JP6001516B2 - Communication system and communication apparatus - Google Patents

Description

The present invention relates to a communication system and a communication apparatus, and more particularly, to a communication system and a communication apparatus that control a delay amount when passing through a transmission network for each control signal / data signal.

With the spread of PCs and mobile terminals, development of information services using the Internet, such as information distribution services on the Web, TV, radio broadcasting, IP phones and SNSs, is accelerating. With the increase in the number of users and the enrichment of contents on the Internet, communication infrastructures are required to have larger capacity, higher reliability, and a higher level of safety. In particular, the use of the Internet for commercial purposes has increased, and the proportion of online commerce for consumption activities has been increasing year by year. In communication infrastructure, in addition to stable operation of communication systems, information leakage, alteration, impersonation, etc. It is important to design a function that assumes various user activities including right and wrong.
One of the measures for promoting the user's use of the Internet under such circumstances is ensuring fairness. In an IP network such as the Internet, the best effort type packet processing is fundamental. Therefore, for example, two users connect to the Internet from a geographically distant location using a mobile terminal, and at the same time, information distribution requests and ordering / ordering (in commercial transactions) to the same information server. Even when processing is performed, the information server and each user terminal generated due to differences in the physical distance (communication line length) from the information server to the two and the packet processing capability of the signal relay device (IP router, L2 switch, etc.) It is assumed that the service reception time in the information server is different due to the difference in communication time. In this way, when the service reception time is different, in most cases, the service is provided on a first-come-first-served basis. Therefore, it is assumed that unfairness occurs between users due to the difference in communication time caused by this geographical condition.
Under such circumstances, methods for reducing the unfairness that depends on this network are being studied. The Quality of Service (hereinafter referred to as QoS) function provided in IP routers and L2 switches, etc., identifies high priority traffic from many traffic flowing through the network, and prioritizes the traffic in the network. A technique is known such as reducing the delay difference by passing the packet (processing the corresponding packet with priority in each communication device).
In addition, as described in Patent Document 1, in a network connecting a user and an information server, a communication device installed at a position close to the user receives a time at which the packet is transmitted to the information server issued by the user. A technique is known in which the time stamp is given as a time stamp, and the order of transfer to the outside of the network is changed by referring to the time stamp in the packet by another communication apparatus installed at a position close to the server side. Further, in Patent Document 1, in order to provide fairness in the delay time of the network, the destination is set after the delay time of the network set in advance for each transmission source from the reception time of the network in the apparatus installed near the server side. The technique of sending to is disclosed.

JP 2012-199728 A

In Patent Document 1, even if the time at which a user-issued packet arrives at a communication device close to the server is delayed from the expected time due to the occurrence of unexpected congestion in packet processing inside the network, Therefore, the time required for the packet to pass through the network may be longer than usual. Conversely, if a packet reaches a communication device closer to the server earlier than the expected time due to a change in the priority of packet processing inside the network or a decrease in the number of communication devices that pass through due to a route change, the packet Time to pass through the network is faster than usual. Thus, there is a problem that the delay time required for the packet to pass cannot be made constant.
Further, in Patent Document 1, sequence information including time information is given when a communication device close to the user transmits a packet into the network. In this case, time information and order information are also given to packets that are irrelevant to the fairness of the delay time, represented by best-effort data communication such as Web content. Extra bandwidth is required. In addition, in the communication device close to the server side that receives the packet, delay is added to all the packets, so that the packet residence time in the network is long and the traffic processing efficiency may be reduced. Furthermore, in a communication device close to the server side, in order to avoid service stagnation due to increased delay, processing must be performed with a certain fixed time as the upper limit of the packet retention time. There is a possibility that the packet that becomes will be discarded. At this time, a case where a packet unrelated to fairness is included is also assumed.

In view of the above points, an object of the present invention is communication that can ensure high fairness by stabilizing the delay time even when the communication section includes a best effort network in which it is difficult to guarantee the delay time. A system and a communication device are provided. Another object of the present invention is to provide a communication system and a communication apparatus having a delay control function that ensures fairness and at the same time does not reduce the processing efficiency of traffic that does not require fairness, such as best effort communication. It is.

According to the first solution of the present invention,
A communication system,
A first communication device interconnecting the first network or the first device and the transmission network;
A second network or a second communication device interconnecting the second device and the transmission network;

The first communication device is:
When the first specific packet to be subjected to delay control is extracted from the packet received from the first network or the first device, the time when the first specific packet is received is set as the time stamp time in the first specific packet. A receiving packet processing unit for inserting the first packet to the transmission network,

The second communication device is:
A transmission packet extraction unit that extracts the first packet including the time stamp time from a packet received from the transmission network;
A time stamp time is read from the first specific packet extracted by the transmission packet extracting unit, and the time when the first specific packet is received from a predetermined delay time in the transmission network and the time stamp A delay controller for subtracting a time difference from the time to calculate an additional delay time, and holding the first specific packet until the additional delay time elapses;
A priority control unit configured to receive the first specific packet from the delay control unit when the additional delay time has elapsed and to transmit the first specific packet in preference to other packets; A communication system is provided.

According to the second solution of the present invention,
A communication device,
When interconnecting the first network or the first device and the transmission network,
When the first specific packet to be subjected to delay control is extracted from the packet received from the first network or the first device, the time when the first specific packet is received is set as the time stamp time in the first specific packet. A receiving packet processing unit for inserting the first packet to the transmission network,

When interconnecting a second network or a second device and the transmission network,
A transmission packet extraction unit that extracts the first packet including the time stamp time from a packet received from the transmission network;
A time stamp time is read from the first specific packet extracted by the transmission packet extracting unit, and the time when the first specific packet is received from a predetermined delay time in the transmission network and the time stamp A delay controller for subtracting a time difference from the time to calculate an additional delay time, and holding the first specific packet until the additional delay time elapses;
A priority control unit configured to receive the first specific packet from the delay control unit when the additional delay time has elapsed and to transmit the first specific packet in preference to other packets; A communication device is provided.

According to the present invention, it is possible to provide a communication system and a communication apparatus that can ensure high fairness by stabilizing the delay time even when the communication section includes a best effort network in which it is difficult to guarantee the delay time. it can. In addition, according to the present invention, it is possible to provide a communication system and a communication apparatus having a delay control function that ensures fairness and at the same time does not reduce the processing efficiency of traffic that does not require fairness, such as best effort communication.

