JP4600251B2 - Packet discrimination device and packet discrimination method - Google Patents

Description

  The present invention relates to a packet discrimination device and a packet discrimination method. In particular, the present invention relates to an RTP (Real-time Transport Protocol) discrimination device and discrimination method.

As an example of conventional system priority control for VoIP (Voice over IP (Internet Protocol)), the session state is monitored, and based on the information of the flow control monitoring unit in the central control computer device, the flow control unit is at the application level. With this packet processing, priority control is performed on packets used for voice calls. At this time, the packet selection in the priority control is selected based on the application session information and the like.
JP 2003-46563 A

  However, packet selection in prior art priority control requires monitoring of the session state and further using application session layer application session information, etc., and thus a device with generally high specifications is required. And has the disadvantage of high cost.

  In order to solve such a problem, a packet discrimination device according to the present invention is a packet discrimination device that discriminates the type of a packet in the layer 2 of the packet, assuming that the input packet is a packet including an audio signal. A first acquisition unit that acquires link header information, a second acquisition unit that acquires network header information of the packet, a third acquisition unit that acquires transport header information of the packet, and an arbitrary bit of the packet A fourth acquisition unit for acquiring information, and the packet is an RTP packet based on the information acquired by the first acquisition unit, the second acquisition unit, the third acquisition unit, and the fourth acquisition unit. And a packet discriminating unit for discriminating whether or not.

  In order to solve such a problem, a packet discrimination method according to the present invention is a packet discrimination method for discriminating the type of a packet in the layer 2 of the packet, assuming that the input packet includes a voice signal. A first acquisition step of acquiring data link header information of the packet, a second acquisition step of acquiring network header information of the packet, a third acquisition step of acquiring transport header information of the packet, and an arbitrary packet A fourth acquisition step of acquiring bit information, and based on the information acquired in the first acquisition step, the second acquisition step, the third acquisition step, and the fourth acquisition step, A parameter for determining whether the packet is an RTP (Real-time Transport Protocol) packet. And a ticket discriminating step.

  According to the packet discriminating apparatus / packet discriminating method of the present invention, the function of reading the data link header of the packet, the function of reading the network header, the function of reading the transport header, and the function of acquiring an arbitrary bit in the packet are provided. By providing, it is possible to determine with high accuracy that one packet is an RTP packet.

  A first embodiment of the present invention will be described with reference to the drawings.

(A) First Embodiment (A-1) Configuration of First Embodiment FIG. 1 is a block diagram showing a packet discrimination configuration of a network device according to the first embodiment of the present invention.

  The configuration of the packet discriminating apparatus (RTP packet discriminating apparatus 1) includes a packet acquiring unit 11 that acquires an input packet, a data link header that acquires header information of a data link layer in the packet, Network header information acquisition unit 13 that acquires network layer header information, transport header information acquisition unit 14 that acquires transport layer header information in a packet, and bit information acquisition unit 15 that acquires arbitrary bit information in a packet And whether the packet type is RTP based on the information obtained by the data link header acquisition unit 12, network header information acquisition unit 13, transport header information acquisition unit 14, and bit information acquisition unit 15. A packet to determine whether it is from another packet Having a determination section 16. Further, the packet type result determined by the RTP packet determination device 1 is transmitted to a packet processing unit [not shown], and the packet processing unit [not shown] responds to the determined packet type result. Then, priority control of the acquired packet is performed. Details of each component will be described below.

  Assuming that the acquired packet is a VoIP packet, the data link header acquisition unit [FIG. 1:12] extracts data at a location corresponding to the destination MAC address header of the data link header information (MAC header), and the packet The determination unit [FIG. 1: 16] determines whether the extracted data is a multicast address or a broadcast address in the destination MAC address header in the MAC address of the acquired packet.

  Assuming that the acquired packet is a VoIP packet, the network header acquisition unit [FIG. 1: 13] extracts data at a location corresponding to the protocol of the network header information (IP header), and the packet determination unit [FIG. : 16] determines whether the extracted data is UDP in the data format of the acquired packet.

  Assuming that the acquired packet is a VoIP packet, the transport header acquisition unit [FIG. 1:14] extracts data corresponding to the destination port of the UDP header of the transport header information (UDP header), The packet discriminating unit [FIG. 1: 16] discriminates whether the extracted data is a port number (even number of 1026 or more) used in RTP at the destination port of the UDP header of the transport header information (UDP header) of the acquired packet. To do.

  The transport header acquisition unit [FIG. 1:14] assumes that the acquired packet is a VoIP packet, extracts data corresponding to the UDP data length of the transport header information (UDP header), and determines the packet. The unit [FIG. 1: 16] determines whether the extracted data is equal to or larger than the minimum RTP size in the UDP data length of the transport header information (UDP header) of the acquired packet.

  Assuming that the acquired packet is a VoIP packet, the bit information acquisition unit [FIG. 1:15] extracts data at a location corresponding to the version of the RTP header in the transport data (UDP payload) to determine the packet. The part [FIG. 1: 16] determines whether the extracted data is the version currently used in the version of the RTP header in the transport data (UDP payload) of the acquired packet.

  Assuming that the acquired packet is a VoIP packet, the bit information acquisition unit [FIG. 1:15] extracts data at a location corresponding to the most significant bit of the payload type in the transport data (UDP payload), The packet discriminating unit [FIG. 1: 16] has an RTP payload type in the transport data (UDP payload) of the packet acquired by the extracted data, and the media type includes voice [0 in the most significant bit of the payload type]. Determine if it exists.

