is an IPv6 network, and sets an upper layer protocol identifier and a sequence number in a flow label of an IPv6 header field. The output interface secures the communication band of the transmission packet according to the upper layer identifier and transmits the packet.
[0008]
Further, the packet transfer device transfers the packet preferentially according to the upper layer protocol identifier or the sequence number set for the packet to be transferred.
Further, the packet receiving apparatus determines a receiving processing method based on an upper layer protocol identifier set in the packet, and when the received packet is stream data, performs data assembling and reproducing processing according to the sequence number.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing an example of the system configuration of the present invention. 1 is a network outside the home, for example, the Internet, 2 is a home network, for example, a home network, 3 is a device connected to the Internet, for example, a packet transmission device in the present invention, and 4 is a device connected to the home network 2, for example, a book. The packet receiving device 5 in the invention is a packet transfer device, for example, a gateway device. Reference numerals 51 and 52 denote packet transfer devices existing on the Internet 1, for example, edge routers. An object of the present invention is to provide a method in which a packet receiving apparatus 4 connected to a home network 2 can receive stream data from a packet transmitting apparatus 3 connected to the Internet 1 without interruption in the system configuration shown in FIG. It is to provide.
[0010]
The packet transmitting device 3 of the present invention will be described in detail. FIG. 2 is a diagram illustrating a configuration of the packet transmission device 3. 6 is a header field generating means, 6a is an upper layer protocol setting means for identifying an upper layer protocol and setting an identifier for each upper layer protocol, 6b is incrementing (decrementing) from an arbitrarily set identifier, and A sequence number setting means for performing ordering; 6c, an identifier setting means for setting the identifier set by the upper layer protocol setting means 6a and the sequence number set by the sequence number setting means 6b in the header field of the transmission packet; A packet assembling means for generating a transmission packet reflecting the header field generated by the generating means 6, a packet transmitting means 8 for transmitting the packet generated by the packet assembling means, and a packet receiving means 9, which will be described later, including a receiving process. Reference numeral 10 shown in FIG. 3 is an example of an identifier table held by the upper layer protocol setting unit 6a, and the correspondence between the upper layer protocol 10a and the identifier 10b is established. When transmitting stream data from the packet transmitting device 3, the upper layer protocol setting means 6a determines which upper layer protocol 10a is used.
[0011]
In the embodiment of the present invention, for example, if the upper layer protocol 10a is RTP (Realtime Transport Protocol), the identifier 10b is "0001" as shown in FIG. This identifier 10b is set in the header field of the transmission packet. FIG. 4 shows a part of a packet to be transmitted. Reference numeral 11 denotes a packet group for transmitting a series of stream data, for example, ABC, and reference numeral 11a denotes an example of a sequence number set by the sequence number setting means 6b. 11b shows stream data. For example, when a packet for transmitting data A in a series of stream data is generated, the identifier 10b for the upper layer protocol 10a is "0001", and the sequence number 11a set by the sequence number setting means 6b is "01". .
[0012]
Here, the sequence number 11a is an arbitrary value, but is set to “01” in the present embodiment for simplification of the description. Further, the sequence number 11a may be set in the transmission packet generation order. Further, as the sequence number 11a, a sequence number included in the upper layer protocol 10a may be used as it is, or a part of the sequence number, for example, lower n bits may be set. Next, when a packet for transmitting data B is generated, the identifier 10b for the upper layer protocol 10a becomes "0001" like the data A, and the sequence number 11a set by the sequence number setting means 6b is incremented to the sequence number of the data A. "02". The data C is similarly set, and is reflected in the header fields of the transmission packets 111 to 113 by the identifier setting means 6c. The packet assembling means 7 generates a transmission packet reflecting the upper layer protocol identifier 10b and the sequence number 11a set in the header field by the header field generating means 6, and entrusts the transmission to the packet transmitting means.
[0013]
Next, the operation of the packet transfer device 5 will be described. FIG. 5 is a diagram showing the packet transfer device 5 in detail. 12 is a transfer path determining means for determining a transfer path of a received packet, 13 is a transfer order determining means for determining a transfer priority according to an upper layer protocol identifier 10b set in a header field of a packet to be transferred, and 14 is a transfer processing. The management unit holds the transfer order table 15 referred to by the transfer order determination unit. Reference numeral 16 denotes a packet transfer unit that transfers a packet according to the priority determined by the transfer order determination unit 13.
[0014]
The packet transmitted from the packet transmission device 3 to the packet reception device 4 is subjected to a transfer process by the packet transfer device 5. The route of the packet received by the packet transfer device 5 to the packet reception device 4 is determined by the transfer route determination unit 12. Next, the transfer order determination unit 13 determines the transfer order of the packet with reference to the transfer order table 15 held by the transfer processing management unit 14. For example, when the upper layer protocol identifier 10b is "0001", the transfer processing order is "1" from the transfer order table 15, so that the packet transfer means 16 performs the transfer processing with priority over other packets. At this time, a special identifier may be added to the traffic class area (priority designation area) of the IPv6 header field in order to simplify the processing of another packet transfer apparatus existing on the path to the packet receiving apparatus 4.
[0015]
Further, the packet transfer device 5 has a feature of transferring packets in the order of the sequence number 11a set in the transfer packet. FIG. 6 is a diagram showing the sequence number processing. 17 is a sequence number processing means, and 18 is a transfer processing queue. The number is a sequence number set in the packet by the packet transmitting device 3. For example, assume that the packet transfer device 5 receives packets in the order of sequence numbers 1, 2, 4, 3, and 5. In this case, since the packet of sequence number 4 and the packet of sequence number 3 are interchanged, the sequence number processing means 17 performs the transfer processing of the packets of sequence numbers 1 and 2 as they are, and the packet of sequence number 4 To wait.
[0016]
When the transfer processing of the packet of sequence number 3 is completed, the packet of sequence number 4 waiting in the transfer processing queue 18 is released and the transfer processing is performed. This allows early detection of packet loss and delay. That is, in the upper layer protocol 10a for transmitting and receiving stream data, such as the conventional RTP, the packet arrives at the packet receiving device 4 and the loss or delay of the packet is found at the time of assembling and reproducing the data. This can be clarified by the packet transfer device 5 installed on the route to the device 4. As a result, it is also possible to take measures such as early detection of packet loss and delay, and requesting retransmission of the packet.
[0017]
Further, the packet transfer device 5 has a function of securing a communication band according to the upper layer protocol identifier 10b set for a packet to be transferred. For example, a packet to be transferred with a high priority from the upper layer protocol identifier 10b secures a wide band, and does not secure a band of a packet that is not so important for transfer such as FTP.
[0018]
As described above, the packet transfer apparatus 5 according to the present invention preferentially transfers a packet or secures a communication band according to the upper layer protocol identifier 10b set in the header field of the transfer packet or the set sequence number 11a. Perform processing.
[0019]
Next, a processing procedure of the packet receiving device 4 according to the present embodiment will be described. FIG. 7 is a diagram showing the packet receiving device 4 in detail. 19 is an identifier discriminating unit, and 20 is a data reproducing unit. The packet received by the packet receiving means 9 is discriminated by the identifier discriminating means 19 by referring to the identifier table 10 from the upper layer protocol identifier 10b set in the header field of the received packet. Next, the upper layer protocol 10a determined by the identifier determining means 19 determines whether or not the data is stream data. If it is not stream data, the process is left to the upper layer. When it is determined that the data is stream data, the data reproducing unit 20 cuts out the sequence number 11a set in the header field and the stream data from the received packet, and assembles and reproduces the data in the sequence number 11a order. The packet transmission means 8 and the packet transmission processing are described in detail in the embodiment of the packet transmission device.
[0020]
According to the embodiment of the present invention described above, the stream data transmitted from the packet transmission device 3 can reach the packet reception device 4 reliably and with high priority.
[0021]
Next, an embodiment of the packet transmission device 3 according to the present invention will be described in more detail by taking an IPv6 network as an example. FIG. 8 is a diagram showing a header field of an IPv6 packet. 21 indicates a flow label area of the IPv6 header field. A feature of the present invention is that the upper layer protocol identifier 10b and the sequence number 11a are set in the flow label area 21 of the IPv6 header field. In the figure, reference numeral 21a denotes upper bits of the flow label area 21 and an upper layer protocol identifier 10b, and reference numeral 21b denotes lower bits of the flow label area 12 and indicates a sequence number 11a. The method of setting the IPv6 header field in the flow label area 21 by the upper layer protocol identifier 10b and the sequence number 11a is the same as the method of setting the header field of the packet described above.
[0022]
Upon receiving the IPv6 packet, the packet transfer device 5 determines the upper layer protocol 10a of the transfer packet from the upper bits 21a of the flow label area 21, and performs priority transfer processing of the packet according to the protocol. The packet transfer device 5 performs a packet transfer process in the order of the sequence numbers 11a set in the lower bits 21b of the flow label area 21. Further, the packet transfer device 5 secures a communication band according to the upper layer protocol identifier 10b set in the upper bit 21a of the flow label area 21. Next, the packet receiving device 4 determines the upper layer protocol 10a from the upper layer protocol identifier 10b, and if this is stream data, assembles or reproduces the data according to the sequence number 11a set simultaneously by the packet transmitting device 3. .
[0023]
The above is the embodiment of the present invention in the IPv6 network. When setting the flow label area 21 in the IPv6 header field, the upper bit 21a is set to the upper layer protocol identifier 10b, and the lower bit 21b is set to the sequence number 11a. However, the upper layer protocol identifier 10b and the sequence number 11a may be set in reverse. Also, no matter how the upper layer protocol identifier 10b and the sequence number 11a are set in the flow label area 21 of the IPv6 header field, there is no particular problem as long as the packet transfer device 5 and the packet reception device 4 can be identified.
[0024]
As described above, according to the present invention, by providing an identifier for identifying the upper layer protocol and a sequence number in the header field of the packet, it is not necessary to use a special protocol such as RTP of the upper layer protocol. However, there is no problem if both the present invention and the upper layer protocol are incorporated in the packet. In addition, according to the present invention, the QoS guarantee, which has been conventionally realized at the application level, is automatically set, and at the same time, the packet is transferred by the packet transfer device in sequence number order. Is reachable.
[0025]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, when transmitting and receiving the stream data of a moving image, audio | voice, etc., it becomes possible to communicate without using a special upper layer protocol such as RTP. Also, priority control can be performed by the identifier and sequence number of the upper layer protocol provided in the header field of the packet.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram using an apparatus according to an embodiment of the present invention.
FIG. 2 is a configuration diagram of a packet transmission device.
FIG. 3 is a diagram illustrating an identifier table included in the packet transmission device.
FIG. 4 is a diagram illustrating a part of a packet transmitted from the packet transmission device.
FIG. 5 is a configuration diagram of a packet transfer device.
FIG. 6 is a diagram showing a sequence number processing means provided in the packet transfer device.
FIG. 7 is a configuration diagram of a packet receiving device.
FIG. 8 is a diagram showing a header field of an IPv6 packet.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Internet 2 ... Home network 3 ... Packet transmitting device 4 ... Packet receiving device 5 ... Packet transfer device 6 ... Header field generating means 6a ... Upper layer protocol setting means 6b ... Sequence number setting means 6c ... Identifier setting means 7 ... Packet assembly Means 8 Packet transmitting means 9 Packet receiving means 10 Identifier table 11 A series of stream data 11a Sequence number 11b Stream data to be transmitted 12 Transfer path determining means 13 Transfer order determining means 14 Transfer processing managing means 15 ... Transfer order table 16 ... Packet transfer means 17 ... Sequence number processing means 18 ... Transfer processing queue 19 ... Identifier determination means 20 ... Data reproduction means 21 ... Flow label area of IPv6 header field

Claims (11)

A packet transmission device for transmitting a packet, a packet reception device for receiving the packet, and a packet transmission device used for a network system having a packet transmission device for transmitting the packet between networks,
A header generating means for generating a header field of the transmission packet, a packet assembling means for assembling the transmission packet, and a packet transmitting means for transmitting the packet generated by the packet assembling means;
The header generating means includes an upper layer protocol setting means for generating an identifier for identifying an upper layer protocol, a sequence number setting means for ordering a series of transmission packets, and an identifier setting means. A packet transmission device, wherein a layer protocol identifier and a sequence number are set in a header field of a transmission packet. 2. The packet transmitting apparatus according to claim 1, wherein the sequence number setting unit generates the packet by incrementing or decrementing it from an arbitrary value in the order of generation of the packet. 2. The packet transmitting apparatus according to claim 1, wherein the sequence number setting unit generates the sequence number using a sequence number managed or used by an upper layer protocol. 2. The packet transmitting apparatus according to claim 1, wherein the sequence number setting unit generates the sequence number using a part of a sequence number managed or used by an upper layer protocol. The transmission packet is an IPv6 (Internet Protocol Version 6) packet, and the upper layer protocol identifier and a sequence number are set in a flow label area of the IPv6 header field. A packet transmitting device according to any one of the above. A packet transmission device for transmitting a packet, a packet reception device for receiving the packet, and a packet transfer device used in a network system having a packet transfer device for transferring the packet between networks,
A protocol management unit that manages an upper layer protocol identifier set in a header field of a packet to be transferred; the protocol management unit holds a protocol management table that associates an upper layer protocol identifier with a transfer order; A packet transfer device for performing a packet transfer process according to a protocol management table. The apparatus further comprises a sequence number management means for managing a sequence number for ordering the packets set in the header field of the packet to be transferred, wherein the sequence number management means transfers the packets in the order of the sequence numbers. The packet transfer device according to claim 6. 8. The communication device according to claim 6, further comprising a QoS control unit for realizing service quality, wherein a communication band is secured on a path from the packet transmission device to the packet reception device according to an upper layer protocol identifier. A packet transfer device according to claim 1. A packet transmitting device for transmitting a packet, a packet receiving device for receiving the packet, and a packet receiving device used in a network system having a packet transfer device for transferring the packet between networks,
A packet receiving apparatus for assembling and reproducing data from an upper layer protocol identifier for identifying an upper layer protocol set in a header field of a received packet and a sequence number for ordering packets. A packet transmitting and receiving apparatus for transmitting and receiving packets, and a packet transmitting and receiving apparatus used in a network system having a packet transfer apparatus for transferring the packet between networks,
An upper layer protocol identifier for identifying an upper layer protocol by a header generation means for generating a header field of a transmission packet, and a transmission means for transmitting a packet by setting a sequence number for ordering a series of transmission packets in the header field,
A packet transmitting / receiving apparatus comprising: receiving means for assembling and reproducing data from an upper layer protocol identifier set in a header field of a received packet and a sequence number for ordering packets, and performing a bidirectional stream. . When the packet receiving means receives a packet, when transmitting a packet confirming packet arrival or confirming packet non-arrival, an upper layer protocol identifier for identifying an upper layer protocol and a sequence number for ordering the packet are provided in a header. The packet transmission / reception apparatus according to claim 10, wherein the packet transmission / reception priority processing is performed by setting a field and transmitting the packet.

Images