JPH0548715A - Traffic control system - Google Patents

Abstract

PURPOSE:To prevent a payload to be sent from being increased unnecessarily by interposing a channel filter for sending a payload part from a subscriber side to a pay telephone network between the pay telephone network and an exclusive line only when the presence of traffic data in the payload part from the subscriber side is detected. CONSTITUTION:The label monitor part 42 of a channel filter checks whether the C2 bit of a path overhead POH is '1' or '0' and sends its data frame to a buffer 44. When the detection result shows '1', namely, when the traffic data is present in the payload part, an output control part 43 is informed of that to send its data frame to a multiplexing part 46 and perform counting 45, thereby informing the charging side of the pay telephone network of the counted value. When the detection result shows '0', namely, when the traffic data is not present, the data frame is discarded through the control part 43 and the counter 45 performs no counting operation. Consequently, only the necessary payload is sent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traffic control system, and more particularly to controlling data traffic on a digital leased line between a public telephone network (PUBLIC NETWORK: PN) and a subscriber system (hereinafter, simply referred to as a subscriber). It is related to the method.

When a subscriber accesses data to a public telephone network owned by a telephone company through a digital leased line, leased lines of various bit rates are prepared and used according to the bit rate of each subscriber. It is desirable to be able to.

[0003]

2. Description of the Related Art FIG. 8 schematically shows a digital communication network in which a public telephone network 1 and a subscriber 2 are connected by a digital leased line 3. The conventional leased line 3 is 2.
Although 4Kb / s to 56Kb / s, 1.5Mb / s, 45Mb / s, and other bit rates have been put into practical use, such dedicated bit rates will increase the capacity of subscriber services in the future. Is insufficient for.

Therefore, as a future trend, SONET (Synchronous Optical Net) has already been proposed as a network for coping with the increase in the capacity of such services.
work) optical transmission system is expected to be applied. In this case, a 600 Mbps optical leased line called OC-12 or OC
A 2.4Gbps optical leased line called -48 will be used as a subscriber digital leased line.

[0005]

However, in the above-mentioned leased line bit rate, for example, 1.5 G
When a leased line such as 0C-30 with a bit rate of bps is optimal, but there is no such leased line, the above OC-12 leased line has insufficient bit rate for the subscriber. Since it cannot be used, OC-48's leased line will be used. In this case, when the telephone company provides digital services to the OC-48 for the subscriber, the public telephone network is input from the subscriber side. The transmitted OC-48 digital data must always be transmitted.

However, the line capacity of 2.4 Gbps of OC-48 is a bit rate derived assuming "when the usage amount is maximum", and not all data frames are always used by subscribers. No, there is a case where only the amount of data equivalent to the OC-1 line is used, and when not used (at night, etc.)
However, in the current service form, it is impossible to distinguish between used data frames and unused data frames, so even if traffic data does not exist in the frame, it is unconditionally public. Must be transmitted over the telephone network.

Therefore, in such a state, it is useless for a telephone company that owns a public telephone network to transmit a frame that does not include traffic data in the same manner as a frame that includes traffic data. This is one of the reasons why the usage efficiency cannot be increased.

[0008] Further, there is a problem in that it is useless for the subscriber to pay a 100% charge for a 100% unused line.

Therefore, the present invention realizes a traffic control method which is beneficial to both the telephone company and the subscriber by enabling selection of frames transmitting traffic data and frames not transmitting traffic data. With the goal.

[0010]

In such a communication network, the characteristics of the data frame are utilized in FIG.
As shown in (a), if a predetermined part (hatched) in the frame header H can indicate whether traffic data exists in the payload part, a frame that does not include traffic data in the payload part PL can be detected. The interface with the public telephone network can be automatically discarded, and the above problems can be solved.

Therefore, according to the present invention, as shown in FIG. 2B, the contents of a predetermined bit portion called a signal label in the header portion H of the data frame from the subscriber 2 (see FIG. 5) side is changed according to the contents. It is determined whether or not traffic data is present in the payload portion of the frame, that is, whether or not the payload is used, and the data frame is sent to the public telephone network 1 only when it is detected that it is present.
Otherwise, the channel filter 4A for discarding the data frame is inserted between the public telephone network 1 and the private line 3.

