JP2002223245A - Packet communication method and its system and relay start node device and relay starting method and relay node device and relay method and relay end node device and relay ending method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To overcome the problem that during wide band relay communication in a giga-bit Ethernet(registered trademark) communication system, when a received clock is reproduced by a slave relay node, and relay transmission is operated, the relay quality is deteriorated due to the deterioration of the clock, and the number of steps of relay and the distance are limited. SOLUTION: A relay node is provided with a clock generating source, and an independent synchronizing system using each independent clock is realized. The relay node is also provided with an FIFO buffer, and a received signal is inputted to the FIFO buffer, and the output is transmitted by an independent clock. When the capacity of the FIFO buffer exceeds an upper limit Smax or falls below a lower limit Smin, this is adjusted by discarding or inserting an idle code set.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a packet communication system for communicating packets and performing multi-stage relaying. In particular, the present invention performs auto negotiation and adjusts a bit rate difference between a received signal and a transmitted signal at a relay node. Therefore, the present invention relates to a packet communication system for inserting and removing an idle code set.

[0002]

2. Description of the Related Art In order to facilitate understanding of the present invention, an example of a packet communication system to which a conventional packet communication system is applied will be described. FIG. 40 shows a conventional packet communication system.
It comprises a transmitting end node, M subordinate synchronous relay nodes, and a receiving end node. A conventional communication system takes one of a packet communication state and an auto-negotiation communication state. In the packet communication state shown in FIG. 41, an inter-packet signal including a packet and an idle code set between the packet and the next packet transmitted from the transmitting end node is relayed through the M subordinate synchronous relay nodes and received. Communicate to end nodes. In the auto-negotiation communication state, a continuously repeated auto-negotiation communication code set transmitted from the transmitting end node is
It relays the M subordinate synchronous relay nodes and communicates with the receiving end node. The auto-negotiation communication state is a communication state for setting a communication method and the like between the transmitting end node and the receiving end node. At the start of communication, the mobile terminal is in an auto-negotiation communication state, and transitions to a packet communication state when setting of a communication method and the like is completed.

FIG. 42 shows that each subordinate synchronous relay node
This shows a state in which a receiving section reproduces a reception clock from a reception signal and a transmission section transmits the reception signal directly downstream in synchronization with the reception clock.

[0004]

Therefore, in the packet communication system according to the prior art, since the subordinate synchronous relay node regenerates the received clock and transmits using the recovered clock, it occurs at the subordinate synchronous relay node. Clock quality degradation accumulates with each repeat.
For this reason, in the communication system according to the related art, the number of relay stages and the distance are restricted, and a packet communication system over a wide area cannot be constructed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a relay node having a clock generation source instead of a subordinate synchronization system in which the clock quality deteriorates for each relay. An object of the present invention is to provide a packet communication system which can realize a large-scale packet communication system employing an independent synchronization system for transmitting using the clock.

[0006]

According to the present invention, a relay node is provided with a FIFO.
It has a buffer and a transmission clock generation source, and
Input to the FO buffer, and the output of the FIFO buffer is synchronized with the transmission clock output from the transmission clock generation source,
Send.

When the packet communication system is in the packet communication state, the amount of accumulation in the FIFO buffer at the relay node does not exceed the upper limit of the FIFO buffer due to the frequency difference between the reception clock and the transmission clock. The idle code set is inserted / extracted so as not to fall below the threshold. That is, the relay node
When the accumulated amount of the FO buffer exceeds the maximum capacity _Smax ,
Discard the idle code set included in the received signal. F
When the accumulation amount of the IFO buffer is smaller than the minimum capacity S _min , the idle code set is inserted immediately before or immediately after the idle code set included in the received signal.

When the packet communication system is in an auto-negotiation communication state, the amount of accumulation in the FIFO buffer is determined by the difference in frequency between the reception clock and the transmission clock.
The auto-negotiation code set is inserted and removed so that the FO buffer does not exceed the upper limit (overflow) or fall below the lower limit (underflow). That is, when the accumulation amount of the FIFO buffer exceeds _Smax , the relay node discards the auto-negotiation code set included in the received signal. FIFO buffer accumulation amount is S
If the value is less than _min , an auto-negotiation code set is inserted immediately before or immediately after the auto-negotiation code set included in the received signal.

[0009] Alternatively, at a relay start node that relays a signal from a transmitting end node first, an idle code set is inserted between a part or all of the auto negotiation code set and the next auto negotiation code set; Alternatively, a part of the auto negotiation code set is replaced with an idle code set. In the relay nodes subsequent to the relay start node, the accumulation amount of the FIFO buffer exceeds the upper limit of the FIFO buffer due to the frequency difference between the reception clock and the transmission clock (overflow).
The idle code set is inserted and removed so that the value does not fall below the lower limit (underflow). The relay end node transmitting the signal to the receiving end node discards the idle code set sandwiched between the auto negotiation code sets.

In the packet communication system to which the packet communication system of the present invention is applied, the relay node does not transmit using the received clock recovered from the received signal, but the relay node has a transmission clock generation source, Therefore, the deterioration of the clock quality that occurs when the received clock is reproduced from the received signal does not propagate to the next relay node. In the past, the number of relay stages and the relay distance were restricted so that deterioration of accumulated clock quality did not become a problem.
By applying the present invention, the number of relay stages and the relay distance are greatly reduced. Furthermore, in the reproduction of the received clock from the received signal, the allowable value for the clock quality deterioration becomes large, and an inexpensive clock recovery circuit can be applied.

In the auto-negotiation communication state, an idle code set necessary for adjusting the frequency difference between the reception clock and the transmission clock is not transmitted. For this reason,
In the conventional packet communication method, when the independent synchronization method in the relay node is adopted, the frequency difference between the reception clock and the transmission clock cannot be adjusted in the auto-negotiation communication state, so that the FIFO buffer overflows or underflows. there were. By applying the present invention, in both the auto-negotiation communication state and the packet communication state,
It is possible to realize an independent synchronization method.

Further, by replacing the idle code set with a maintenance monitoring information code set obtained by encoding the maintenance monitoring information, communication of the maintenance monitoring information between the relay nodes is possible. In the negotiation communication state, similarly to the packet communication state, communication of the maintenance monitoring information becomes possible.

Further, in the packet communication system to which the present invention is applied, when in the auto-negotiation communication state,
The signal received by the receiving end node is the same as the signal in the conventional auto negotiation communication state in which the idle code set sandwiched between the auto negotiation code sets is removed. Therefore, there is no need to change the receiving end node when applying the present invention.

[0014]

Embodiment 1 Embodiment 1 is an example of a packet communication system to which the inventions of claims 1 and 2 are applied. FIG. 1 shows a packet communication system of the present invention. It is composed of a transmitting end node, M (M is an integer of 1 or more) relay nodes Rep-1 to Rep-M, and a receiving end node.