  The bit information acquisition unit [FIG. 1:15] assumes that the acquired packet is a VoIP packet, extracts data corresponding to padding in the transport data (UDP payload), and extracts the packet discrimination unit [FIG. 1:16] determines whether there is no padding in the information regarding the padding in the transport data (UDP payload) of the packet acquired by the extracted data.

When the packet discriminating unit [FIG. 1: 16] discriminates that the acquired packet is not an RTP packet, the packet processing unit [not shown] performs processing related to the packet in a procedure other than the RTP packet. . Here, when the packet discriminating unit [FIG. 1: 16] discriminates that the acquired packet is not an RTP packet, it includes a case where any of the following <condition: a> to <condition: g> is included.
<Condition: a>
The destination MAC address header in the MAC address of the packet obtained by the extracted data is a multicast address or a broadcast address.
<Condition: b>
The data format of the packet acquired by the extracted data is not UDP.
<Condition: c>
The destination port of the UDP header of the transport header information (UDP header) of the packet obtained by the extracted data is not the port number (even number of 1026 or more) used in RTP.
<Condition: d>
The UDP data length of the transport header information (UDP header) of the packet obtained by the extracted data is not more than the minimum size of RTP.
<Condition: e>
The version of the RTP header in the transport data (UDP payload) of the packet obtained by the extracted data is not the currently used version.
<Condition: f>
The RTP payload type in the transport data (UDP payload) of the packet acquired by the extracted data is not the media type including voice [0 in the most significant bit of the payload type].
<Condition: g>
The packet transport data (UDP payload) obtained by the extracted data has no padding.

  When the packet discriminating unit [FIG. 1:16] discriminates that the acquired packet is an RTP packet (when none of the above <condition: a> to <condition: g> is included), the bit information acquisition unit [FIG. 1:15] assumes that the acquired packet is a VoIP packet, extracts data at a location corresponding to the information related to the extension header of the RTP header in the transport data (UDP payload), and determines the packet discrimination unit. [FIG. 1:16] determines whether or not there is an extension header in the information related to the extension header of the RTP header of the packet obtained by the extracted data.

  When the packet discriminating unit [FIG. 1: 16] determines that the acquired packet has an extension header in the RTP header in the transport data (UDP payload), the “UDP” in the transport data (UDP payload) of the acquired packet It is assumed that the value of “data size” − “16 bytes” is the size of the RTP payload.

  When the packet discriminating unit [FIG. 1: 16] determines that the acquired packet does not have an extension header in the RTP header in the transport data (UDP payload), the packet discriminating unit [UDP payload) in the acquired packet It is assumed that the value of “UDP data size” − “12 bytes” is the size of the RTP payload.

  Assuming that the acquired packet is a VoIP packet, the bit information acquisition unit [FIG. 1:15] extracts data at a location corresponding to the RTP payload in the transport data (UDP payload), and the packet determination unit [ FIG. 1:16] shows that in the RTP payload data in the transport data (UDP payload) of the packet obtained by the extracted data, the VoIP packet codec is G. 711 is determined.

  Assuming that the acquired packet is a VoIP packet, the bit information acquisition unit [FIG. 1:15] extracts data at a location corresponding to the RTP payload in the transport data (UDP payload), and the packet determination unit [ FIG. 1:16] shows that in the RTP payload data in the transport data (UDP payload) of the packet obtained by the extracted data, the VoIP packet codec is G. 729 is determined.

  The packet discriminating unit [FIG. 1: 16] is a G.D. protocol in which the acquired packet is RTP and the codec of the acquired packet is established by ITU-T. 711 and when the payload length is determined to be a multiple of 8 bytes, the packet processing unit [not shown] performs processing related to the acquired packet in codec: ITU-T. 711, Payload length: Performs priority control processing corresponding to RTP of multiple bytes of 8.

  The packet discriminating unit [FIG. 1: 16] is a G.D. protocol in which the acquired packet is RTP and the codec of the acquired packet is established by ITU-T. 729 and when the payload length is determined to be a multiple of 10 bytes, the packet processing unit [not shown] performs processing related to the acquired packet in codec: ITU-T. 729, Payload length: Priority control processing corresponding to RTP of multiple bytes of 10 is performed.

  When the packet discriminating unit [FIG. 1: 16] discriminates that the acquired packet is RTP and other RTP other than the above, the packet processing unit [not shown] performs processing related to the acquired packet. Processing of priority control corresponding to other RTP other than the above is performed.

(A-2) Operation of First Embodiment The operation of the first embodiment will be described with reference to FIGS. FIG. 2 is a flowchart showing the packet discrimination operation in the network device according to the first embodiment of the present invention. FIG. 3 shows the structure of layer 2 when the packet is VoIP in the first embodiment of the present invention. FIG. 4 shows the structure of the MAC header (Ethernet (registered trademark) V2 format) when the packet is VoIP in the first embodiment of the present invention. FIG. 5 shows the structure of the IP header when the packet is VoIP in the first embodiment of the present invention. FIG. 6 shows the structure of the UDP header when the packet is VoIP in the first embodiment of the present invention. FIG. 7 shows the structure of the RTP header in UDP data when the packet is VoIP in the first embodiment of the present invention. The present invention shows an operation of packet discrimination based on the data structure in layer 2 of the acquired packet. In Step 1 to Step 8, it is determined whether or not it is RTP from the layer 2 data structure of the acquired packet. Further, in step 9 to step 16, it is determined from the layer 2 data structure of the acquired packet whether the RTP is related to voice or other RTP, and the RTP related to voice is codec: ITU-T. Established G. 711, payload length: RTP that is a multiple of 8 bytes, or codec: G.E. 729 and payload length: RTP that is a multiple of 10 bytes.