It is a network diagram which shows the basic structural example of the communication system in a present Example. It is a functional block diagram which shows the function structural example of a delay equalization control apparatus (2-1, 2-2, 2-3). It is an example of a structure of the user line control interface part installed in the user side edge of a transmission network. It is an example of a structure of the user line control interface part installed in the server side edge of a transmission network. It is an example of a structure of the network line control interface part in a present Example. 4 is a flowchart showing a flow of processing for a packet received from the user side in the received packet processing unit 202 of FIG. 3. 5 is a flowchart showing a flow of processing for a packet received from the transmission network 5 side by a transmission packet processing unit 205 in FIG. 4. It is an example of the timer expiration process flowchart of the transmission packet process part in a present Example. It is an example of the time grant packet determination table in a present Example. It is an example of the packet provided with the time stamp information in a present Example. It is an example of the delay packet transmission process flowchart of the measurement packet insertion part in a present Example. It is an example of the received packet distribution process flowchart of the packet distribution control part in a present Example. It is an example of the delay packet reception process flowchart of the delay time calculation part in a present Example. It is an example of the transmission information management table in a present Example. It is an example of the measurement time management table in a present Example. It is an example of the flowchart of the network delay time determination process of the apparatus management part in a present Example. It is an example of the schematic sequence of the delay time measurement in a present Example. 6 is an example of a timing chart for explaining equalization between different users when the delay equalization network of the first embodiment is applied. 3 is an example of a timing chart for explaining a difference depending on a packet type when the delay equalization network of the first embodiment is applied. 10 is an example of a delay time management table in Embodiment 2. 9 is an example of a transmission packet processing flowchart of a transmission packet processing unit in the second embodiment. 6 is an example of a timing chart for explaining a difference depending on a packet type when the delay equalization network of the second embodiment is applied. 6 is a flowchart showing a flow of packet transmission processing in the priority control unit 2054 of FIG. 4. It is an example of the priority transmission time management table in a present Example.

A. Overview

According to this embodiment, in order to solve the above problem,
In a communication system for connecting the first and second networks to each other via a transmission network,
A delay equalization control device having a function of interconnecting the first network and the transmission network or the second network and the transmission network;
A timing synchronization unit that synchronizes the device internal time with the external reference timing information;
A received packet extraction unit that extracts a specific packet type from a packet received by the delay equalization control device from the first network;
A time stamp unit that obtains the time when the first specific packet extracted by the packet extraction unit is received from the device internal time information synchronized with the external reference clock by the timing synchronization unit, and inserts the time into the specific packet When,
A transmission packet extraction unit that extracts a packet including the device internal time information from a packet received by the delay equalization control device from the transmission network;
The time stamp information is read from the second specific packet extracted by the packet extraction unit, the relay start time extracted from the read time stamp information, and set in the delay equalization control device by an external setting terminal, Comparing the external transmission time with the designated delay time in the transmission network with the device internal time synchronized by the timing synchronization unit, and calculating the additional delay time in which the second specific packet should be held in the device A delay adjusting unit that holds the packet until the additional delay time elapses;
It can be characterized by comprising.

B. First embodiment

1. system

FIG. 1 is a network diagram showing a basic configuration example of a communication system in the present embodiment. The transmission network 5 is a transmission network provided by a telecommunications carrier, and this embodiment realizes equalization of delay time for the network 5. In this specification, this network 5 may be called a delay equalization network.
As shown in the figure, the transmission network 5 includes intermediate nodes 4-1 and 4-2 and delay equalization control devices 2-1, 2-2 and 2-3 described in the present specification. Transmission devices used in the intermediate nodes 4-1 and 4-2 are general transmission devices such as an IP router and an L2 switch. Delay equalization control devices 2-1, 2-2, and 2-3 are arranged at boundaries connecting other access networks 6-1, 6-2 and 6-3 and the network 5. Further, the user terminals 1-1 and 1-2 and the server 3 are connected under the access networks 6-1, 6-2 and 6-3. In the network configuration example in this figure, the delay equalization control devices 2-1, 2-2, and 2-3 are communication devices installed at the boundary of the transmission network 5 provided by the communication carrier. It is good also as a communication apparatus which the communication carrier installed in a subscriber's house manages.
In this figure, the user A uses the user terminal 1-1 to access the server 3 via the access network A6-1, the transmission network 5, and the access network C6-3 in this order. When the user A passes through the transmission network 5, the user A passes through the intermediate node A4-1 and the intermediate node B4-2. Similarly, the user B uses the user terminal 1-2 to access the server 3 via the access network 6-2, the transmission network 5, and the access network 6-3 in this order. When the user B goes through the transmission network 5, the user B goes through the intermediate node B4-2, not through the intermediate node A4-1. For this reason, when accessing normally, it is assumed that the delay time of communication required for the user A to pass through the transmission network 5 is longer than the user B.

2. Delay equalization control device

2-1. Functional Block FIG. 2 is a functional block diagram showing a functional configuration example of the delay equalization control device (2-1, 2-2, 2-3).
The delay equalization control device (2-1, 2-2, 2-3. Hereinafter, the delay equalization control device 2 will be referred to as a delay equalization control device 2 when referring to them collectively) is a device control that manages the delay equalization control device 2 as a whole. Unit 10, user circuit control interface unit 20 (20-1,..., 20-n) which is an interface on the access network side, and network line control interface unit 21 (21-1,..., 21) which is an interface on the transmission network side. m), an internal switch unit 30 that interconnects them, and a timing synchronization unit 40 that is an interface of an external synchronization signal. The setting terminal 50 shown in the figure is a terminal for setting the delay equalization control device 2, and in this example, is a device outside the scope of the present device. Details of the user circuit control interface unit 20 and the network line control interface unit 21 will be described later.
In the present embodiment, the delay equalization control devices 2-1 and 2-2 send time information (time stamps) to packets that need to be delayed from the access networks 6-1 and 6-2 and enter the transmission network 5, respectively. And transmit to the transmission network 5. The delay equalization control device 2-3 that receives the packet from the transmission network 5 and transmits it to the server 3 side compares the time held by the delay equalization control device 2-3 with the time information (time stamp) in the packet. Thus, the residence time of the packet is determined. As described above, the delay equalization control devices 2-1 and 2-2 on the user side and the delay equalization control device 2-3 on the server 3 side perform a coordinated operation using times recognized by each other. Therefore, it is necessary to synchronize time (at least clock synchronization) between the plurality of delay equalization control devices 2. Details of the packet processing will be described later with reference to FIG.
In order to realize time / clock synchronization (hereinafter referred to as time synchronization), the timing synchronization unit 40 described above uses a time synchronization function such as PTP (Precision Time Protocol) or NTP (Network Time Protocol) defined by IEEE 1588v2. Thus, a function for realizing time synchronization is provided. You may utilize time acquisition functions, such as GPS (Global Positioning System), as a function which implement | achieves time synchronization. The time synchronized with the external time source and the external communication device by the timing synchronization unit 40 is distributed to the user circuit control interface units 20 and 21 in the device through the internal interface 207.