FIG. 2 shows a signal format transmitted by the transmitting end node in the first embodiment. In FIG. 2, the signal format of the transmitting end takes one of a packet communication state and an auto-negotiation communication state. In the packet communication state, an inter-packet signal including a packet and at least one idle code set between the packet and the next bucket transmitted from the transmitting end node is relayed through the M relay nodes and received. Communicate to end nodes. In the auto-negotiation communication state, a continuously repeated auto-negotiation code set transmitted from the transmitting end node is communicated to the receiving end node via the M relay nodes.

FIG. 3 is a diagram showing a block configuration of the relay node Rep-i according to the first embodiment. In the drawing, a thick arrow indicates a flow of a main signal. In the drawing, thin arrows indicate flows of the reception clock and the transmission clock. The indication of this arrow applies equally to each figure in this specification. The blocks denoted by reference numerals in the figure indicate the following. Reference Signs List 100 receiving unit 102 destuffing unit 104 FIFO buffer 106 stuffing unit 108 transmitting unit 110 transmission clock generation source

The operation of each of these units is as follows. Destuff section (102) (1) An idle code set is detected from the main signal. When a destuff request = True and an idle code set are detected, write enable = False during the period of outputting the detected code set. (2) Detect an AN (auto negotiation) code set from the main signal. When the destuff request = True and the AN code set is detected, write enable = False during the period of outputting the detected code set. FIFO buffer (104) (1) When write enable = True, the main signal input in synchronization with the reception clock is written into the buffer. When write enable = False, writing to the buffer is stopped. (2) When read enable = True, read and output in the order of input to the main signal from the buffer in synchronization with the transmission clock. When the read enable = False, the read is stopped. (3) When the accumulated amount exceeds _Smax , a _destuff request = True is output. When the accumulated amount is smaller than S _min , a staff request = True is output. Stuff unit (106) (1) An idle code set is detected from the main signal. When the stuff request = True and the idle code set is detected, the idle code set is inserted immediately after the detected code set. During the insertion period, read enable = False
And (2) An AN code set is detected from the main signal. When the stuff request = True and the AN code set is detected, the AN code set is inserted immediately after the detected code set. During the insertion period, the read enable is set to False. (In the present specification, AN is an abbreviation for auto negotiation.) That is, as shown in FIG. 3, at least one relay node Rep-i operates in a FIFO
It has a buffer and a transmission clock generation source, and
Input to the FO buffer, and the output of the FIFO buffer is synchronized with the transmission clock output from the transmission clock generation source,
Send.

FIG. 4 is a flowchart showing the operation of the relay node Rep-i according to the first embodiment. FIG. 5 is a time chart showing the positional relationship of each signal at the time of stuff / destuff in the first embodiment. The outline of the flowchart of FIG. 4 is as follows. In the initialization, when S _min ≤ accumulation amount ≤ S _max destuff request = False stuff request = False Write enable = True Read enable = True, FIFO buffer: when the accumulation amount of FIFO <S _min is detected, the accumulation amount <S _min Destuff request = False Staff request = True Write enable = True Read enable = True Stuff part: Input signal = AN code set is detected and AN code set is inserted Destuff request = False Staff request = True Write enable = True Stuff part: AN code set is inserted immediately after the detected code set Stuff part: Insertion period Medium, read enable = False FIFO buffer: output stopped during insertion period, stuff: S _min ≤ accumulation amount ≤ S _{max at} end of AN code set insertion. In addition, stuff part: input signal = idle code set is detected, idle code set is inserted. Destuff request = False stuff request = True, write enable = True stuff part: idle code set is inserted immediately after the detected code set. during the read enable = False FIFO buffer: in during insertion period output stop, staff unit: S _min ≦ insert end of the idle code set
It is assumed that the accumulation amount ≦ _Smax . On the other hand, FIFO buffer: FI
When detecting the FO accumulation amount> _Smax , the accumulation amount <S _min Destuff request = True Stuff request = False Write enable = True Read enable = True, and destuff portion: input signal = AN code set to detect AN code Set discard Destuff request = True Stuff request = True Read enable = True Destuff part: Write enable = False FIFO buffer: Stop input during discard period during output period of detected code set. Destuff section: When the AN code set is discarded, S _min ≦
Accumulation ≦ S _max, and the addition, the destuffing unit: input signal = idle code set the idle code set by the detection discarded destuffing request = True stuff request = True read enable = True destuffing unit: Output period code set has been detected Medium, write enable = False FIFO buffer: input stopped during discard period, destuff section: When discard of idle code set, S
Return to _min ≦ accumulated amount ≦ S _max . It should be understood that the operation of each flowchart will be described in substantially the same manner.

The operation of each relay node Rep-i is further summarized as follows. As shown in FIG. 4 and FIG.
When the accumulated amount of the O buffer exceeds the maximum storage capacity S _max ,
If the received signal includes an idle code set, the idle code set is discarded. When the received signal includes an auto-negotiation code set (AN), the auto-negotiation code set is discarded. FI
If the accumulated amount of the FO buffer is less than the minimum storage capacity S _min and the received signal includes an idle code set,
Immediately after that, an idle code set is inserted. When the received signal contains the auto-negotiation code set,
Immediately after that, an auto negotiation code set is inserted.

The relay node Rep-i performs transmission in synchronization with the transmission clock independent of the reception clock reproduced from the reception signal.
Clock quality deterioration accumulated upstream of i is not propagated. In the packet communication state, since the adjustment of the FIFO buffer storage amount is performed by inserting and removing the idle code set, the packet transmitted from the transmitting end node is communicated to the receiving end node without change. In the auto-negotiation communication state, the adjustment of the FIFO buffer accumulation amount is performed by inserting and removing an auto-negotiation code set.
At this time, since auto-negotiation code sets having the same value are continuous, even if some auto-negotiation code sets are inserted or removed, no problem occurs in communication.

It is to be noted that not all the relay nodes are of the independent synchronous type (a system in which a clock is switched to replace a reception clock with a transmission clock), but are combined with a conventional subordinate synchronous type relay node, so that clock quality is greatly deteriorated. Only in this case, it is possible to use an independent synchronous relay node.

Embodiment 2 Embodiment 2 is an example of a packet communication system in which a relay start node and a relay end node are provided before and after a series of relay nodes. As shown in FIG. 6, the packet communication system of this embodiment includes a transmitting end node, a relay start node, and M (M is an integer of 1 or more) relay nodes as Rep-1 to Rep-M.
, A relay end node, and a receiving end node.

FIG. 7 is a diagram showing a signal format transmitted by the transmitting end node in the packet communication system of the embodiment.
That is, the packet communication system takes a state between a packet communication state and an auto-negotiation communication state. In the packet communication state, at least one idle code set transmitted between the packet and the next packet transmitted from the transmission end node is relayed to the relay start node, the M relay nodes, and the relay end node. ,
Communicate to the receiving end node. In the auto-negotiation communication state, a continuously repeated auto-negotiation code set transmitted from the transmitting end node is communicated to the receiving end node by relaying the relay start node, the M relay nodes, and the relay end node. .

FIG. 8 shows the block configuration of the relay start node according to this embodiment. That is, the relay start node includes:
It comprises an idle code set insertion unit, a clock change unit, and a transmission unit.

FIG. 9 shows the block configuration of the idle code set insertion unit of the relay start node according to the second embodiment, and the bold arrows show the flow of the main signal. The present idle code set insertion section shown in FIG. 9 has the following components, and has the following functions.

Destuff section (200) Detects an AN code set from the main signal. Destuff request
= True and the AN code set is detected,
During the period of outputting the known code set, the write enable =
False. FIFO buffer (202) When write enable = True, the input main signal is buffered.
Write to the web. When write enable = False,
Stop writing to the buffer. Read enable = True
When, read the main signal from the buffer in the order of input
Output. When read enable = False, read
And then stop. Accumulated amount is R_minIf this is the case,
Request = True is output. Accumulated amount is R_maxIn the above cases,
Outputs staff request = False. R_min: Standard number of bits stored in FIFO buffer + AN sign
Number of bits per signal set R_max: The best way to guarantee the normal operation of the FIFO buffer
Large number of accumulated bits (R _minThe stuff section (204) detects an AN code set from the main signal. Staff request =
True and the idle code set insertion timer is
Indicates the passage of time Ti and detects the AN code set
The idle code set immediately after the detected code set.
Insert one. During the insertion period, read enable = Fa
lse. After insertion, idle code set insertion timer
Reset.

FIG. 10 is a flowchart showing the operation of the idle code set insertion unit of the relay start node according to the second embodiment.

FIG. 11 is a table showing the operation of the relay start node / idle code set insertion unit according to the second embodiment. FIG. 9-
The operation of the second embodiment shown in FIG. 11 is summarized as follows. In the idle code set inserting unit, one idle code set is inserted between the auto-negotiation code sets in the idle code set inserting unit at a period Ti.
The idle code set insertion unit has a FIFO buffer and temporarily stores a signal in the FIFO buffer. Insertion of the idle code set increases the accumulation amount of the FIFO buffer. F
When the IFO buffer has accumulated more than the number of bits of the auto negotiation code set, the accumulation amount of the FIFO buffer is adjusted by discarding the auto negotiation code set. The clock changing unit changes a signal synchronized with the reception clock into a signal synchronized with the transmission clock. The transmitting unit transmits the signal output by the clock changing unit to a downstream relay node.

FIG. 12 is a diagram showing a block configuration of a clock switching unit according to the second embodiment. Each component in FIG. 12 has the following functions.

Destuffing diagram (210) An idle code set is detected from the main signal. Destuff request = True and when an idle code set is detected, write enable =
False. FIFO buffer (212) When write enable = True, the main signal input in synchronization with the reception clock is written into the buffer. When write enable = False, writing to the buffer is stopped. When read enable = True, the main signals are read from the buffer in the order of input and output in synchronization with the transmission clock. When the read enable = False, the read is stopped. If the accumulated amount exceeds _Smax , a _destuff request = True is output. When the accumulated amount falls below S _min , the stuff request = True is output. Stuff unit (214) Detects an idle code set or an AN code set from the main signal. When stuff request = True and an idle code set or AN code set is detected, an idle code set is inserted immediately after the detected code set. During the insertion period, the read enable is set to False. A transmission clock is supplied to the FIFO buffer from a transmission clock generation source (216).

FIG. 13 is a flowchart showing the operation of the clock switching unit according to the second embodiment of the present invention.

FIG. 14 is a time chart showing signals at the time of stuff / destuff in the second embodiment. The description of FIGS. 12 to 14 is summarized as follows. The clock change unit of the relay start node has a FIFO buffer and a transmission clock generation source, inputs a signal to the FIFO buffer,
The output of the buffer is transmitted in synchronization with the transmission clock output from the transmission clock generation source. When the accumulation amount of the FIFO buffer exceeds _Smax , if the signal includes an idle code set, the idle code set is discarded. When the accumulation amount of the FIFO buffer falls below S _min and the signal includes an idle code set, the idle code set is inserted immediately after the signal.

FIG. 15 is a diagram showing a block configuration of the relay node Rep-i according to the second embodiment. The relay node Rep-i includes a receiving unit, a clock switching unit, and a transmitting unit. The signal is received by the receiving unit and output to the clock changing unit. The clock changing unit changes a signal synchronized with the reception clock into a signal synchronized with the transmission clock. The transmitting unit transmits the signal output by the clock changing unit to a downstream relay node.

The clock change unit of the relay node Rep-i is the same as the clock change unit of the relay start node, has a FIFO buffer and a transmission clock generation source, inputs a signal to the FIFO buffer, and outputs the signal to the FIFO buffer. Is transmitted in synchronization with the transmission clock output from the transmission clock generation source. When the accumulation amount of the FIFO buffer exceeds _Smax ,
If the signal includes an idle code set, the idle code set is discarded. When the accumulation amount of the FIFO buffer falls below S _min and the signal includes an idle code set, the idle code set is inserted immediately after the signal.

FIG. 16 shows a block configuration of the relay end node according to the second embodiment. The relay end node includes a receiving unit, a clock switching unit, an idle code set discarding unit, and a transmitting unit. The signal received by the receiving unit is output to the clock changing unit. The clock changing unit changes a signal synchronized with the reception clock into a signal synchronized with the transmission clock.

FIG. 17 is a diagram showing a block configuration of the idle code set discarding unit of the relay end node according to the second embodiment.

The idle code set discarding unit comprises a destuff unit (240), a FIFO buffer (242), and a stuff unit (244). The functions of these units are as follows.

Destuff Diagram (240) An idle code set following an AN code set is detected from the main signal. When the destuff request = True and an idle code set following the AN code set is detected, the write enable =
False. FIFO buffer (242) When write enable = True, the input main signal is written into the buffer. When write enable = False, writing to the buffer is stopped. Read enable = True
At this time, the main signals are read out from the buffer in the order of input and output. When the read enable = False, the read is stopped. When the accumulation amount falls below T _min outputs the destuffing request = False. When the accumulated amount falls below _Tmax , a stuff request = True is output. T _max : standard number of stored bits in FIFO buffer−number of bits in AN code set T _min : minimum number of stored bits (value smaller than T _max ) for guaranteeing normal operation of FIFO buffer Stuff section (244) From main signal Detect AN code set. Staff request =
If True and an AN code set is detected, one AN code set is inserted immediately after the detected code set. During the insertion period, the read enable is set to False.

FIG. 18 is a flowchart showing the operation of the idle code set discarding unit of the relay end node according to the second embodiment.

FIG. 19 is a time chart showing the operation of the idle code set discarding unit of the relay end node according to the second embodiment.

The idle code set discarding unit shown in FIGS. 17 to 19 discards the idle code set inserted between the auto negotiation code sets. The idle code set discarding unit has a FIFO buffer, and temporarily stores a signal in the FIFO buffer. By inserting an idle code set, F
The amount of accumulation in the IFO buffer is reduced. When the accumulation amount of the FIFO buffer is reduced to the number of bits of the auto negotiation code set or more, the accumulation amount of the FIFO buffer is adjusted by inserting the auto negotiation code set. The transmitting unit transmits the signal output by the idle code set discarding unit to the receiving end node.

The clock change unit of the relay end node is the same as the clock change unit of the relay start node, has a FIFO buffer and a transmission clock generation source, inputs a signal to the FIFO buffer, and outputs an output of the FIFO buffer. Transmission is performed in synchronization with the transmission clock output from the transmission clock generation source. When the accumulation amount of the FIFO buffer exceeds _Smax ,
If the signal includes an idle code set, the idle code set is discarded. When the accumulation amount of the FIFO buffer falls below S _min and the signal includes an idle code set, the idle code set is inserted immediately after the signal.

As described above, according to the present invention, in the gigabit Ethernet communication system, the relay of the independent synchronization method can be performed. Also, since the relay start node inserts the idle code set in the auto-negotiation communication state, each relay node does not need to insert and remove the auto-negotiation code set in the auto-negotiation communication state, and has the same function as the packet communication state. The process (insertion / extraction of an idle code set) enables clock replacement. Thereby, the relay node is simplified as compared with the first embodiment. In addition, since the relay end node removes all the idle code sets inserted in the auto-negotiation communication state and returns to the original signal in the auto-negotiation communication state, a failure due to a mismatch in the signal format at the receiving end node is prevented.

At the relay start node, some auto negotiation code sets are discarded in order to prevent the bit rate of the transmission signal from being increased by inserting an idle code set in the auto negotiation communication state. However, in the section from the relay start node to the relay end node, if an increase in the bit rate of the signal to be communicated is permitted, the relay start node does not need to discard the auto negotiation code set in the auto negotiation communication state. is there. Also, all nodes from the relay start node to the relay end node are not made to be independent synchronous type, but are combined with the conventional subordinate synchronous type relay node, and are made independent synchronous type relay nodes only when clock quality is greatly deteriorated. It is also possible.

Embodiment 3 Embodiment 3 is an example of application to Gigabit Ethernet. FIG. 20 shows an example of a Gigabit Ethernet communication system to which the present invention is applied. The Gigabit Ethernet communication system of the embodiment shown in FIG.
Relay start node and M (M is 1 or more) relay nodes Re
p1 to Rep-M, a relay node, and a receiving end node.

The gigabit Ethernet communication system shown in FIG. 21 takes one of a packet communication state and an auto-negotiation communication state. In the packet communication state, an Ethernet frame and at least one idle code set between the Ethernet frame and the next Ethernet frame transmitted from the transmitting end node are transmitted to the relay start node, the M relay nodes, and the relay end. Relays the node and communicates to the receiving node. In the auto-negotiation communication state, a continuously repeated auto-negotiation code set transmitted from the transmitting end node is communicated to the receiving end node by relaying the relay start node, the M relay nodes, and the relay end node. .

FIG. 21 is a diagram showing a signal format transmitted by the transmitting end node in the gigabit Ethernet communication system according to the third embodiment. The figure shows a state in which there is an auto-negotiation (AN) communication state at first, followed by a packet communication state. An example of an auto negotiation (AN) code set is /-K28.5+
/D21.5/A1/B1/K28.5/D2.2/A2/B2/+K28.5-/D21.5/A3/B3/
Partly repeated code such as K28.5 / D2.2 / A4 / B4 /. The idle code set is /-K28.5+/+D16.2-/ /-K28.5+/: 0011111010 /+K28.5-/: 1100000101 /D21.5/: 1010101010 /D2.2/: 1011010101 Or 0100100101 / A1 /, / A2 /, A3 /, A4 /, B1 /, / B2 /, B3 /, B4 / are 10-bit data codes, and in combination of these, / + D16.
2- /: A value like 1001000101.

FIG. 22 is a diagram showing a block configuration of the relay start node according to the third embodiment. The relay start node in FIG.
Receiving section, communication state determining section, idle code set inserting section,
It is composed of a relay processing unit and a transmission unit. The reception state determination unit determines whether the signal received by the reception unit is in the packet communication state or the auto-negotiation communication state.

FIG. 23 is a flowchart showing the operation of the communication state determination unit of the relay node according to the third embodiment.

FIG. 24 is a time chart showing the operation of the idle code set insertion unit of the relay start node according to the third embodiment.

As shown in FIGS. 23 and 24, when the auto bit negotiation code set is detected within the period Ta from the previous detection of the auto negotiation code set, it is determined that the communication state is the auto negotiation communication state. If the condition is not satisfied, it is determined that the packet communication state is established. When it is determined that the communication state is the auto negotiation communication state, the idle code set insertion unit replaces the auto negotiation code set with eight idle code sets at a period Ti. The main signal input in the auto-negotiation communication state has an AN code set. The AN code is, for example, /-K28.5+/D21.5/A1/B1 / ...
/-K28.5+/D21.5/A2/B2 / ..., followed by /-K28.5+/D21.5/A
A 'code sets of the same pattern are continuously formed with the same pattern at a period Ti such that 1' / B1 '/ ... is followed by /-K28.5+/D21.5/A2'/B2' / ... Detected (/ Ai / = / Ai '/ and / Bi / = / Bi' /), 2
The eighth AN code set is replaced with eight idle code sets. The output main signal is /-K28.5+/D21.5/A1/B1
/ ... The relay processing unit changes a signal synchronized with the reception clock into a signal synchronized with the transmission clock, and replaces a part of the idle code set with a maintenance monitoring information code set obtained by encoding the maintenance monitoring information. The transmitting unit transmits the signal output by the relay processing unit to a downstream relay node.

FIG. 25 shows a block configuration of the relay processing unit of the relay node according to the third embodiment. The relay processing unit of the relay node in FIG. 25 includes a clock change unit (302), a maintenance monitoring unit information transmission unit (304), and a maintenance monitoring unit (306). The maintenance monitoring unit (306) has the following maintenance monitoring function.・ By communicating parity as maintenance monitoring information,
Monitor the bit error rate. -Monitor erroneous connection by communicating trace information as maintenance monitoring information. -Route switching at the time of failure is performed by communicating the route switching information as maintenance monitoring information.

FIG. 26 is a block diagram showing the clock switching unit (3) of the third embodiment.
02) is a block diagram showing a block configuration of FIG. The clock reordering unit (302) has a FIFO buffer (320) and a transmission clock generation source (322).
The data is input to the buffer, and the output of the FIFO buffer is transmitted in synchronization with the transmission clock output from the transmission clock generation source. When the accumulation amount of the FIFO buffer exceeds _Smax , if the signal includes an idle code set, the idle code set is discarded. When the accumulation amount of the FIFO buffer falls below S _min and the signal includes an idle code set, the idle code set is inserted immediately after the signal.

The details of the operation are as follows. Destuff section (310): detects an idle code set from the main signal. When a destuff request = True and an idle code set are detected, write enable = False during the period of outputting the detected code set. FIFO buffer (320): When write enable = True, writes the main signal input in synchronization with the reception clock to the buffer. When write enable = False, writing to the buffer is stopped. Read enable = True
At this time, the main signals are read out and output from the buffer in the order of input in synchronization with the transmission clock. Read enable =
If False, stop reading. When the accumulated amount exceeds _Smax , a _destuff request = True is output. When the accumulated amount is smaller than S _min , a staff request = True is output. Stuff section (324): detects an idle code set from the main signal. When the stuff request = True and the idle code set is detected, the idle code set is inserted immediately after the detected code set. During the insertion period, the read enable is set to False.

FIG. 27 is a block diagram showing the clock switching unit (3) of the third embodiment.
It is a flowchart which shows operation | movement of 02).

FIG. 28 is a diagram showing the time relationship of each signal at the time of stuff / destuff in the third embodiment.

FIG. 29 is a diagram showing a block configuration of the maintenance monitoring information transmitting unit according to the third embodiment.

FIG. 30 is a diagram showing the operation of the maintenance monitoring information transmitting section (306) of the third embodiment.

The operation is summarized as follows. The maintenance monitoring information transmission unit (306) has a maintenance monitoring information encoding unit and an idle code set replacement unit. The maintenance monitoring information output by the maintenance monitoring unit is encoded into a maintenance monitoring information code set and output to the idle code set replacement unit. The idle code set replacing unit is in a replacement enable state, and when detecting two consecutive idle code sets from the signal, replaces the two detected idle code sets with one maintenance monitoring information code set. I do. The maintenance monitoring unit
Necessary for performing maintenance monitoring of packet communication systems,
Generate maintenance monitoring information.

FIG. 31 is a diagram showing a block configuration of the relay node Rep-i according to the third embodiment. The relay node Rep-i includes a receiving unit, a relay processing unit, and a transmitting unit. The signal is received by the receiving unit and output to the relay processing unit. The relay processing unit
The maintenance monitoring information code set is extracted from the received signal, a signal synchronized with the reception clock is changed to a signal synchronized with the transmission clock, and a part of the idle code set is replaced with a maintenance monitoring information code set obtained by encoding the maintenance monitoring information. The transmitting unit transmits the signal output by the relay processing unit to a downstream relay node.

FIG. 32 shows the block configuration of the relay node relay processing unit according to the third embodiment. The relay processing unit of the relay node Rep-i includes a maintenance monitoring information receiving unit, a clock changing unit, a maintenance monitoring information transmitting unit, and a maintenance monitoring unit. The maintenance monitoring function is as follows. -Monitor the bit error rate by communicating parity as maintenance monitoring information. -Monitor erroneous connections by communicating trace information as maintenance monitoring information. -Route switching at the time of failure is performed by communicating route switching information as maintenance monitoring information.

FIG. 33 is a diagram showing a block configuration of a maintenance monitoring information receiving unit according to the third embodiment, and FIG. 34 is a time chart of signals indicating the operation. The maintenance monitoring information receiving unit
It has a maintenance monitoring information reading unit and an idle code set replacement unit.

The function of the maintenance monitoring information reading section is as follows. A maintenance monitoring information code set is detected from the main signal, read out, and the maintenance monitoring information code set is decoded into maintenance monitoring information.

The function of the idle code set replacement unit is as follows. The maintenance monitoring information code set is detected from the main signal and replaced with two idle code sets.

The maintenance monitoring information reading section reads the maintenance monitoring information code set from the signal and decodes the code into maintenance monitoring information.
Output to the maintenance monitoring unit. The idle code set replacement unit includes:
When the maintenance monitoring information code set is detected from the signal, the detected maintenance monitoring information code set is replaced with two idle code sets. The clock changing unit is the same as the clock changing unit of the relay start node. The maintenance monitoring information transmission unit
This is the same as the maintenance monitoring information transmission unit of the relay start node. The maintenance monitoring unit analyzes the maintenance monitoring information read from the received signal and generates maintenance monitoring information to be transmitted.

FIG. 35 is a diagram showing a block configuration of a relay end node according to the third embodiment. A relay end node, a receiving unit,
A relay processing unit, a communication state determination unit, a relay processing code set discarding unit, and a transmission unit are provided. The signal received by the receiving unit is output to the relay processing unit. The relay processing unit extracts the maintenance monitoring information code set from the received signal, and changes a signal synchronized with the reception clock to a signal synchronized with the transmission clock. The reception state determination unit is the same as the reception state determination unit of the relay start node. When it is determined that the communication state is the auto negotiation communication state, the idle code set discarding unit discards the idle code set inserted between the auto negotiation code sets.

FIG. 36 is a diagram showing a block configuration of the idle code set discarding unit of the relay end node according to the third embodiment.
This block is connected to the destuff section, a FIFO buffer following this, and the stuff section in succession. The write enable is sent from the destuff section to the FIFO, and the read enable is sent from the stuff section to the FIFO. The idle code set discarding unit has a FIFO buffer, and temporarily stores a signal in the FIFO buffer. FI by insertion of idle code set
The amount of accumulation in the FO buffer is reduced. When the accumulation amount of the FIIFO buffer is reduced to the number of bits of the auto negotiation code set or more, the accumulation amount of the FIFO buffer is adjusted by inserting one auto negotiation code set. The transmitting unit transmits the signal output by the relay processing code set discarding unit to the receiving end node.

The function of each unit of the block of the idle code set discarding unit of the relay end node according to the third embodiment is as follows. Destuff section Detects idle code set from main signal. Reception status =
In the AN communication state, the destuff request = True, and when the idle code set is detected, the write enable = Fals during the period of outputting the detected code set.
e. FIFO buffer-When write enable = True, the input main signal is written to the buffer. When write enable = False, writing to the buffer is stopped. • When read enable = True, read and output the main signals from the buffer in the order they were input. When the read enable = False, the read is stopped. When the accumulated amount falls below T _min , the destuff request =
Outputs False. When the accumulated amount falls below _Tmax ,
Outputs staff request = True. • Tmax: Standard accumulation bit number of FIFO buffer -160 bits
(Number of bits of AN code set) Tmin: Minimum number of bits (value smaller than Tmax) to guarantee normal operation of FIFO buffer Stuff part Detects AN code set from main signal. Staff request = Tr
When ue is detected and two consecutive AN code sets of the same pattern are detected, one AN code set of the same pattern is inserted between the detected two code sets. During the insertion period, the read enable is set to False. An idle code set is detected from the main signal. When the communication state = packet communication state, the stuff request = True, and an idle code set is detected, one idle code set is inserted immediately after the detected code set. During the insertion period, the read enable is set to False.

FIG. 37 is a flowchart showing the operation of the idle code set discarding unit of the relay end node according to the third embodiment.

FIG. 38 is a chart showing the operation of the idle code set discarding unit of the relay end node according to the third embodiment.

FIG. 39 is a diagram showing a block configuration of the relay processing unit of the relay end node according to the third embodiment. The relay processing unit of the relay end node has a maintenance monitoring information receiving unit, a clock change unit, and a maintenance monitoring unit. The maintenance monitoring information receiving unit is the same as the maintenance monitoring information receiving unit of the relay node Rep-i. The clock changing unit is the same as the clock changing unit of the relay node Rep-i. The maintenance monitoring unit analyzes the maintenance monitoring information read from the received signal.

Maintenance monitoring function: The bit error rate is monitored by communicating parity as maintenance monitoring information. -Monitor erroneous connections by communicating trace information as maintenance monitoring information. -Route switching at the time of failure is performed by communicating route switching information as maintenance monitoring information.

As described above, according to the present invention, in the gigabit Ethernet communication system, the relay of the independent synchronous system can be performed. In addition, since the relay start node replaces some auto negotiation code sets with idle code sets in the auto negotiation communication state, each relay node performs auto negotiation.
The clock can be replaced by a process common to the packet communication state (insertion / extraction of an idle code set) without determining the communication state of the packet / communication state. Thereby, the relay node is simplified as compared with the first embodiment. Further, a part of the idle code set is replaced with a maintenance monitoring information code set, thereby realizing a maintenance monitoring function of the packet communication system for communicating the maintenance monitoring information between the relay nodes. Thereby, the reliability of the system can be improved. Also in the second embodiment, as in the third embodiment, a part of the idle code set is replaced with the maintenance monitoring information code set, and communication of the maintenance monitoring information is performed between the relay nodes. It is also possible to realize functions.

Note that the transmitting end node and the relay start node may exist in the same device. Similarly, the relay end node and the receiving end node may exist in the same device.
Also, all nodes from the relay start node to the relay end node are not made to be independent synchronous type, but are combined with the conventional subordinate synchronous type relay node, and are made independent synchronous type relay nodes only when clock quality is greatly deteriorated. It is also possible.

[0075]

The present invention realizes an independent synchronization method in a relay node of a packet communication system, and solves the problem that the conventional clock quality deteriorates with an increase in the number of relay stages. As a result, restrictions on the number of relay stages and the relay distance are greatly eased, and an inexpensive reception clock recovery circuit can be used, so that a large-scale and economical packet communication system can be constructed. According to the present invention, the independent synchronization method can be realized in both the auto-negotiation communication state and the packet communication state. According to the present invention, in an auto-negotiation communication state, by mixing an idle code set necessary for realizing an independent synchronization method with an auto-negotiation code set, communication of a maintenance monitoring information code set to which this is applied becomes possible. Maintenance monitoring becomes possible. Furthermore, according to the present invention, the transmitting end node and the receiving end node can transmit and receive in the conventional signal format, so that the present invention can be easily applied to an existing system. As described above, the present invention has an excellent effect that a large-scale packet communication system can be realized economically and easily.

[Brief description of the drawings]

FIG. 1 is a diagram showing a packet communication system of the present invention.

FIG. 2 is a diagram illustrating a signal format transmitted by a transmitting end node according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a block configuration of a relay node Rep-i according to the first embodiment of the present invention.

FIG. 4 is a flowchart illustrating an operation of the relay node Rep-i according to the first embodiment of this invention.

FIG. 5 is a time chart showing the positional relationship of each signal at the time of stuff / destuff according to the first embodiment of the present invention.

FIG. 6 is a diagram illustrating a packet communication system according to a second embodiment of the present invention.

FIG. 7 illustrates a packet communication system according to the present embodiment.
FIG. 3 is a diagram illustrating a signal format transmitted by a transmitting end node.

FIG. 8 is a diagram illustrating a block configuration of a relay start node according to the present embodiment.

FIG. 9 is a diagram illustrating a block configuration of an idle code set insertion unit of a relay start node according to the second embodiment.

FIG. 10 is a flowchart illustrating an operation of an idle code set insertion unit of the relay start node according to the second embodiment.

FIG. 11 is a table illustrating an operation of a relay start node / idle code set insertion unit according to the second embodiment.

FIG. 12 is a diagram illustrating a block configuration of a clock replacement unit according to a second embodiment.

FIG. 13 is a flowchart illustrating the operation of the clock reordering unit according to the second embodiment of the present invention.

FIG. 14 is a time chart showing signals at the time of stuff / destuff in the second embodiment.

FIG. 15 is a diagram illustrating a block configuration of a relay node Rep-i according to the second embodiment.

FIG. 16 is a diagram illustrating a block configuration of a relay node according to the second embodiment.

FIG. 17 is a diagram illustrating a block configuration of an idle code set discarding unit of a relay end anode according to the second embodiment.

FIG. 18 is a flowchart illustrating an operation of an idle code set discarding unit of a relay end anode according to the second embodiment.

FIG. 19 is a time chart illustrating an operation of an idle code set discarding unit of a relay end anode according to the second embodiment.

FIG. 20 is an example of a Gigabit Ethernet communication system to which the present invention is applied.

FIG. 21 is a diagram illustrating a signal format transmitted by a transmitting end node in the gigabit Ethernet communication system according to the third embodiment.

FIG. 22 is a diagram illustrating a block configuration of a relay start node according to the third embodiment.

FIG. 23 is a flowchart illustrating the operation of the communication state determination unit of the relay start node according to the third embodiment.

FIG. 24 is a time chart showing the operation of the idle code set insertion unit of the relay start node according to the third embodiment.

FIG. 25 is a diagram illustrating a block configuration of a relay processing unit of a relay start node according to the third embodiment.

FIG. 26 is a block diagram illustrating a block configuration of a clock replacement unit (302) according to the third embodiment.

FIG. 27 is a flowchart illustrating an operation of a clock changing unit (302) according to the third embodiment.

FIG. 28 is a diagram illustrating a time relationship of each signal at the time of stuff / destuff according to the third embodiment.

FIG. 29 is a diagram illustrating a block configuration of a maintenance monitoring information transmitting unit according to the third embodiment.

FIG. 30 is a maintenance monitoring information transmission unit (306) of the third embodiment.
FIG.

FIG. 31 is a diagram illustrating a block configuration of a relay node Rep-i according to the third embodiment.

FIG. 32 is a diagram illustrating a block configuration of a relay processing unit of the relay node according to the third embodiment.

FIG. 33 is a diagram illustrating a block configuration of a maintenance monitoring information transmitting unit according to the third embodiment.

FIG. 34 is a time chart of a signal indicating an operation of the maintenance monitoring information transmitting unit according to the third embodiment.

FIG. 35 is a diagram illustrating a block configuration of a relay end node according to the third embodiment.

FIG. 36 is a diagram illustrating a block configuration of an idle code set discarding unit of a relay end node according to the third embodiment.

FIG. 37 is a flowchart illustrating an operation of an idle code set discarding unit of the relay end node according to the third embodiment.

FIG. 38 is a chart illustrating an operation of an idle code set discarding unit of the relay end node according to the third embodiment.

FIG. 39 is a diagram illustrating a block configuration of a relay processing unit of the relay end node according to the third embodiment.

FIG. 40 is a block diagram of a conventional packet communication system.

FIG. 41 is a diagram of a signal format transmitted by a conventional transmitting end node.

FIG. 42 is a block diagram of a conventional relay node Rep-i.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K030 GA12 HA08 JA11 KA03 KA21 LA15 LB14 LC18 MA13 MB15 5K034 AA06 DD03 EE11 FF11 HH50 HH58 MM13 PP02 5K047 AA05 BB15

Claims (12)

[Claims] 1. A packet including a transmitting end node, M relay nodes (M is an integer of 1 or more), and a receiving end node, the packet including a packet and an idle code set transmitted from the transmitting end node. The inter-signal is relayed to the receiving end node by relaying the M relaying nodes, and the packet communication state and the continuously repeated auto-negotiation code set transmitted from the transmitting end node are transmitted to the M relay nodes. A packet communication method for a packet communication system having an auto-negotiation communication state for relaying and communicating with a receiving end node, wherein at least one relay node has a FIFO buffer and a transmission clock generation source; The signal is input to the FIFO buffer, and the output of the FIFO buffer is synchronized with the transmission clock output from the transmission clock generation source. , Send, FI
When the accumulated amount of the FO buffer exceeds _Smax , when the received signal includes an idle code set, the idle code set is discarded. When the received signal includes the auto negotiation code set, the auto negotiation code set is discarded. Discarding, when the accumulation amount of the FIFO buffer falls below S _min , when the received signal includes an idle code set, immediately before or immediately after the idle code set is inserted, and when the received signal includes the auto negotiation code set ,
A packet communication method characterized by inserting an auto negotiation code set immediately before or immediately after that, and transmitting it downstream. 2. A transmitting end node, M relay nodes,
A packet communication state comprising: a receiving end node; a packet transmitted from the transmitting end node; and an inter-packet signal including an idle code set, which is relayed to the receiving end node by relaying the M relay nodes. An auto-negotiation communication state for transmitting a continuously repeated auto-negotiation code set transmitted from the transmitting end node to the receiving end node by relaying the M relay nodes, In a relay node device of a packet communication device, at least one relay node has a FIFO buffer and a transmission clock generation source, inputs a reception signal to the FIFO buffer, and outputs a FIFO buffer output from the transmission clock generation source. Synchronize with the transmission clock and transmit, FI
When the accumulated amount of the FO buffer exceeds _Smax , when the received signal includes an idle code set, the idle code set is discarded, and when the received signal includes the auto-negotiation code set, the auto-negotiation code set is discarded. Discarded, and the accumulated amount of the FIFO buffer becomes S
If the value is less than _min , the idle code set is inserted immediately before or immediately after the idle signal set is included in the received signal, and the auto negotiation code set is inserted immediately before or immediately after the received signal includes the auto negotiation code set. A relay node device, wherein a relay node device is inserted and transmitted downstream. 3. The packet communication device according to claim 2, wherein the relay node (Rep-i) has the following constituent elements: a receiving unit; a destuff unit connected to the receiving unit; A buffer, a stuff section following the FIFO buffer, a transmitting section following the stuff section, a transmission clock source connected to transmit the transmission clock to the FIFO buffer, the destuff section detects an idle code set from the main signal, When stuff request = True and idle code set is detected, write enable = False during output of detected code set. Further, AN code set is detected from main signal. Destuff request = True and AN code. When a set is detected, write enable = Fa during the period of outputting the detected code set.
has a function to lse, the stuff unit detects an idle code set from the main signal, when detecting a stuff request = True and idle code set, insert an idle code set immediately after the detected code set, In addition, during the insertion period, read enable = False. Further, when the AN code set is detected from the main signal. When the stuff request = True and the AN code set is detected, the AN code set is inserted immediately after the detected code set. In addition, the FIFO buffer has a function of setting read enable = False during the period. When the write enable = True, the FIFO buffer writes a main signal input in synchronization with a reception clock to the buffer, and sets the write enable = False. When writing to the buffer is stopped, read enable = Tr
When ue, read and output in the order of input of the main signal from the buffer in synchronization with the transmission clock, and read enable = Fa
When lse, the reading is stopped. The output of the FIFO buffer is transmitted in synchronization with the transmission clock output from the transmission clock generation source. If the accumulated amount of the FIFO buffer exceeds _Smax , the output of the FIFO buffer is idle. When the code set is included, the idle code set is discarded. When the received signal includes the auto-negotiation code set, the auto-negotiation code set is discarded. When the accumulation amount of the FIFO buffer falls below S _min , the reception When the signal includes the idle code set, insert the idle code set immediately before or immediately after the signal.When the received signal includes the auto negotiation code set, insert the auto negotiation code set immediately before or immediately after the signal, and transmit downstream. A relay node device. 4. A transmitting end node, a relay start node, and M
And a relay end node, a relay end node, and a reception end node.
A packet communication method for a packet communication system, comprising: an auto-negotiation communication state for relaying the relay node and the relay end node to communicate with the receiving end node. Inserting at least one idle code set between at least one auto negotiation code set and the immediately succeeding auto negotiation code set among the continuously repeated auto negotiation code sets received during the period. And transmitting the data downstream. 5. A transmitting end node, a relay start node, and M
And a relay end node, a receiving end node, and a packet transmitted from the transmitting end node and an inter-packet signal including an idle code set are transmitted to the relay start node and the M relay nodes. A packet communication state for relaying to the receiving end node by relaying to the relay end node, and a continuously repeated auto negotiation code set transmitted from the transmitting end node are transmitted to the relay starting node and M
A packet communication device having an auto-negotiation communication state for relaying the relay nodes and the relay end node to communicate with the receiving end node, wherein the relay start node is in the auto-negotiation communication state. Inserting at least one idle code set between at least one auto negotiation code set and the immediately succeeding auto negotiation code set among the continuously repeated auto negotiation code sets received during the period. A relay start node device for transmitting downstream. 6. The packet communication device according to claim 5, wherein the relay start node device includes a receiving unit, an idle code set inserting unit following the receiving unit, a clock switching unit following the receiving unit, and a downstream transmitting unit. The relay start node has a destuff section and a subsequent FI
An FO buffer, and a stuff section downstream thereof, wherein the destuff section detects an AN code set from the main signal, and when the destuff request = True, and detects the AN code set, During the period of outputting the detected code set, the write enable is set to False, and when the write enable is True, the FIFO buffer writes the input main signal to the buffer. When write enable = False, writing to the buffer is stopped. When read enable = True, the main signals are read out and output in the order in which they were input from the buffer. When read enable = False, reading is stopped. When the accumulation amount is equal to or more than _Rmin , the destuff request = True is output, and when the accumulation amount is equal to or more than _Rmax , the stuff request = True is output. _Rmin : standard number of accumulation bits of FIFO buffer + AN code The number of bits per set, R _max : the minimum number of accumulated bits (greater than R _min ) to guarantee the normal operation of the FIFO buffer; the stuff section detects an AN code set from the main signal; When the stuff request = True, the idle code set insertion timer indicates that the time Ti has elapsed, and the AN code set is detected, the detected code set is After that, one idle code set is inserted. During the insertion period, the read enable is set to False, and after the insertion, the idle code set insertion timer is configured to be reset, and received during the period of the auto-negotiation communication state.
At least one idle code set is inserted between at least one auto negotiation code set and the immediately succeeding auto negotiation code set among the continuously repeated auto negotiation code sets, and transmitted downstream. A relay start node device, characterized in that: 7. The packet communication method according to claim 4, wherein the relay start node receives at least one of a continuously repeated auto negotiation code set received during a period of the auto negotiation communication state. A packet communication method comprising: transmitting a plurality of auto-negotiation code sets downstream by replacing at least one idle code set. 8. The packet communication device according to claim 4, wherein the relay start node has an idle code set replacement unit,
Received within the period of the auto-negotiation communication state,
A packet communication device characterized by replacing at least one auto negotiation code set among continuously repeated auto negotiation code sets with at least one idle code set and transmitting the packet downstream. 9. The packet communication method of the communication system according to claim 4, wherein the relay end node sets n (n) consecutive numbers between the received auto-negotiation code set and the next auto-negotiation code set. (n is a natural number) When the idle code set is received, these idle code sets are removed and the packet is transmitted downstream. 10. The packet communication device according to claim 4, wherein the relay end node has an idle code set discarding unit, and the idle code set discarding unit includes a destuff unit and The following FIFO buffer has a stuff section following the FIFO buffer. The destuff section detects an idle code set following the AN code set from the main signal, and has a destuff request = True and an idle code following the AN code set. When the code set is detected, during the period of outputting the detected code set,
When write enable = False, when the write enable = True, the FIFO buffer writes the input main signal to the buffer. When the write enable = False, the FIFO buffer stops writing to the buffer, and read enable = True. when, the output reads the order of input of the main signal from the buffer, when the read enable = False, it stops reading, when the accumulation amount falls below T _min is destuffing request = Fal
Output se. When the accumulated amount falls below _Tmax , staff request = True
(T _max : standard number of accumulated bits of FIFO buffer−number of bits of AN code set,
T _min : the minimum number of accumulated bits for guaranteeing the normal operation of the FIFO buffer (value smaller than T _max )
The stuff unit detects an AN code set from the main signal, and when stuff request = True and detects an idle code set, inserts one AN code set immediately after the detected code set. During the period, the read enable = False function is provided, and when n consecutive (n is a natural number) idle code sets are received between the received auto negotiation code set and the next auto negotiation code set And transmitting the packet downstream, excluding these idle code sets. 11. The packet communication method of the communication system according to claim 4, wherein the relay node has a FIFO buffer and a transmission clock generation source, and inputs a reception signal to the FIFO buffer.
The output of the O-buffer is transmitted in synchronization with the transmission clock output from the transmission clock generation source. When the accumulation amount of the FIFO buffer exceeds _Smax , when the idle code set is included in the received signal, this idle code is output. When the set is discarded and the amount of accumulation in the FIFO buffer falls below S _min , when the received signal includes the idle code set, the idle code set is inserted immediately before or immediately after the set and transmitted downstream. , Packet communication method. 12. The packet communication device according to claim 4 or 7, further comprising a receiving unit, a relay processing unit, and a transmitting unit, wherein the relay processing unit includes a clock switching unit. The clock replacement unit includes a destuff unit and a subsequent FI
The FO buffer further includes a stuff section following the FO buffer. The destuff section detects an idle code set from the main signal. The destuff request = True, and the detected code set is detected when the idle code set is detected. Has a function of setting write enable = False during the period of outputting the data. When the write enable = True, the FIFO buffer writes the main signal input in synchronization with the reception clock to the buffer. When False, stop writing to the buffer. When Read Enable = True, read and output the main signals from the buffer in the order in which they were input in synchronization with the transmission clock. When Read Enable = False, read Stop, when the accumulated amount exceeds _Smax , destuff request = True
Is output. When the accumulated amount falls below S _min , the staff request = True
The stuff unit outputs an idle code set or A from the main signal.
Detect N code sets, stuff request = True and idle code set or AN
When a code set is detected, an idle code set is inserted immediately after the detected code set. In addition, during the insertion period, a read enable = False function is provided. Input the received signal to the FIFO buffer,
The output of the O-buffer is transmitted in synchronization with the transmission clock output from the transmission clock generation source, and when the accumulated amount of the FIFO buffer exceeds _Smax , the idle code When the set is discarded and the amount of accumulation in the FIFO buffer falls below S _min , when the received signal includes the idle code set, the idle code set is inserted immediately before or immediately after the set and transmitted downstream. , Relay node device.