<Step 1 [FIG. 2: S1]>
Step 1 [FIG. 2: S1] assumes that the acquired packet is a VoIP packet, extracts data corresponding to the destination MAC address header of the data link header information (MAC header), and the extracted data is It is determined whether the destination MAC address header in the MAC address of the acquired packet is not a multicast address or a broadcast address. Step 1 [FIG. 2: S1] is processed by the data link header acquisition unit [FIG. 1:12] and the packet discrimination unit [FIG. 1:16].

  An example of a specific determination process in step 1 [FIG. 2: S1] is as follows. The data link header acquisition unit [FIG. 1:12] obtains 1 from the beginning of the layer 2 structure 1 to 14 (bytes) [FIG. 3:32] in the layer 2 structure [FIG. 3:31] of the acquired packet. Data of ˜6 (bytes) [FIG. 4: 41] is extracted. The packet discriminating unit [FIG. 1: 16] discriminates whether the extracted data does not correspond to the multicast address or the broadcast address in the MAC address of the acquired packet. When the packet discrimination unit [FIG. 1:16] does not correspond to the multicast address or the broadcast address in the MAC address of the packet acquired in the discrimination result, the process of step 1 [FIG. 2: S1] is performed in step 2 [FIG. 2: When the process proceeds to the process of S2] and the MAC address of the packet acquired in the determination result corresponds to the multicast address or the broadcast address, the process of Step 1 [FIG. 2: S1] is performed in Step 8 [FIG. 2: S8]. Transition to processing.

<Step 2 [FIG. 2: S2]>
Subsequently, in step 2 [FIG. 2: S2], assuming that the acquired packet is a VoIP packet, the data corresponding to the protocol of the network header information (IP header) is extracted, and the extracted data is acquired. It is determined whether the data format of the packet is UDP. Step 2 [FIG. 2: S2] is processed by the network header acquisition unit [FIG. 1:13] and the packet discrimination unit [FIG. 1:16].

  An example of specific determination processing in step 2 [FIG. 2: S2] is as follows. The network header acquisition unit [FIG. 1: 13] obtains 10 (bytes) from the beginning of the layer 2 structure 15 to 34 (bytes) [FIG. 3: 33] in layer 2 [FIG. 3: 31] of the acquired packet. Data [FIG. 5: 51] is extracted. The packet discriminating unit [FIG. 1: 16] discriminates whether or not the extracted data corresponds to UDP (: the value of the extracted data is 17). When the data format of the packet acquired in the discrimination result corresponds to UDP (: value is 17), the packet discrimination unit [FIG. 1:16] performs step 2 [FIG. 2: S2] in step 3 [FIG. 2: When the process proceeds to S3] and the data format of the packet acquired in the determination result does not correspond to UDP (: value is 17), the process in Step 2 [FIG. 2: S2] is performed in Step 8 [FIG. 2: S8]. Transition to processing.

<Step 3 [FIG. 2: S3]>
Step 3 [FIG. 2: S3] assumes that the acquired packet is a VoIP packet, extracts data corresponding to the destination port of the UDP header of the transport header information (UDP header), and extracts the extracted data. Is the port number used in RTP in the destination port of the UDP header of the acquired packet. Step 3 [FIG. 2: S3] is processed by the transport header acquisition unit [FIG. 1:14] and the packet discrimination unit [FIG. 1:16].

  An example of specific determination processing in step 3 [FIG. 2: S3] is as follows. The transport header information acquisition unit [FIG. 1:14] starts from the top of the layer 2 structure 35 to 42 (bytes) [FIG. 3:34] in layer 2 [FIG. 3:31] of the acquired packet. Data of 4 (bytes) [FIG. 6: 61] is extracted. The packet determination unit [FIG. 1: 16] determines whether the extracted data corresponds to an even number of 1026 or more in the destination port of the UDP header of the acquired packet. When the destination port of the UDP header of the packet acquired in the discrimination result corresponds to an even number equal to or greater than 1026, the packet discriminating unit [FIG. 1: 16] performs step 3 [FIG. 2: S3] in step 4 [FIG. 2: If the process proceeds to S4] and the destination port of the UDP header of the packet acquired in the determination result does not correspond to an even number equal to or greater than 1026, the process in Step 3 [FIG. 2: S3] is performed in Step 8 [FIG. 2: S8]. Transition to processing.

<Step 4 [FIG. 2: S4]>
In step 4 [FIG. 2: S4], assuming that the acquired packet is a VoIP packet, the data corresponding to the UDP data length of the transport header information (UDP header) is extracted, and the extracted data is acquired. It is determined whether the UDP payload size is equal to or larger than the minimum RTP size in the UDP data length of the received packet. Step 4 [FIG. 2: S4] is processed by the transport header acquisition unit [FIG. 1:14] and the packet discrimination unit [FIG. 1:16].

  An example of specific determination processing in step 4 [FIG. 2: S4] is as follows. The transport header information acquisition unit [FIG. 1:14] starts from the beginning of the layer 2 structure 35 to 42 (bytes) [FIG. 3:34] in layer 2 [FIG. 3:31] of the acquired packet. Data of 6 (bytes) [FIG. 6: 62] is extracted. The packet discriminating unit [FIG. 1: 16] discriminates whether the extracted data corresponds to 20 bytes or more in the UDP data length of the acquired packet. When the packet discrimination unit [FIG. 1: 16] corresponds to 20 bytes or more in the UDP data length of the packet acquired in the discrimination result, the process of step 4 [FIG. 2: S4] is executed in step 5 [FIG. 2: S5]. If the process proceeds to the process and the UDP data length of the packet acquired in the determination result does not correspond to 20 bytes or more, the process in step 4 [FIG. 2: S4] transitions to the process in step 8 [FIG. 2: S8].