2-2. User circuit control interface unit 20
FIG. 3 shows an example of a functional block configuration of the user circuit control interface unit 20 of the delay equalization control devices 2-1 and 2-2 installed on the user side in the present embodiment. In order to distinguish it from the user circuit control interface unit 20 of the delay equalization control device 2-3 installed on the server side shown in FIG.
The user line control interface unit 20A includes a physical layer (PHY) termination unit 201 that receives packets from the user network interface (hereinafter abbreviated as UNI) side, and a received packet processing unit 202 that performs processing on packets received from the UNI side. In order to perform various settings from the internal switch unit transmission buffer 203 that temporarily stores packets to be transmitted to the internal switch unit, the synchronization timing control IF 207 that is an interface for acquiring time information from the timing synchronization unit 40, and the device control unit 10 CPU interface IF 208, a user line control IF management unit 209 for managing the user line control interface unit, and backup information 200 which is a non-volatile memory for holding setting data. Although not shown in the figure, the user line control interface unit 20A also has a general transfer function for transmitting packets received from the internal switch unit side to the UNI side.
Among these, the received packet processing unit 202 can be realized by a program installed in at least one CPU constituting the received packet extracting unit 2021 and the time stamp unit 2022, and each function is included in each of the functions. It can also be realized as specialized dedicated hardware.
The user line control IF management unit 209 can appropriately reflect various settings performed by the apparatus control unit 10 through the inter-CPU communication IF 208 on the user line control interface unit 20A. In addition, the user line control IF management unit 209 receives the time information, which is synchronized by the timing synchronization unit 40 as described above, via the timing control IF 207, and distributes it to each function in the user line control interface unit 20. Further, the user line control IF management unit 209 stores the information set in the user line control interface unit 20A in the backup information 200, and stores the information using the backup information 200 when the function unit is rebooted. It is possible to return to the autonomous state automatically.
The received packet processing unit 202 in the user line control interface unit 20A described above includes a received packet extraction unit 2021 and a time stamp unit 2022 as functional block units.
These functions realize a function of determining whether or not a condition set in advance for a packet received from the user terminal 1 is met, and adding time information to the matched packet. The received packet extraction unit 2021 determines whether or not the previously set condition is met, and passes the matched packet to the time stamp unit 2022 and the unmatched packet to the internal switch unit reception buffer 203. Process. Conditions set in advance include a condition for specifying a specific connection or service, such as a destination IP address, a destination port number, a VLAN ID, and a protocol type, and a combination thereof. The time stamp unit 2022 performs a process of giving a time synchronized in the apparatus only to a specific packet selected by the received packet extraction unit 2021.

FIG. 4 shows an example of a functional block configuration of the user circuit control interface unit 20 of the delay equalization control apparatus 2-3 installed on the server side in the present embodiment. In order to distinguish from the user circuit control interface unit 20 of the delay equalization control devices 2-1 and 2-2 installed on the user side shown in FIG.
As shown in the figure, the user line control interface unit 20B includes an internal switch unit reception buffer 204 that temporarily stores packets received from the internal switch side, and a transmission packet processing unit 205 that performs processing on the packets received from the internal switch side. In order to perform various settings from the PHY termination unit 206 that performs transmission processing of the physical layer layer of the packet to the UNI side, the synchronization timing control IF 207 that is an interface for acquiring time information from the timing synchronization unit 40, and the device control unit 10 CPU interface IF 208, a user line control IF management unit 209 for managing the user line control interface unit, and backup information 200 which is a non-volatile memory for holding setting data. Although not shown in the figure, the user line control interface unit 20B also has a general transfer function for transmitting a packet received from the UNI side to the internal switch side.
Among these, the transmission packet processing unit 205 can be realized by a program installed in at least one CPU constituting each processing unit, and as dedicated hardware specialized for each function. It can also be realized.
The functional units assigned the same numbers as those already described with reference to FIG. 3 realize the same functions and will not be described.
The transmission packet processing unit 205 in the above-described user line control interface unit 20B includes a transmission packet extraction unit 2051, a delay control unit 2052, and a priority control unit 2054 as functional blocks, and stores them when delaying packets. An adjustment buffer 2053 is provided.
These functions are a delay time set in advance for a packet including time information given by another delay equalization control device 2 when a packet received from the transmission network 5 is sent to the server 3 side. Realize the function to transmit after elapse. The transmission packet extraction unit 2051 determines whether or not the time information given by the other delay equalization control device 2 is included, and if it is included, if it is not included in the delay control unit 2052 Performs processing for passing to the priority control unit 2054 via the normal transmission queue 2057. The delay control unit 2052 determines whether the time obtained by adding a preset delay time to the time information included in the packet exceeds the current time. If it exceeds the delay control unit 2052, the delay control unit 2052 passes the packet to the priority control unit 2054 via the priority transmission queue 2056. At this time, correction information such as an excess time may be added to the packet. Further, an excess packet may be discarded if transmission is unnecessary. If not exceeded, the delay control unit 2052 pools the corresponding packet in the adjustment buffer 2053 and starts a timer until the time when the packet is exceeded. When the timer expires, the delay control unit 2052 extracts the corresponding packet from the adjustment buffer 2053, and passes the packet to the priority control unit 2054 via the priority transmission queue 2056. The priority control unit 2054 receives packets from the transmission packet extraction unit 2051 and the delay control unit 2052, and performs control processing for preferentially transmitting the packets received from the delay control unit 2052. Although details will be described later, in order to perform strict delay control, the priority control unit 2054 reads the scheduled transmission time and the packet size of the packet in the priority transmission queue 2056 to secure the packet transmission bandwidth. In addition, it also has a function of stopping reading from the normal transmission queue 2057 at that timing.

  FIG. 24 shows an example of the configuration of the priority transmission time management table T60. As shown in the figure, the priority transmission time management table includes a management number T601 for managing an entry, a priority transmission time T602 indicating a (planned) time for transmitting a priority packet, a packet length T603 of the priority packet, and a corresponding entry transmitted. A transmission flag T604 indicating whether the transmission has been completed or not transmitted is included. For example, as will be described later with reference to FIG. 23, the priority transmission time T602 is used to search the transmission time of the priority packet to be transmitted next from the entries. The packet size T603 is auxiliary information for assuming a transmission completion time. The transmission flag T604 is a flag for determining whether the transmission has been completed or not yet transmitted. The registration flag T604 is registered as untransmitted at the time of registration, and is changed to transmitted when the priority control unit 2054 completes transmission.