Further, in order to send a data frame from the public telephone network 1 to the subscriber 2, the traffic data always exists in the payload of the data frame flowing through the public telephone network 1. For a channel for which no traffic data exists, the channel restoring unit 4B inserted between the public telephone network 1 and the dedicated line 3 restores the channel and sends it to the dedicated line 3.

In this way, by suppressing the number of payloads flowing into the public telephone network, it is possible to prevent the payload that the public telephone network must transmit from increasing more than necessary, and also to add a system on the subscriber side. Even if there is such a situation, it is not necessary to increase the transmission capacity unnecessarily.

In this case, the channel filter 4A operates as shown in FIG.
As shown in FIG. 4, a separation unit 41 that separates the multiplexed data frame from the subscriber side for each channel, and the separation unit 4
A concentrator 40 for detecting whether or not traffic data exists in the payload part of the channel data separated by 1 and passing only when the presence of the traffic data is detected, and a concentrator for each channel It can be configured with a multiplexing unit 46 that multiplexes traffic data from the unit 40 and sends it to the public telephone network 1.

Further, as shown in FIG. 2, the concentrator 40 is provided with a label monitor 42 which is provided for each channel data separated by the separator 41 and monitors a predetermined bit portion in the header of the data. , This label monitor unit 42
And an output control unit 43 connected to the label monitor unit 43 and the output control unit 43 for detecting whether or not traffic data exists in the payload portion by the predetermined bit portion. Each can be configured by a buffer 44 that allows the channel data output from the label monitor unit 42 to pass to the multiplexing unit 46 only when the presence of the traffic data is detected.

Further, the above-mentioned concentrator 40 has a buffer 44.
May include a payload counter 44 that counts each time traffic data is output and outputs it as billing information to the public telephone network side. In this case, by grasping the quantity of payloads flowing into the public telephone network, the quantity of subscriber services can be quantitatively grasped, and the billing calculation can be made finer.

[0017]

FIG. 2 shows an embodiment of the channel filter 4A and the channel restoration unit 4B shown in FIG. 1 (b). In this embodiment, the channel filter 4A has channels CH # 1 to CH #. The data from each subscriber terminal from Y is multiplexed by the interface unit 10 and the data sent to the subscriber dedicated line 3 is connected to each terminal on the subscriber side. Channels CH # 1 to CH # Y (each channel is STS-Nc frame structure), a separation unit (DMUX) 41, a label monitor unit 42 for detecting a predetermined bit portion in the header portion of each channel data, that is, a label, which is provided for each of these separated channels. An output control unit 43 connected to the label monitor unit 42 for detecting whether traffic data exists in the payload unit by the label and a label monitor 42 and an output control unit 43, which are connected to a buffer 44 and a buffer 44 which allow the channel data output from the label monitor unit 42 to pass to the multiplexing unit 46 only when the output control unit 43 detects the presence of traffic data. Payload counter 4 that counts each time the buffer 44 outputs traffic data
Concentrators 40-1 to 40-Y each composed of 5 and
And each of the buffers 44 of these concentrators 40-1 to 40-Y
And a multiplexing unit (MUX) 46 that multiplexes the data frames from 1 to 3 again between the channels.

Further, the channel restoration unit 4B has a multiplexing unit 47.
When there is no corresponding one of the channels CH # 1 to CH # Y in the data frame from the public telephone network 1, the interface unit 10 restores (multiplexes) the data frame of the channel. To give to.

The data frame shown in FIG. 1 (a) is, for example, as shown in FIG.
One frame can be used, and C in POH (Path-Overhead) in a data frame of 270 bytes x 9 rows
2 bits (1 bit) can be used as a signal label to indicate whether or not traffic data exists in the payload part. It should be noted that this POH is a place for storing the control code between the subscribers 2 as shown in FIG.
A bit is a 1-bit part that is not normally used. Also,
SOH (Section-Overhead) and LOH (Line-Overhead)
Are locations for transmitting control signals between relay stations RL and between telephone companies TC, as shown in FIG.

The operation of the above embodiment will now be described.
In the AN (Local Area Network) or the like, the data frames from the subscriber terminals 2 respectively connected to the channels CH # 1 to CH # Y are converted by the interface unit 10 into one multiplexed data frame, Channel filter 4 via subscriber's dedicated line 3
Sent to A.