<Step 5 [FIG. 2: S5]>
In step 5 [FIG. 2: S5], assuming that the acquired packet is a VoIP packet, the data corresponding to the version of the RTP header in the transport data (UDP payload) is extracted. It is determined whether the version of the RTP header in the acquired transport data (UDP payload) of the packet is the currently used version. Step 5 [FIG. 2: S5] is processed by the transport header acquisition unit [FIG. 1:14] and the packet discrimination unit [FIG. 1:16].

  An example of specific determination processing in step 5 [FIG. 2: S5] is as follows. When the bit information acquisition unit [FIG. 1:15] has layer-structure 43 to 54 (or option: contributing source (CSRC) identifier) in layer 2 [FIG. 3:31] of the acquired packet. The structure of layer 2 is 43 to 58) (bytes) [FIG. 3: 35] from the head of 1 (byte), and from the top of this 1 (byte) is 1 to 2 (bit) (: 8 to 7 (bit). ) (FIG. 7: 71) is extracted. The packet discriminating unit [FIG. 1: 16] discriminates whether the extracted data corresponds to 2 in the version of the RTP header of the acquired packet. When the RTP header version of the packet acquired in the discrimination result corresponds to 2 in the discrimination result, the packet discrimination unit [FIG. 1: 16] performs the process in step 5 [FIG. 2: S5] in step 6 [FIG. 2: S6]. If the RTP header version of the packet acquired in the determination result does not correspond to 2, the process of step 5 [FIG. 2: S5] transitions to the process of step 8 [FIG. 2: S8]. (Note that the option: contribution sender (CSRC) identifier is 13 to 35 (bytes) of the structure of layer 2 in the layer 2 [FIG. 3:31] of the acquired packet. 16 (byte) data [FIG. 7: 72].)

<Step 6 [FIG. 2: S6]>
Step 6 [FIG. 2: S6] assumes that the acquired packet is a VoIP packet, and extracts and extracts the data corresponding to the most significant bit of the payload type in the transport data (UDP payload) It is determined whether the media type of the RTP payload type in the transport data (UDP payload) of the packet from which the data is acquired includes voice [0 in the most significant bit of the payload type]. Step 6 [FIG. 2: S6] is processed by the bit information acquisition unit [FIG. 1:15] and the packet discrimination unit [FIG. 1:16].

  An example of specific determination processing in step 6 [FIG. 2: S6] is as follows. When the bit information acquisition unit [FIG. 1:15] has layer-structure 43 to 54 (or option: contributing source (CSRC) identifier) in layer 2 [FIG. 3:31] of the acquired packet. Layer 2 structure 43 to 58) (bytes) [FIG. 3: 35] from the top of the 2 (bytes), 2 (bits) from the top of the 2 (bytes) (corresponding to 7 (bits)) Data [FIG. 7: 73] is extracted. The packet discriminating unit [FIG. 1: 16] discriminates whether the extracted data corresponds to 0 in the most significant bit of the payload type in the transport data (UDP payload) of the acquired packet. When the most significant bit of the payload type in the transport data (UDP payload) of the packet acquired in the determination result corresponds to 0, the packet determination unit [FIG. 1: 16] performs the process of step 6 [FIG. 2: S6]. Transitions to the processing of step 7 [FIG. 2: S8], and when the most significant bit of the payload type in the transport data (UDP payload) of the packet acquired in the determination result does not correspond to 0, step 6 [FIG. 2: The process of S6] transitions to the process of step 8 [FIG. 2: S8].

<Step 7 [FIG. 2: S7]>
Step 7 [FIG. 2: S7] assumes that the acquired packet is a VoIP packet, extracts the data corresponding to the padding in the transport data (UDP payload), and the extracted data It is determined whether there is no padding in the information related to padding in the transport data (UDP payload). Step 7 [FIG. 2: S7] is processed by the bit information acquisition unit [FIG. 1:15] and the packet discrimination unit [FIG. 1:16].

  An example of specific determination processing in step 7 [FIG. 2: S7] is as follows. When the bit information acquisition unit [FIG. 1:15] has layer-structure 43 to 54 (or option: contributing source (CSRC) identifier) in layer 2 [FIG. 3:31] of the acquired packet. , 43 to 58) (bytes) [FIG. 3: 35] from the top, 1 (byte) from the top of this 1 (byte), data of 3 [bit] (corresponding to: 6 (bit)) [FIG. : 74] is extracted. The packet discriminating unit [FIG. 1: 16] discriminates whether or not the extracted data corresponds to 0 in the padding in the transport data (UDP payload) of the acquired packet. When the padding in the transport data (UDP payload) of the packet acquired in the discrimination result corresponds to 0, the packet discriminating unit [FIG. 1:16] performs the processing in step 7 [FIG. 2: S7] in step 9 [FIG. 2: When the process transits to S9 and the padding in the transport data (UDP payload) of the packet acquired in the determination result does not correspond to 0, the process of step 7 [FIG. 2: S7] is performed in step 8 [FIG. : Transition to the process of S8].

<Step 8 [FIG. 2: S8]>
Step 8 [FIG. 2: S8] determines that the acquired packet is not an RTP packet when all the determination conditions of Step 1 [FIG. 2: S1] to Step 1 [FIG. 2: S7] do not apply, and the packet The processing related to is performed by a procedure other than the RTP packet. Step 8 [FIG. 2: S8] is processed by the packet discrimination unit [FIG. 1:16] and the packet processing unit [not shown].

  An example of specific determination processing in step 8 [FIG. 2: S8] is as follows. The packet discriminating unit [FIG. 1: 16] discriminates that the packet is not an RTP packet when all the judgment conditions in step 1 [FIG. 2: S1] to step 1 [FIG. 2: S7] do not apply, and the packet processing unit [Not shown] performs processing related to the packet by a procedure other than the RTP packet.

  If it is assumed in step 1 [FIG. 2: S1] to step 7 [FIG. 2: S7] that the acquired packet is RTP, further steps 9 [FIG. 2: S9] to step 16 [FIG. 2: S16] are performed. , It is determined that the acquired packet corresponds to RTP, and the type of RTP in the acquired packet is determined. The type of RTP to be determined is whether or not there is an extension of the RTP header and the codec / payload length used for RTP. Regarding the codec / payload length used for RTP, G.D. 711 and payload length: RTP that is a multiple of 8 bytes, or codec: G.E. 729 and payload length: RTP that is a multiple of 10 bytes, or other RTP other than the above is determined.

<Step 9 [FIG. 2: S9]>
Step 9 [FIG. 2: S9] assumes that the acquired packet is a VoIP packet, and extracts and extracts data corresponding to information on the extension header of the RTP header in the transport data (UDP payload). It is determined whether there is an extension header in the information related to the extension header of the RTP header of the packet from which the acquired data is acquired. Step 9 [FIG. 2: S9] is processed by the bit information acquisition unit [FIG. 1:15] and the packet discrimination unit [FIG. 1:16].

  An example of a specific determination process in step 9 [FIG. 2: S9] is as follows. When the bit information acquisition unit [FIG. 1:15] has layer-structure 43 to 54 (or option: contributing source (CSRC) identifier) in layer 2 [FIG. 3:31] of the acquired packet. , Layer 2 structure 43 to 58) (bytes) [FIG. 7: 35] from the head of 1 (byte), 4 (bit) from the top of this 1 (byte) (corresponding to: 5 (bit)) (FIG. 7: 75) is extracted. The packet discriminating unit [FIG. 1: 16] discriminates whether or not the extracted data corresponds to 1 in the information related to the extension header of the RTP header in the transport data (UDP payload) of the acquired packet. When the information about the extension header of the RTP header in the transport data (UDP payload) of the packet acquired in the discrimination result corresponds to 1, the packet discriminator [FIG. 1: 16] performs step 9 [FIG. 2: S9]. The process transitions to the process of step 10 [FIG. 2: S10]. If the information related to the extension header of the RTP header in the transport data (UDP payload) of the packet acquired in the determination result does not correspond to 1, the process of step 9 [FIG. 2: S9] transitions to step 11 [FIG. 2: S11].

<Step 10 [FIG. 2: S10]>
Step 10 [FIG. 2: S10] determines that the acquired packet has an extension header in the RTP header in the transport data (UDP payload), and determines “UDP data size in the transport data (UDP payload) of the acquired packet. "-" 16 bytes "is determined to be the size of the RTP payload, and the process of step 12 is performed. Step 10 [FIG. 2: S10] is processed by the packet discrimination unit [FIG. 1:16].

  An example of specific processing in Step 10 [FIG. 2: S10] is as follows. The packet discriminating unit [FIG. 1:16] has a value of “UDP data size” − “16 bytes” in the transport data (UDP payload) of the packet acquired by the transport header information acquiring unit [FIG. 1:14]. The size of the RTP payload [FIG. 3: 36] is determined, and the process of step 10 [FIG. 2: S10] transitions to the process of step 12 [FIG. 2: S12].

<Step 11 [FIG. 2: S11]>
Step 11 [FIG. 2: S11] determines that there is no extension header in the RTP header in the transport data (UDP payload) in the acquired packet, and “UDP data in the transport data (UDP payload) in the acquired packet” It is determined that the value of “size” − “12 bytes” is the size of the RTP payload, and the process of step 12 is performed. Step 11 [FIG. 2: S10] is processed by the packet discrimination unit [FIG. 1:16].

  An example of specific processing in step 11 [FIG. 2: S11] is as follows. The packet discriminating unit [FIG. 1:16] indicates that the value of “UDP data size” − “12 bytes” in the packet transport data (UDP payload) acquired by the transport header information acquiring unit [FIG. 1:14] is RTP. It is determined that the size is the payload [FIG. 3: 36], and the process of step 11 [FIG. 2: S11] transitions to the process of step 12 [FIG. 2: S12].

<Step 12 [FIG. 2: S12]>
In step 12 [FIG. 2: S12], assuming that the acquired packet is a VoIP packet, the data corresponding to the RTP payload in the transport data (UDP payload) is extracted, and the extracted data is acquired. In the RTP payload data in the packet transport data (UDP payload), the VoIP packet codec is G. 711 is determined. Step 12 [FIG. 2: S12] is processed by the bit information acquisition unit [FIG. 1:15] and the packet discrimination unit [FIG. 1:16].

  An example of specific processing in step 12 [FIG. 2: S12] is as follows. When the bit information acquisition unit [FIG. 1:15] has layer-structure 43 to 54 (or option: contributing source (CSRC) identifier) in layer 2 [FIG. 3:31] of the acquired packet. , 43 to 58) (bytes) [FIG. 7: 35], 2 (bytes) from the top, and 2 to 8 [bits] (corresponding to: 7 to 1 (bit)) from the top of these 2 (bytes) Data [FIG. 7: 73] is extracted. The packet discriminating unit [FIG. 1: 16] uses G.D. in the payload type (encoding name) of the RTP payload in the transport data (UDP payload) of the packet acquired by the extracted data. It is determined whether it corresponds to 711 (: value is 0). The packet discriminating unit [FIG. 1:16] indicates that the encoding name of the RTP payload in the transport data (UDP payload) of the packet acquired in the discrimination result is G. If it does not correspond to 711 (: value 0), the process of step 12 [FIG. 2: S12] transitions to the process of step 13 [FIG. 2: S13], and the transport data (UDP) of the packet acquired in the discrimination result GTP in the encoding name of the RTP payload in the payload). In the case of 711 (: value is 0), the process of step 12 [FIG. 2: S12] transitions to the process of step 14 [FIG. 2: S14].

<Step 13 [FIG. 2: S13]>
Step 13 [FIG. 2: S13] assumes that the acquired packet is a VoIP packet, extracts the data corresponding to the RTP payload in the transport data (UDP payload), and the extracted data is acquired. In the RTP payload data in the packet transport data (UDP payload), the VoIP packet codec is G. 729 is determined. Step 13 [FIG. 2: S13] is processed by the bit information acquisition unit [FIG. 1:14], the packet discrimination unit [FIG. 1:16], and the packet discrimination unit [FIG. 1:16].

  An example of specific determination processing in step 13 [FIG. 2: S13] is as follows. When the bit information acquisition unit [FIG. 1:15] has layer-structure 43 to 54 (or option: contributing source (CSRC) identifier) in layer 2 [FIG. 3:31] of the acquired packet. , 43 to 58) (bytes) [FIG. 7: 35], 2 (bytes) from the top, and 2 to 8 [bits] (corresponding to: 7 to 1 (bit)) from the top of these 2 (bytes) Data [FIG. 7: 73] is extracted. The packet discriminating unit [FIG. 1:16] indicates that the payload type (encoding name) of the RTP payload in the transport data (UDP payload) of the packet acquired by the extracted data is G. 729 (: value is 18). The packet discriminating unit [FIG. 1:16] indicates that the encoding name of the RTP payload in the transport data (UDP payload) of the packet acquired in the discrimination result is G. 729 (: value is 18), the process of step 13 [FIG. 2: S13] transitions to the process of step 15 [FIG. 2: S15], and the packet transport data (UDP) acquired in the discrimination result RTP payload encoding name in G. If it does not correspond to 729 (: value is 18), the process of step 13 [FIG. 2: S13] transitions to the process of step 16 [FIG. 2: S16].

<Step 14 [FIG. 2: S14]>
In step 14 [FIG. 2: S14], the acquired packet is RTP and the codec of the acquired packet is established by ITU-T. 711 and it is determined that the payload length is a multiple of 8 bytes. Step 14 [FIG. 2: S14] is processed by the packet discrimination unit [FIG. 1:16] and the packet processing unit [not shown].

  An example of specific processing in step 14 [FIG. 2: S14] is as follows. The packet discriminating unit [FIG. 1: 16] is a G.D. 711, the payload length is determined to be a multiple of 8 bytes, and the packet processing unit [not shown] performs processing related to the acquired packet in the codec: ITU-T. 711, Payload length: Performs priority control processing corresponding to RTP of multiple bytes of 8.

<Step 15 [FIG. 2: S15]>
In step 15 [FIG. 2: S15], the acquired packet is RTP and the codec of the acquired packet is established by ITU-T. 729 and it is determined that the payload length is a multiple of 10 bytes. Step 15 [FIG. 2: S15] is processed by the packet discrimination unit [FIG. 1:16] and the packet processing unit [not shown].

  An example of specific processing in step 15 [FIG. 2: S15] is as follows. The packet discriminating unit [FIG. 1: 16] is a G.D. 729, the payload length is determined to be a multiple of 10 bytes, and the packet processing unit [not shown] determines the processing related to the acquired packet by the codec: ITU-T. 729, Payload length: Priority control processing corresponding to RTP of multiple bytes of 10 is performed.

<Step 16 [FIG. 2: S16]>
Step 16 [FIG. 2: S16] determines that the acquired packet is RTP and other RTP than the above. Step 16 [FIG. 2: S16] is processed by the packet discrimination unit [FIG. 1:16] and the packet processing unit [not shown].

  An example of specific processing in step 16 [FIG. 2: S16] is as follows. The packet discriminating unit [FIG. 1: 16] discriminates that the acquired packet is other RTP, and the packet processing unit [not shown] supports processing related to the acquired packet for other RTPs other than the above. Priority control processing is performed.

(A-3) Effect of First Embodiment As described above, packet discrimination in the network device according to the first embodiment of the present invention includes a function of reading a data link header of a packet, a function of reading a network header, By providing a function of reading a transport header and a function of acquiring an arbitrary bit in a packet, it is possible to determine with high accuracy that one packet is an RTP packet.

It is a block diagram which shows the structure of packet discrimination | determination of the network device in the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement of packet discrimination | determination in the network device in the 1st Embodiment of this invention. It is the structure of the layer 2 when a packet is VoIP in the 1st Embodiment of this invention. 3 is a structure of a MAC header (Ethernet (registered trademark) V2 format) when a packet is VoIP in the first embodiment of the present invention. It is the structure of the IP header when the packet is VoIP in the first embodiment of the present invention. It is a structure of a UDP header when the packet is VoIP in the first embodiment of the present invention. FIG. 5 is a structure of an RTP header in UDP data when a packet is VoIP in the first embodiment of the present invention. FIG.

Explanation of symbols

1 RTP packet discrimination device.
11: Packet acquisition unit.
12: Data link header The acquisition unit.
13: Network header information acquisition unit.
14: Transport header information acquisition unit.
15: Bit information acquisition unit.
16: Packet discrimination unit.
31: Layer 2 structure of the acquired packet.
32 ... Data of 1 to 14 (bytes) in the layer 2 structure of the acquired packet (data link header information (14 bytes)).
33 ... Data of 15 to 34 (bytes) in the layer 2 structure of the acquired packet (network header information (20 bytes)).
34: Data of 35 to 42 (bytes) in the layer 2 structure of the acquired packet (transport header information (8 bytes)).
35 ... 43 to 54 in the layer 2 structure of the acquired packet (or, if there is a contributing source (CSRC) identifier, 43 to 58 in the layer 2 structure) (bytes) data (RTP header) Information (12-16 bytes)).
36 ... 55-62 (maximum: 214) in the layer 2 structure of the acquired packet (or, if there is an optional: contributing source (CSRC) identifier, 59-66 (maximum: 218) in the layer 2 structure )) (Byte) data (RTP payload (8 to 160 bytes)).
41... Data (destination MAC address header) of 1 to 6 (bytes) from the beginning of 1 to 14 (bytes) in the layer 2 structure of the acquired packet.
51... Data (protocol) of 10 (bytes) from the head of 15 to 34 (bytes) in the layer 2 structure of the acquired packet.
61: Data of 3 to 4 (bytes) from the head of 35 to 42 (bytes) in the layer 2 structure of the acquired packet (source port number).
62 ... Data (destination port number) of 5 to 6 (bytes) from the head of 35 to 42 (bytes) in the layer 2 structure of the acquired packet.
71 ... 43 to 54 in the layer 2 structure of the acquired packet (or option: when there is a contributing transmission source (CSRC) identifier, 43 to 58 in the structure of layer 2) (bytes) from the top of 1 ( 1) to 2 (bit) (corresponding to 8 to 7 (bit)) from the top of this 1 (byte) (V: version).
72 ... Data of 13 to 16 (bytes) from the beginning of 43 to 58 (bytes) in the layer 2 structure of the acquired packet (contributing transmission source (CSRC) identifier (optional)).
73 ... 43 to 54 in the layer 2 structure of the acquired packet (or option: when there is a contributing transmission source (CSRC) identifier, 43 to 58 in the structure of layer 2) 2 (from the top of the byte) 2 to 8 (bit) (corresponding to 7 to 1 (bit)) from the top of 2 (byte) (payload type).
74 ... 43 to 54 in the layer 2 structure of the acquired packet (or optional: 43 to 58 when there is a contributing transmission source (CSRC) identifier), 1 (byte) from the head of (byte), Data (P: padding) of 3 [bit] (corresponding to: 6 (bit)) from the top of this 1 (byte).
75 ... 43 to 54 in the layer 2 structure of the acquired packet (or option: 43 to 58 when there is a contributing transmission source (CSRC) identifier), 1 (byte) from the head of (byte), Data (X: extended) of 4 (bit) (corresponding to: 5 (bit)) from the top of this 1 (byte).

Claims (22)

Assuming that the input packet is a packet containing an audio signal, in the packet discrimination device for discriminating the type of the packet in layer 2 of the packet,
A first acquisition unit for acquiring data link header information of the packet;
A second acquisition unit for acquiring network header information of the packet;
A third acquisition unit for acquiring transport header information of the packet;
A fourth acquisition unit that acquires information of an arbitrary bit of the packet;
Based on the information acquired by the first acquisition unit, the second acquisition unit, the third acquisition unit, and the fourth acquisition unit, the packet is an RTP (Real-time Transport Protocol) packet. A packet discrimination device comprising: a packet discrimination unit for discriminating whether or not. The packet discrimination device according to claim 1,
The packet discrimination unit
The data acquired by the first acquisition unit is such that the destination MAC address header is not a multicast address or a broadcast address,
The data acquired by the second acquisition unit is UDP in the data format of the packet,
The data acquired by the third acquisition unit is a port number used in RTP,
The data acquired by the third acquisition unit is not less than the minimum size of RTP in the UDP data length,
The data acquired by the fourth acquisition unit is a version currently used in the version of the RTP header,
The data acquired by the fourth acquisition unit is such that the media type includes sound,
When the data acquired by the fourth acquisition unit has no padding in the packet,
A packet discrimination device for discriminating that the packet is an RTP packet. The packet discrimination device according to claim 1,
The first acquisition unit includes:
Assuming that the packet is a packet including a voice signal, the first data of a portion corresponding to a destination MAC (Media Access Control) address header of the data link header information is extracted.
The packet discrimination unit
The packet discriminating apparatus, wherein the first data discriminates that the destination MAC address header is not a multicast address or a broadcast address. The packet discrimination device according to claim 1,
The second acquisition unit includes:
Assuming that the packet is a packet including a voice signal, the second data of the portion corresponding to the protocol of the network header information is extracted,
The packet discrimination unit
A packet discriminating apparatus characterized by discriminating that the second data is UDP (User Datagram Protocol) in the data format of the packet. The packet discrimination device according to claim 1,
The third acquisition unit includes:
Assuming that the packet is a packet containing an audio signal, the third data of the portion corresponding to the destination port of the UDP header of the transport header information is extracted,
The packet discrimination unit
A packet discrimination device characterized by discriminating that the third data is a port number used in RTP. The packet discrimination device according to claim 1,
The third acquisition unit includes:
Assuming that the packet is a packet containing an audio signal, extract the fourth data of the portion corresponding to the UDP data length of the transport header information,
The packet discrimination unit
It is determined that the fourth data is equal to or larger than the minimum size of RTP in the UDP data length. The packet discrimination device according to claim 1,
The fourth acquisition unit includes:
Assuming that the packet is a packet including an audio signal, the fifth data of the portion corresponding to the version of the RTP header in the transport data is extracted,
The packet discrimination unit
The packet discrimination device characterized in that the fifth data is a version currently used in the version of the RTP header. The packet discrimination device according to claim 1,
The fourth acquisition unit includes:
Assuming that the packet is a packet including an audio signal, the sixth data of the portion corresponding to the most significant bit of the payload type in the transport data is extracted,
The packet discrimination unit
The packet discriminating apparatus, wherein the sixth data discriminates that the media type includes voice. The packet discrimination device according to claim 1,
The fourth acquisition unit includes:
Assuming that the packet is a packet including an audio signal, the seventh data of the portion corresponding to the padding in the transport data is extracted,
The packet discrimination unit
The packet discriminating apparatus, wherein the seventh data discriminates that there is no padding in the packet. The packet discrimination device according to claim 1,
The fourth acquisition unit includes:
Assuming that the packet is a packet including a voice signal, the eighth data of the portion corresponding to the information on the extension header of the RTP header in the transport data of the packet is extracted;
The packet discrimination unit
A packet discriminating apparatus that discriminates a size of an RTP payload in the packet based on the eighth data. The packet discrimination device according to claim 10, wherein
The fourth acquisition unit includes:
Assuming that the packet is a packet including an audio signal, the ninth data of the portion corresponding to the RTP payload in the transport data of the packet is extracted;
The packet discrimination unit
A packet discrimination device that discriminates the type of RTP in the packet based on the eighth data. Assuming that the input packet is a packet containing an audio signal, in the packet discrimination method for discriminating the type of the packet in layer 2 of the packet,
A first acquisition step of acquiring data link header information of the packet;
A second acquisition step of acquiring network header information of the packet;
A third acquisition step of acquiring transport header information of the packet;
A fourth acquisition step of acquiring information of an arbitrary bit of the packet,
Based on the information acquired in the first acquisition step, the second acquisition step, the third acquisition step, and the fourth acquisition step, the packet is an RTP (Real-time Transport Protocol) packet. A packet discrimination method comprising: a packet discrimination step for discriminating whether or not. The packet discrimination method according to claim 12,
The packet discrimination step includes
The data acquired in the first acquisition step is such that the destination MAC address header is not a multicast address or a broadcast address,
The data acquired in the second acquisition step is UDP in the data format of the packet,
The data acquired in the third acquisition step is a port number used in RTP,
The data acquired in the third acquisition step is not less than the minimum size of RTP in the UDP data length,
The data acquired in the fourth acquisition step is the version currently used in the version of the RTP header;
The data acquired in the fourth acquisition step is such that the media type includes sound,
When the data acquired in the fourth acquisition step has no padding in the packet,
A packet discrimination method comprising: discriminating that the packet is an RTP packet. The packet discrimination method according to claim 12,
The first acquisition step includes:
Assuming that the packet is a packet including a voice signal, the first data of a portion corresponding to a destination MAC (Media Access Control) address header of the data link header information is extracted.
The packet discrimination step includes
The packet discrimination method, wherein the first data discriminates that the destination MAC address header is not a multicast address or a broadcast address. The packet discrimination method according to claim 12,
The second obtaining step includes
Assuming that the packet is a packet including a voice signal, the second data of the portion corresponding to the protocol of the network header information is extracted,
The packet discrimination step includes
A packet discrimination method comprising: discriminating that the second data is UDP (User Datagram Protocol) in a data format of the packet. The packet discrimination method according to claim 12,
The third obtaining step includes
Assuming that the packet is a packet containing an audio signal, the third data of the portion corresponding to the destination port of the UDP header of the transport header information is extracted,
The packet discrimination step includes
A packet discrimination method characterized by discriminating that the third data is a port number used in RTP. The packet discrimination method according to claim 12,
The third obtaining step includes
Assuming that the packet is a packet containing an audio signal, extract the fourth data of the portion corresponding to the UDP data length of the transport header information,
The packet discrimination step includes
It is determined that the fourth data is not less than the minimum size of RTP in the UDP data length. The packet discrimination method according to claim 12,
The fourth acquisition step includes:
Assuming that the packet is a packet including an audio signal, the fifth data of the portion corresponding to the version of the RTP header in the transport data is extracted,
The packet discrimination step includes
It is determined that the fifth data is a version currently used in the version of the RTP header. The packet discrimination method according to claim 12,
The fourth acquisition step includes:
Assuming that the packet is a packet including an audio signal, the sixth data of the portion corresponding to the most significant bit of the payload type in the transport data is extracted,
The packet discrimination step includes
A packet discrimination method, wherein the sixth data discriminates that the media type includes voice. The packet discrimination method according to claim 12,
The fourth acquisition step includes:
Assuming that the packet is a packet including an audio signal, the seventh data of the portion corresponding to the padding in the transport data is extracted,
The packet discrimination step includes
The packet discriminating method, wherein the seventh data discriminates that there is no padding in the packet. The packet discrimination method according to claim 12,
The fourth acquisition step includes:
Assuming that the packet is a packet including a voice signal, the eighth data of the portion corresponding to the information on the extension header of the RTP header in the transport data of the packet is extracted;
The packet discrimination step includes
A packet discrimination method, comprising: discriminating a size of an RTP payload in the packet based on the eighth data. The packet discrimination method according to claim 21, wherein
The fourth acquisition step includes:
Assuming that the packet is a packet including an audio signal, the ninth data of the portion corresponding to the RTP payload in the transport data of the packet is extracted;
The packet discrimination step includes
A packet discrimination method, comprising: discriminating an RTP type in the packet based on the eighth data.

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