The user line control interface unit 20 shown in FIGS. 3 and 4 may allocate only one of the user line control interface units 20A or 20B to one apparatus according to the line accommodated by the apparatus. However, when the accommodated lines are mixed, the user line control interfaces 20A and 20B can be assigned to one apparatus. Moreover, it is good also as one user line control interface part which has the function shown in FIG. 3 and FIG.
FIG. 6 shows a specific example of a flowchart for processing a packet received from the user side by the received packet processing unit 202 shown in FIG. The received packet extraction unit 2021 confirms the contents (for example, destination IP address, destination port number, protocol type, etc.) of the packet received at the PHY termination point, as shown in FIG. It is determined whether or not the packet matches the conditions in the time grant packet determination table (S101). In the case of a packet that matches the determination condition of the processing of S101 described above, time stamp information indicating the reception time is given based on the time managed in the apparatus in the time stamp unit 2022 (S102). That is, the time stamp information is not added in the case of a packet that does not match the determination condition in the processing of S101. Thereafter, the received packet is stored in the transmission buffer on the internal switch 30 side (S103). Thereafter, the data is transferred to the network line control interface unit 21 leading to the output destination through the internal switch unit 30 and transmitted to the transmission network 5 from the network line control interface 21.
The specific packet to which the time stamp is given includes, for example, one of IEEE 1588 PTP communication time measurement signal, product or information ordering / request signal in electronic commerce, and real-time streaming signal such as voice communication and broadcasting. Can be included.

FIG. 7 shows a specific example of a flowchart for processing a packet received from the network side by a function included in a range surrounded by a dotted line of the transmission packet processing unit 205 shown in FIG. The transmission packet extraction unit 2051 determines whether or not there is time stamp information in the packet transmitted from the internal switch unit reception buffer (S201). If a time stamp has been added, the delay control unit 2052 reads the time (entering the reception time Tt) when entering the transmission network 5 from the time stamp information given to the packet (S202). Further, the delay control unit 2052 calculates a time (additional delay time D) for delaying the packet in the present apparatus by a calculation method to be described later (S203), and delay equalization control apparatuses 2-1 and 2 on the user side. -2 deletes the time stamp information given to the packet (S204). Next, the delay control unit 2052 calculates the packet length after deleting the time stamp information (S205). The delay control unit 2052 registers the time obtained by adding the value calculated in S203 to the current time in the priority transmission time management table T60 as the priority transmission time T602 of the corresponding packet, and the calculation result in step S205 as the packet size T603. (S206). The delay control unit 2052 determines whether or not the additional delay time obtained in the calculation process of step S203 is greater than 0 (S207). If the additional delay time is greater than 0, the delay control unit 2052 registers a timer until the additional delay time expires (S209), and stores the corresponding packet in the adjustment buffer 2053 (S210). If the priority transmission time management table T60 is already full during the registration process in S206, the transmission flag T604 is overwritten on the entry that has already been transmitted.
When the additional delay time obtained by the calculation process in step S207 in the delay control unit 2052 is 0 or less, the delay control unit 2052 stores the corresponding packet in the priority transmission queue 2056 (S208). In step S208, correction information may be added to an appropriate field such as correctionField and the corresponding packet may be stored in the priority transmission queue 2056, or the corresponding packet may be discarded. For example, when time synchronization PTP is targeted for delay equalization processing, if a packet exceeding the specified delay time is output as it is, there may be a concern about the influence on synchronization accuracy due to packet fluctuations, etc. In this case, a merit by discarding or adding correction information can be considered.
The packet that is determined not to have a time stamp in the process of step S201 described above is stored in the normal transmission queue 2057 by the transmission packet extraction unit 2051 (S211).
The time (additional delay time) D for delaying the aforementioned packet in the present apparatus is calculated by the following equation (1).

D = Tt + Dnet-Tr (1)

At this time, Dnet is a designated delay time that is delayed in the corresponding network set in advance, and Tr is a time in the delay control apparatus that received the packet. In setting Dnet in advance, for example, the maximum delay time assumed in the corresponding network is investigated, and a value obtained by adding an allowable margin time to the value can be set as Dnet. Further, when the calculation result by the expression (1) becomes a value smaller than 0, it is set to 0.

  FIG. 8 shows a specific example of a processing flowchart in the case where a timer indicating that the timing for sending the packet stored in the adjustment buffer 2053 has arrived in the transmission packet processing unit 205 shown in FIG. 4 has expired. The delay control unit 2052 identifies the corresponding packet whose timer has expired, extracts it from the buffer (S251), and stores it in the priority transmission queue 2056 (S252).

  FIG. 23 shows a specific example of a priority transmission control processing flowchart of the priority control unit 2054 in the transmission packet processing unit 205 shown in FIG. The priority control unit 2054 checks whether there is an entry for which the transmission flag T604 has not been transmitted, from the priority transmission time management table T60 described above with reference to FIG. 24 (S701). When there are one or more corresponding entries, the priority control unit 2054 transmits a packet to be transmitted with the next lowest priority from the priority transmission times T602 among the unsent entries. It acquires as time (Tnext) (S702). The priority control unit 2054 calculates the time during which the non-priority packet can be transmitted (Dnon) as a value obtained by subtracting the current time from the scheduled transmission time (Tnext) of the packet to be transmitted with priority next (S703). The priority control unit 2054 determines whether the value calculated in step S703 is greater than 0 (S705). If it is greater than 0, the priority control unit 2054 checks whether there is a packet in the non-priority queue (S706). When there is a packet in the non-priority queue, the priority control unit 2054 determines whether or not the transmission of the packet is completed within the non-priority packet transmission time (Dnon) based on the packet length of the corresponding non-priority packet (S707). . When transmission of the non-priority packet is completed within the transmission time (Dnon), the priority control unit 2054 acquires the packet from the non-priority queue and transmits it to the PHY termination unit 206 (S708), and the first processing step S701. Return to. If there is no packet in the non-priority queue in the determination process in step S706, and if the packet in the non-priority queue cannot be transmitted within the non-priority packet transmission time (Dnon) in the determination process in step S707, priority is given. The control unit 2054 waits until the scheduled transmission time (Tnext) of the next packet to be transmitted with priority (S709). After waiting, the priority control unit 2054 acquires a packet from the priority queue and transmits the packet to the PHY termination unit 206 (S710). The priority control unit 2054 changes the transmission flag T604 in the priority transmission time management table T60 for the transmitted packet to “transmitted” and returns to the top processing step S701. If it is determined in step S705 that the non-priority packet transmission time (Dnon) is 0 or less, the priority control unit 2054 transmits the packet from the priority queue to the packet extraction PHY termination unit 206 (S710). If it is determined in step S701 that no entry for which the transmission flag T604 is not transmitted is registered in the priority transmission time management table T60, the priority control unit 2054 sets the non-priority packet transmission time in advance. The determined maximum value is set (S704). Subsequent processing is similar to that in step S705 and subsequent steps, and a description thereof will be omitted.

FIG. 9 shows an example of a time assignment packet determination table T10 that holds conditions for determining packets to which time stamp information is attached in the delay equalization control devices 2-1 and 2-2 close to the user. . This table is composed of a management number T101 and time assignment packet determination conditions T102 to T105. In this example, a case is shown in which the destination IP address T102, the destination port number T103, the protocol type T104, and the VLAN IDT 105 are included as the time grant packet determination conditions. These conditions are set by the maintenance person from the setting terminal 50 through the device control unit 10, and the conditions are added / updated / deleted when the device control unit sets the user line control interface unit 20. In addition, it is possible to use one or a plurality of conditions among the time-giving packet determination conditions in combination.
The time stamp information needs to be inserted at a position that does not affect the transmission processing of the intermediate nodes 4-A and 4-B. For example, when performing communication using an IP address on the Ethernet (registered trademark), it is assumed that QoS control and transmission processing are performed based on the information of the Ethernet (registered trademark) header and the IP address header.

  FIG. 10 shows an example of a frame structure to which an Ethernet (registered trademark) frame and a time stamp for IP packet communication are added. In this example, time stamp information is added to the end of the header as a unique option field of the IP header. The time stamp information includes type information representing a unique option type, length information of time stamp information, and time information. Instead of this unique option, if there is no plan to use the timestamp option in the network, the original IP option timestamp may be used. This figure shows the case of an Ethernet (registered trademark) frame, but even in the case of an MPLS (Multi Protocol Label Switch) packet, a similar configuration is possible when an IP address is included in the payload of MPLS. When the IP address is not included in the MPLS payload, it can be realized by adding time stamp information between the MPLS header and the MPLS payload.

2-3. Network circuit control interface unit 21
FIG. 5 shows an example of a block diagram of the network circuit control interface unit 21 in the present embodiment. As shown in the figure, the network line control interface unit 21 includes an internal switch unit reception buffer 211 that temporarily holds packets received from the internal switch unit, a packet transfer control unit 212 that performs packet transfer control, a transmission network interface ( Hereinafter, a PHY termination unit 213 that transmits and receives packets to and from the NNI side, a network delay measurement unit 214 that measures network delay time on the NNI side, and a packet distribution control unit 215 that distributes packets received from the NNI side The internal switch unit transmission buffer 216 that temporarily holds packets to be transmitted to the internal switch unit, the user line control IF management unit 217 that manages the network line control interface unit, and the timing synchronization unit 40 for acquiring time information Is an interface Period timing control IF218, between an interface for performing various settings by the device control unit 10 CPU communication IF219, comprising the backup information 21A is a nonvolatile memory for holding the setting data.
The network delay measurement unit 214 in the network line control interface unit 21 includes a measurement packet insertion unit 2141, a delay time calculation unit 2142, and a time management unit 2143 as functional blocks.
These functions are the network between the delay equalization control devices 2-1 and 2-2 installed closer to the user side and the delay equalization control device 2-3 installed closer to the server side. A function to measure the delay time is realized. The time management unit 2143 periodically notifies the measurement packet insertion unit when a specific time comes. In the measurement packet insertion unit 2141, the counter device registered in advance (from the delay control devices 2-1 and 2-2 installed closer to the user side in the example of FIG. 1 closer to the server side). A delay measurement packet carrying the time information managed by the own device is sent out (to the installed delay control device 2-3). The delay time calculation unit 2142 calculates the delay time between the corresponding devices from the current time of the own device in the packet based on the time information included in the delay measurement packet received from the packet distribution control unit 215 and the source IP address. Calculation is performed by subtracting the time of the included time information, and the information is notified to the network line control IF management unit 217.
This function can be set by the maintenance person to stop or use the function from the setting terminal 50 through the device control unit 10. Also, the network delay time measured by this function is collected in the device management unit 10 and used to calculate the delay equalization time for the corresponding network. Instead of the network delay time that can be set through the device control unit 10 from the setting terminal 50 by the maintenance person, the value calculated by this function can be used as the network delay time.
The network line control IF management unit 217 notifies the device management unit 10 via the inter-CPU communication IF 219 of the combination of the transmission source IP address and the delay time information notified from the packet distribution control unit 215.

  FIG. 14 shows an example of the transmission information management table T30 described above. As shown in the figure, the transmission information management table T30 includes an entry management number (T301), a transmission target network name (T302), a transmission packet condition (T303) such as what packet is transmitted, A valid / invalid flag (T304) indicating whether the entry is valid or invalid is included. In this example, the transmission packet condition (T303) includes a destination IP address (T3031), a protocol type (T3032), a VLAN ID (T3033), and an Ethernet (registered trademark) frame length (T3034). The management information is set by the maintenance person from the setting terminal 50 through the device control unit 10, and the conditions are added / updated / deleted when the device control unit sets the network line control interface unit 21. . In addition, it is possible to use one or a plurality of conditions among the transmission packet conditions in combination.

  In FIG. 11, a specific example of a flowchart in which the network delay measuring unit 214 transmits a packet for measuring the network delay time between the delay equalization control device 2-1 or 2-2 and the delay equalization control device 2-3. Is shown. As described above, the process shown in the figure is started upon receiving a notification from the time management unit 2143 periodically. The measurement packet inserting unit 2141 sequentially determines from the top of the transmission information management table T30 of FIG. 14 described above, and determines whether there is a destination to be transmitted from among the destination IP addresses registered in advance (S301). . If there is a destination to be transmitted, the measurement packet insertion unit 2141 further determines whether the corresponding destination IP address is set valid (T304) (S302). When the destination IP address is valid, the measurement packet insertion unit 2141 generates a packet according to the transmission information management table T30 (for example, the transmission packet condition T303) (S303). Further, the measurement packet insertion unit 2141 adds the time managed by the own device in the time stamp information (S304), and stores the packet in the queue for the packet transfer control unit 212 (S305). Thereafter, the measurement packet insertion unit 2141 changes to the next entry in the transmission information management table T30 (S306), and returns to the process of step S301. If it is determined to be invalid in the determination in step S302, the measurement packet inserting unit 2141 does not transmit the delay measurement packet for the corresponding address, changes to the next entry (S306), and returns to the process in step S301. . The measurement packet insertion unit 2141 performs the same processing for other destination addresses, and performs transmission processing until there is no destination to be transmitted. If there are no more addresses to be transmitted in the process of step S301, the process ends.

  FIG. 12 shows a specific example of a flow chart of distribution control when a received packet is sent from the PHY termination unit 213 in the packet distribution control unit 215 of the network line control interface unit 21 (S400). The packet distribution control unit 215 determines whether the destination IP address of the received packet is the IP address of its own device (S401). If the received packet is the own device IP address, the packet distribution control unit 215 determines whether time information is included (S402). If the time information is included, the packet distribution control unit 215 determines that the packet is a delay measurement packet and passes the packet to the network delay measurement unit 214 (S403). If the IP address of the own device is not used in the process of step S401 and if time information is not included in the process of step S402, the packet distribution control unit 215 determines that the packet is other than the delay measurement packet. The corresponding packet is stored in the internal switch transmission buffer (S404).

  FIG. 13 shows a specific example of a flowchart when the network delay measurement unit 214 of the network line control interface unit 21 sends a packet determined to be a delay measurement packet from the packet distribution control unit 215 as described above. (S450). The delay time calculation unit 2142 confirms whether or not the transmission source IP address is included in the list of monitoring target IP addresses registered in advance, and determines whether the opposite device that has transmitted the packet is the monitoring target ( S451). If it is a monitoring target, the delay time calculation unit 2142 acquires time stamp information from the received packet (S452). The delay time calculation unit 2142 determines whether the current time of the own apparatus is newer than the time acquired from the time stamp information sent (S453). When the current time of the own device is newer, the delay time calculating unit 2142 calculates the difference between the time stamp information and the current time of the own device (S454). The delay time calculation unit 2142 notifies the network line control IF management unit 217 of the calculated value and the source IP address information (S455), releases the received packet (S456), and ends the process. If the source IP address is not monitored in the determination in step S451, and if it is determined in step S453 that the time of the time stamp information is newer than the current time of the own device, the delay time The calculation unit 2142 releases the received packet (S456) and ends the process.

2-4. Designated delay time Dnet for the network
Since the device control unit 10 receives the network delay time measurement result and the IP address information of the opposite device from a plurality of network line control interface units, it is necessary to collectively manage the entire device.
FIG. 15 shows an example of the measurement delay time management table T40 managed by the apparatus control unit 10. As shown in the figure, the measurement information management table includes a management number T401 for managing entries, network information for identifying a specific network from a plurality of transmission networks accommodated by the apparatus, and managing the maximum delay time for each network. T402 includes transmission source information T403 for identifying the transmission source and managing information in units of transmission sources. In this example, the network information T402 includes a network name T4021 and a maximum delay time T4022. The transmission source information T403 includes a transmission source IP address T4031, a maximum delay time T4032, and past measurement results (past data) T4033. A specific method of using this table will be described with reference to FIG.

FIG. 16 shows a specific example of a process flowchart in the apparatus control unit 10 when the measurement result of the network delay time calculated by the process flowchart of FIG. 13 and the IP address of the opposite apparatus are sent. The apparatus control unit 10 checks whether or not the corresponding transmission source IP address exists in the measurement delay time management table T40 of FIG. 15 described above, and determines whether it is a management target (S601). If it is a management target, the device control unit 10 deletes old information past the period from the past measurement result (past data) T4033 held for a certain period of the IP address, and is sent this time. The delay time measurement information is updated by adding the added information (S602). The apparatus control unit 10 calculates the maximum delay time measurement information of the corresponding IP address, and updates information on the maximum delay time T4032 for each source IP address (S603). Further, the device control unit 10 calculates the value that is the maximum delay time among the delay times of the network to which the IP address belongs, including the updated information, and updates the maximum delay time T4022 information for each network T402. (S604). The device control unit 10 determines whether the updated maximum delay time T4022 in the network T402 is changed from the previous value before the update (S605). When there is a change, the device control unit 10 calculates a delay time for the corresponding network using Equation (2) described later (S606). The device control unit 10 determines whether the configuration information for the delay equalization device set in advance from the external setting terminal 50 is set to use the value calculated by the delay measurement as the network delay time ( S607). If it is set to be used, the device control unit 10 notifies the user line interface control unit 20 that the corresponding network delay time has been changed (S608), and ends the process. If the source IP address is not managed in step S601, the device control unit 10 ends the process. In addition, when the maximum delay time is the same as the previous value in the process of step S605 and when the setting is not used as the network delay time in the process of step S607, the apparatus control unit 10 The notification is not sent to the user line interface control unit 20, and the process is terminated.
Equation (2) shows an equation for calculating a delay time (designated delay time) Dnet for the network based on the maximum delay time Dmax in the network.

Dnet = Dmax + Deqp + Dmrg (2)

At this time, Deqp is a delay time in the delay device, and Dmrg is a margin time that can be taken for the corresponding network. For Dmrg, for example, it may be determined as 1/10 of Dmax, or may be a value set through the apparatus control unit 10 from the setting terminal 50 by a maintenance person.

3. Sequence FIG. 17 shows a specific example of a schematic sequence between the delay equalization control apparatuses 2 that autonomously measure the network delay time when the present embodiment is applied to the network configuration of FIG. In the figure, the delay equalization control devices 2-1 ("this device A" in the figure) and 2-2 ("this device B" in the figure) close to the user side are automatically processed by the above-described processing of FIG. A packet with time stamp information including time information at the time of transmission in the device is transmitted to the delay equalization control device 2-3 (“present device C” in the figure) close to the server side. Each packet is sent to the delay equalization control device 2-3 ("this device C" in the figure) close to the server side via the intermediate node A4-1 and the intermediate node B4-2 according to the network path in the transmission network 5. To reach. In the delay equalization control device 2-3 (“this device C” in the figure) close to the server side, the delay time with the corresponding opposite device is calculated by the processing of FIGS. 12 and 13 described above. The delay equalization control devices 2-1 (“present device A” in the drawing) and 2-2 (“present device B” in the drawing) close to the user side regularly transmit the aforementioned packets.
FIG. 18 shows a timing chart of an example in which the delay time passing through the transmission network 5 is equalized for a plurality of users when the present embodiment is applied in the network configuration of FIG. In this example, the transmission network 5 is defined as a delay equalization network that equalizes with a delay time Dnet.
In the figure, packets sent from the user A and the user B to the server C are set as delay equalization target packets that match the conditions registered in the time grant packet determination table T10 shown in FIG. When the packet sent from the user A to the server C arrives at the delay equalization control device 2-1 ("this device A" in the figure), the arrival time Ta is given as time stamp information and the intermediate node A4 -1. Thereafter, when being transferred from the intermediate node A 4-1 to the intermediate node B 4-2, fluctuation due to congestion or the like occurs, arrives at the intermediate node B 4-2 later than usual, and is further transferred to the delay equalization control device 2. -3 ("this device C" in the figure) arrives at time Tca. On the other hand, when the packet sent from the user B to the server C arrives at the delay equalization control device 2-2 ("this device B" in the figure), the arrival time Tb is given as time stamp information. Sent to Node B 4-2. Thereafter, it is assumed that the packet is transferred from the intermediate node B4-2 and arrives at the delay equalization control device 2-3 ("present device C" in the figure) at time Tcb. Therefore, in this example, in addition to the normal delay difference that occurs due to the physical network configuration that can be assumed in advance, a difference occurs in the network transit time due to fluctuation delay due to congestion that cannot be understood unless it actually passes through the packet. Will be.
In the delay equalization control device 2-3 (“this device C” in the figure) that receives the packets from the users A and B, the delay time Da and the delay time Da as shown in FIG. Since transmission is performed after Db is calculated and delayed within the apparatus for that time, the packet sent from user A is sent at time Tsa, and the packet sent from user B is sent at time Tsb. As a result, the time difference between the times Ta and Tb when the packets of the users A and B arrive at the delay equalization network and the time difference between the times Tsa and Tsb respectively sent from the delay equalization network are expressed as follows: It is possible to be the same. In other words, the time difference from the time Ta when the packet of the user A arrives at the delay equalization network to the time Tsa sent out and the time difference from the time Tb when the packet of the user B arrives at the delay equalization network to the time Tsb sent out. Can be set to the same Dnet.
Da = Dnet- (Tca-Ta)
Db = Dnet− (Tcb−Tb)
Tsa = Tca + Da = Dnet + Ta
Tsb = Tcb + Db = Dnet + Tb
Tsb-Tsa = Tb-Ta

FIG. 19 is an example of a timing chart showing processing when a packet to be delayed and a best effort packet are sent from the user A in the network configuration of FIG. 1 to which the present embodiment is applied. In this example, as in FIG. 18, the transmission network 5 is defined as a delay equalization network that equalizes with a delay time Dnet.
In this figure, the user A makes two delay equalization target packets (A1 and A3 in the figure) that match the conditions registered in the time grant packet determination table T10 shown in FIG. An example is shown in which a total of four packets (A2 and A4 in the figure) of normal best effort packets that do not match the conditions registered in the granted packet determination table T10 are transmitted. When the delay equalization target packet reaches the delay equalization control device 2-1 ("this device A" in the figure), the arrival times Ta and Tc are given as time stamp information and sent to the intermediate node A4-1. The One best effort packet is sent to the intermediate node A4-1 without being given time information by the delay equalization control device 2-1. Thereafter, the delay equalization control device 2-3 ("this device C" in the figure) arrives at times Tc1, Tc2, Tc3, and Tc4 at the time Tc1, Tc3, and Tc4, respectively, due to the influence of processing congestion of the intermediate node A And
In the delay equalization control device 2-3 ("this device C" in the figure) that has received the packet, the delay equalization target packet including the time stamp information is shown in the same figure according to the above equation (1). As shown in the figure, delay times Da1 and Da3 are calculated, and transmission is performed after delaying within the apparatus by that time. As a result, it passes through the delay equalization network over Dnet as in FIG.
On the other hand, since the time stamp information is not given to the normal best effort packet, the delay equalization control device 2-3 (“this device C” in the figure) does not perform the delay processing and the like. Since the data is transferred to the server C, normal transfer is possible.

C. Second embodiment

In the first embodiment, an example in which the delay target packet passes through the transmission network 5 uniformly at the same time has been shown. However, in this embodiment, the delay equalization control device that can change the time to pass depending on the packet type is shown. An example will be described.
The network configuration example is the same as that in FIG.
The delay equalization control devices 2-1 and 2-2 installed on the side closer to the user are the same as those in the first embodiment with respect to the device configuration and functional blocks, and the processing to be performed, and the description thereof is omitted.
About the delay equalization control apparatus 2-3 installed in the side close | similar to the server side, an apparatus structure and a functional block are the same as Example 1, and description is abbreviate | omitted.

  FIG. 20 shows an example of a delay time management table T20 managed in the delay equalization control apparatus 2-3 installed on the server side in this embodiment. As shown in the figure, the delay time management table T20 includes a management number T201, target packet determination conditions T202 to T205, and a network delay time T206. In this example, the target packet determination conditions are four combinations of the destination IP address T202, the destination port number T203, the protocol type T204, and the VLAN IDT 205, but other conditions can be used as long as the packet can be specified. A combination of one or more conditions may be included. The network delay time T206 indicates a time (designated delay time) Dneti for delaying a packet that matches the target packet determination condition from the time of arrival at the transmission network 5 until the packet is transmitted. The delay time management table T20 is set by the maintenance person through the device control unit 10 from the setting terminal 50, and conditions are added / updated / deleted when the device control unit sets the user line control interface unit 20. Is called.

FIG. 21 shows a specific example of a flowchart for processing a packet received from the network side in the transmission packet processing unit 205 shown in FIG. 4 in the delay equalization control apparatus 2-3 installed on the side close to the server side in this embodiment. Show. The transmission packet extraction unit 2051 determines whether or not there is time stamp information in the packet transmitted from the internal switch unit reception buffer (S501). When the time stamp information is included, it is sent to the delay control unit 2052, and the delay control unit 2052 determines whether or not the target packet determination condition (T202 to T205 in FIG. 20) of the delay time management table T20 is met. A determination is made (S502). If the target packet determination condition is met, the delay control unit 2052 acquires time information in the packet (S503), and acquires the network delay time (designated delay) for the acquired time Tt and the corresponding condition of the delay time management table T20. Time) Dneti (which is T206 in FIG. 20), and a time (additional delay time) Di to be delayed by this apparatus using the time Tr of the corresponding apparatus is calculated. The calculation method is shown in the following formula (3).

Di = Tt + Dneti-Tr (3)

The subsequent steps S505 to S511 are the same as the steps S204 to S210 in FIG. In addition, the processing in the case where there is no time stamp information in the determination in step S501 in the figure is the same as the processing in the case where there is no time stamp information in the determination in step S201 in FIG.
If it is determined in step S502 in the figure that the conditions of the delay time management table T20 are not met, the delay control unit 2052 deletes the time stamp information (S512) and stores it in the normal transmission queue (S513). .
Since the processing sequence (FIGS. 8 and 23) of the transmission packet processing unit 205 other than the above is the same as that of the first embodiment, description thereof is omitted.

FIG. 22 shows an example of a timing chart showing processing when two types (video, audio) of delay equalization target packets are sent from the user A in the network configuration of FIG. 1 to which the present embodiment is applied. In this example, as the transit time of the delay equalization network, the Dmov time having a relatively large value for the delay equalization target packet of video that is one-way communication is the voice delay that is bidirectional communication, etc. It is assumed that the Dsnd time that is relatively close to the transit time is set in advance in the packet to be converted.
In the figure, the user A transmits two video and audio delay equalization target packets to the server C two by two. When the delay equalization target packet of the first video arrives at the delay equalization control device 2-1 ("this device A" in the figure), the arrival time T1 is given as time stamp information, and is sent to the intermediate node A. Sent to. Similarly, the delay equalization control device 2- of the first audio delay equalization target packet is T2, the second audio delay equalization target packet is T3, and the second video delay equalization target packet is T4. 1 ("this device A" in the figure) is given as time stamp information and transmitted to the intermediate node A4-1. In the intermediate node A4-1, priority control for giving priority to transmission of voice packets is set, and congestion has occurred. Therefore, the first voice packet, the second voice packet, the first video packet, It is assumed that the second video packets are sent sequentially in the order. After that, those packets arrive at the delay equalization control device 2-3 ("this device C" in the figure) in the same order via the intermediate node B4-2 at T5, T6, T7, and T8. . The delay equalization control device 2-3 calculates and delays each packet delay time according to the above-described equation (3). At this time, for Dneti in Expression (3), Dsnd is used for the first audio packet and the second audio packet, and Dmov is used for the first video packet and the second video packet. In this way, the packet type is differentiated. Thereafter, the packets after the delay time have passed are sent to the server C in order, the first audio packet at T9, the second audio packet at T10, the first video packet at T11, and the second video packet at Each is sent out at T12. As a result, the voice packet passing through the transmission network 5 is passed to the server side at equal intervals of Dsnd, and the time difference T3 when it arrives at the delay equalization control device 2-1 between voice packets ("this device A" in the figure). -T2 and the time difference T10-T9 sent from the delay equalization control device 2-3 ("this device C" in the figure) are made the same to eliminate fluctuations and transfer in a shorter time than a video packet. It becomes possible to do.

  In the above description, an audio packet is given as an example of a packet with high real-time characteristics, and a video packet is given as an example of a packet with low real-time characteristics. . Two or more packet types may be used. When there are a plurality of packet types, different delay times can be set according to the real-time property of each packet type (for example, the higher the real-time property, the shorter the delay time).

D. Effects of the embodiment

According to this embodiment, in a network using a delay equalization control device, packets that are required to be fair in terms of network delay are not affected by fluctuation due to delay, and pass through the network with the same delay time to the opposite server. It can be sent out. In addition, packets that do not require fairness with respect to delay transmitted by best effort or existing QoS can be communicated without occupying unnecessary bandwidth by being transferred as before.

E. Appendix

In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.
Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.
Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

1: User terminal 2: Delay equalization control device 3: Server 4: Intermediate node router 5: Transmission network 6: Access network

Claims (10)

A communication system,
A first communication device interconnecting the first network or the first device and the transmission network;
A second network or a second communication device interconnecting the second device and the transmission network;

The first communication device is:
When the first specific packet to be subjected to delay control is extracted from the packet received from the first network or the first device, the time when the first specific packet is received is set as the time stamp time in the first specific packet. A receiving packet processing unit for inserting the first packet to the transmission network,

The second communication device is:
A transmission packet extraction unit that extracts the first packet including the time stamp time from a packet received from the transmission network;
A time stamp time is read from the first specific packet extracted by the transmission packet extracting unit, and the time when the first specific packet is received from a predetermined delay time in the transmission network and the time stamp A delay controller for subtracting a time difference from the time to calculate an additional delay time, and holding the first specific packet until the additional delay time elapses;
A priority control unit configured to receive the first specific packet from the delay control unit when the additional delay time has elapsed and to transmit the first specific packet in preference to other packets; Communication system.
The communication system according to claim 1,
The priority control unit secures a band for transmitting the first specific packet after delay adjustment in the delay control unit according to a scheduled transmission time and a packet size of the first specific packet, and more than other packets. A communication system characterized by being preferentially transmitted to an external network or an external device.
The communication system according to claim 1,
The received packet processing unit transmits a packet not corresponding to the first specific packet to the transmission network without inserting the time stamp time.
The communication system according to claim 1,
When the second communication device receives a packet other than the first specific packet extracted in the transmission packet extraction unit from the packets received from the transmission network,
The priority control unit confirms a scheduled transmission time for the first specific packet, extracts a free time zone that is not scheduled to be transmitted for the first specific packet and can be output to an external network or an external device, and A communication system, wherein the other packet is transmitted without giving a specific additional delay in a time zone.
The communication system according to claim 1,
When the packet received from the transmission network is not a packet including the time stamp time, the transmission packet extraction unit stores the packet in a normal transmission queue,
The priority control unit outputs a packet in the normal transmission queue to an external network or an external device.
The communication system according to claim 1,
The delay control unit
If a time stamp time is included in the packet received from the transmission network, the time stamp time is removed,
The packet length after deleting the time stamp time is calculated, the time obtained by adding the additional delay time to the current time is obtained as the priority transmission time of the corresponding packet,
If the additional delay time is greater than 0, register a timer until the additional delay time expires, store the corresponding packet in the adjustment buffer, and take out the corresponding packet for which the timer has expired from the adjustment buffer, Store in the priority processing queue,
On the other hand, when the delay adjustment time is 0 or less, the corresponding packet is stored in the priority transmission queue, or the correction packet is added to store the corresponding packet in the priority transmission queue, or the corresponding packet is discarded. ,
The communication system, wherein the priority control unit outputs a packet in the priority transmission queue to an external network or an external device.
The communication system according to claim 1,
The designated delay time Dnet held by the delay control unit is:
A maximum delay time Dmax in the transmission network,
Delay time Deqp in the communication device, and
A predetermined margin time Dmrg,
A communication system characterized in that the time is obtained by adding together.
The communication system according to claim 1,
The communication apparatus includes a delay time management table storing a specified delay time corresponding to a packet determination condition,
The transmission packet extracting unit refers to the delay time management table and determines the designated delay time based on a packet determination condition of the first specific packet.
The communication system according to claim 1,
The transmission packet extraction unit includes:
When the first specific packet is a packet having a high real-time property, the first value is used as the designated delay time,
A communication system, wherein a second value longer than the first value is used as the designated delay time when the first specific packet is a packet having a low real-time property.
A communication device,
When interconnecting the first network or the first device and the transmission network,
When the first specific packet to be subjected to delay control is extracted from the packet received from the first network or the first device, the time when the first specific packet is received is set as the time stamp time in the first specific packet. A receiving packet processing unit for inserting the first packet to the transmission network,

When interconnecting a second network or a second device and the transmission network,
A transmission packet extraction unit that extracts the first packet including the time stamp time from a packet received from the transmission network;
A time stamp time is read from the first specific packet extracted by the transmission packet extracting unit, and the time when the first specific packet is received from a predetermined delay time in the transmission network and the time stamp A delay controller for subtracting a time difference from the time to calculate an additional delay time, and holding the first specific packet until the additional delay time elapses;
A priority control unit configured to receive the first specific packet from the delay control unit when the additional delay time has elapsed and to transmit the first specific packet in preference to other packets; Communication device.

Images