In this channel filter 4A, first, the input data frame is separated by the separation unit 41 into each channel CH #.
1-CH # Y are separated, and as shown in FIG. 4, the separating unit 41 sets Lin between the telephone companies TC and between the relay stations RL.
Since e and Section are respectively terminated, LOH and SOH shown in FIG. 3 are detected to check whether each input channel is correct or not, and if not, an alarm signal is generated as shown in the figure. ing.

In the data frame of each channel separated by the separation unit 41, for example, in the channel CH # 1, the C2 bit of POH shown in FIG. 3 by the label monitor unit 42 is "1" or "0". The data frame itself is sent to the buffer 44 without any deformation.

Then, in the label monitor unit 42, C of POH
When it is detected that 2 bits are "1", that is, in FIG.
When it is found that the traffic data exists in the payload part PL shown in, the output control part 43 notifies the output part 43, and the output control part 43 sends the data frame stored in the buffer 44 to the multiplexing part 46 as it is and the payload. By notifying the counter 45 of the existence of the traffic data, the counter 45 performs the counting operation each time.

Therefore, by notifying the count value of the counter 45 to the charge side (telephone company) of the public telephone network, the charge corresponding to this count value will be made.

On the other hand, in the label monitor unit 42, C2 of POH
When it is detected that the bit is "0", that is, when it is found that there is no traffic data, the data frame in the buffer 44 is discarded via the output control unit 43, and the count value of the counter 45 is not counted. To do so.

The payload output from the buffer 44 in this way is multiplexed between channels by the multiplexing unit 46 and sent to the subscriber dedicated line 3. At this time, in the multiplexing unit 46, as shown in FIG. 4, overhead data of Line between telephone companies and Section data between relay stations RL are generated and transmitted.

Further, the data frame coming from the public telephone network 1 through the subscriber line 3 is sent to the interface section 10 after performing a multiplexing operation of inserting the data frame for the insufficient channel, and is separated into each channel CH #. 1-CH
It is output for each #Y and sent to each subscriber terminal.

FIG. 5 shows the optical fiber line OC-48 on the subscriber side.
2 shows an example of concentrating at the concentrator 40 of the channel filter 4A shown in FIG. 2 when the public telephone network side is the optical leased line OC-24, and as shown in FIG. ) Channel data CH # 1 to # 3 from the subscriber terminal separated by 41 are STS-1 each having one time slot of 50 Mbps, and channel data CH
# 3 to # 18 are S with a time slot of 50 Mbps
150 Mbps STS that is composed by combining three TS-1s
It is 3c.

Then, as shown in the figure, the concentrator 40 converts the OC-48 channel data CH # 1 to # 3 into the OC-24 channel data CH # 1 to # 3 as they are, and the OC-48 channel data CH # 1 to # 3. CH # 8 to # 10 are O
C-24 channel data CH # 4 to # 6, and O
Channel data CH # 15 to # 18 of C-48 is OC-
24 channel data CH # 7 to # 10 are concentrated, and among OC-48 channel data of 48 time slots, channel data CH # 4 to # 7 and CH # 11 to # are included.
It is discarded that the channel data has no payload in 14 total 24 time slots (that is, half of the time slots).

Equivalently showing the concentrating example of FIG. 5 from another angle, it becomes as shown in FIG. 6, but as shown in the figure, the OC-48 channel data has a group of 16 time slots. It consists of three, but since only channel data CH # 1 to # 3 are STS-1 data of 50 Mbps, time slots “1”, “17”, and “33”.
And channel data CH # 4, for example.
Channel data CH # 4-1 is time slot "2"
In addition, the channel data CH # 4-2 has time slot “1”.
8 ", and channel data CH # 4-3 is allocated to time slot" 34 ", and channel data C
In the case of H # 16, the channel data CH # 16-1 is assigned to the time slot “14” and the channel data CH # 16− is assigned.
2 is allocated to the time slot “30”, and the channel data CH # 16-3 is allocated to the time slot “46”.

The channel data CH # 4 is CH #
Since no payload exists in any of 4-1 to 4-3, the payload is discarded in the concentrator 40 as shown in FIG. 6, and in the case of the channel data CH # 16, the channel is Data CH # 16-1 is channel data CH # 16- in time slot "6" of OC-24.
2 is allocated to the time slot “14”, and the channel data CH # 16-3 is allocated to the time slot “22”, which are configured as the channel data CH # 8 on the OC-24 channel data.

FIG. 7 is a tabular display of the line examples shown in FIGS. 5 and 6. As described above, the 48 time slots of the OC-48 are lined up in the half 24 time slots. Has been shown.

Incidentally, in the embodiment shown in FIGS.
An example of concentrating from OC-48 to OC-24 is shown, but in this case, it is expected as a public telephone network that only half of the channel data of OC-48 exists at most. Overflow causes a policing violation, but if underflow occurs, the multiplexing unit 4
Similar to the case of 7, an idle slot will be inserted.

[0034]

As described above, according to the traffic control system of the present invention, only when it is detected that traffic data exists in the payload portion of the data frame from the subscriber 2 side, the payload is detected. Since a channel filter that sends the part to the public telephone network is inserted between the public telephone network and the private line, the payload that the public telephone network must transmit is suppressed by suppressing the number of payloads flowing into the public telephone network. It is not necessary to increase it more than necessary, and it is not necessary to increase transmission capacity unnecessarily even when the subscriber side adds a system.

When the channel filter detects the presence of the traffic data and counts each time and outputs it as billing information to the public telephone network side, in the conventional case, for example, the OC-48 line is used. On the other hand, it was inevitable that the line usage charge would be 1 million yen / month, but the basic line usage charge was 100,000 yen / month, 100 yen / payload. Will be possible. In addition, it is possible to set a rate of "50 yen / payload" as a night discount for nights when the usage is low. This is useful for subscribers who perform computer badge processing and the like at night.

[Brief description of drawings]

FIG. 1 is a block diagram conceptually showing a traffic control system according to the present invention.

FIG. 2 is a block diagram showing an embodiment of a traffic control system according to the present invention.

FIG. 3 is an STM-in SONET used in the present invention.
It is a format diagram of one frame.

FIG. 4 is a block diagram illustrating an overhead part of the STM frame shown in FIG.

FIG. 5 is a concentrating example of a concentrating portion according to the present invention (OC-48 / O).
It is a figure showing C-24).

FIG. 6 is a diagram for explaining the embodiment of FIG. 5 from another angle.

FIG. 7 is a table diagram for explaining the embodiment of FIGS. 5 and 6 from still another angle.

FIG. 8 is a diagram for generally explaining a digital communication network.

[Explanation of symbols]

 1 Public telephone network 2 Subscriber 3 Subscriber leased line 4A Channel filter 4B Channel restoration unit H Header part In the figure, the same symbols indicate the same or corresponding parts.

Claims (4)

[Claims] 1. In a traffic control system for communication in which a public telephone network (1) and a subscriber (2) are connected by a subscriber leased line (3), a header of a data frame from the subscriber (2) side. A channel filter (4) that sends the frame to the public telephone network (1) only when the presence of traffic data in the payload part of the frame is detected from a predetermined bit part in the part
A), and a channel restoration unit (4B) for restoring the data frame of the channel missing in the data frame from the public telephone network (1) and transmitting it to the leased line (3), respectively. A traffic control system characterized by being inserted between the network (1) and the dedicated line (3). 2. The subscriber is provided with the channel filter (4A).
(2) Separation unit (41) for separating the multiplexed data frame from the side for each channel, and whether or not traffic data exists in the payload part of the channel data separated by the separation unit (41) And a traffic concentrator that passes only when the presence of the traffic data is detected (4
0), and a multiplexing unit (46) for multiplexing traffic data from the concentrator (40) for each channel and sending it to the public telephone network (1).
The traffic control system according to claim 1, characterized in that 3. A label monitor section (42) provided with the concentrating section (40) for each channel data separated by the separating section (41) and monitoring a predetermined bit section in a header section of the data.
An output control unit (43) connected to the label monitor unit (42) for detecting whether or not traffic data exists in the payload unit by the predetermined bit portion, the label monitor unit (43) and The channel data output from the label monitor unit (42) is connected to the output control unit (43) and passes to the multiplexing unit (46) only when the output control unit (43) detects the presence of the traffic data. The traffic control system according to claim 2, wherein each of the buffers (44) comprises a buffer (44). 4. A payload counter (45) which the concentrator (40) counts each time the buffer (44) outputs traffic data and outputs it as billing information to the public telephone network side.
The traffic control system according to claim 3, further comprising: