CN1204717C

CN1204717C - A Method of Automatic Correction of Signal Line Propagation Delay in Network Trunk Line Group

Info

Publication number: CN1204717C
Application number: CNB001341243A
Authority: CN
Inventors: 卓裕文; 张至皓
Original assignee: D Link Corp
Current assignee: D Link Corp
Priority date: 2000-12-04
Filing date: 2000-12-04
Publication date: 2005-06-01
Anticipated expiration: 2020-12-04
Also published as: CN1358002A

Abstract

A method for automatically correcting the propagation delay of signal line in trunk group of network includes setting a counter on two network exchangers connected correspondingly in network exchange system, calculating out the delay Tx caused by each network channel of two network exchangers to trunk data packet by correlation formula according to count of counter, correcting propagation delay when received trunk data packet is decoded by network exchanger, judging out time gap between data packets in same network channel accurately, reducing said trunk data packet to data stream correctly to complete transmission of data packet and reducing possibility of upper software layer waiting for or giving up a sequence data stream due to data stream sequence error.

Description

The method of holding wire propagation delay in a kind of automatic correcting network trunk group

Technical field

The present invention relates to the method for holding wire propagation delay among a kind of automatic correcting network trunk line (trunk) group, especially refer to a kind of in the technical field of express network now, be applied to the interior technology of network of relation devices such as hub, router or interchanger of internet exchange system, to cause the problem of packet propagation delay (propagation delay) among network trunk line (trunk) group between this network equipment of effective solution because of the holding wire (as twisted-pair feeder) that uses different length, can reach instant consistency with the trunk data bag order of guaranteeing data flow.

Background technology

In recent years, owing to the rise of local area network (LAN) and wide area network, not only enlarged the channel of message transmission, the speed and the quality of information flow have been improved, more under the adding fuel to the flames of high-performance low-price computers, effectively reduce the cost that information transmits, significantly promoted convenience and popularization that information transmits.On network, transmit data,, nowadays become enterprises or the enterprise instrument of daily information communication to each other with exchange message.

The network manufacturer is for promoting the efficiency of transmission of legacy network system, frequent circuit with the network interface that a plurality of transmission rates are lower on the network, by an internet exchange system, lump together, to obtain the circuit of a whole frequency range broad,, promote the transmission speed and the efficient of legacy network system by this internet exchange system, this kind will be commonly referred to as line lump (linkaggregation) with a kind of signal line lump technology together.

The network manufacturer is at the designed internet exchange system of aforementioned need at present, as shown in Figure 1, with the network line 20 lumps internet exchange system 10 together with 10 10Mb is example, and this internet exchange system 10 comprises at least two network switchs 11 and 12.The packet of the data flow (data stream) that one computer terminals 3 is transmitted, can be earlier via a network switch 11 to its encoding process of carrying out after, be redistributed to this network line 20 formed different channels (channel), and with transmission rate near 100Mb/s, this packet is sent to another network switch 12, again via the decoding processing of this another network switch 12 to it, after being reduced into this data flow, the packet of this data flow is sent to another computer terminals 4, finishes the transmission work of packet.

This practice, though can effectively promote the transmission speed and the efficient of legacy network system in theory really, regulation owing to according to IEEE 802.3ad does not allow internet exchange system in transmission course the packet in the trunk group to be resolved into small fragment but in fact.The restriction of this standard forces the network manufacturer when this kind of design internet exchange system, for keeping the integrality of packet in transmission, must sacrifice the efficiency of transmission of network system.With aforementioned legacy network switching system is example, after 12 packets among data flow (data stream) A that 11 pairs of tendencies to develop of this network switch are sent carry out encoding process, this packet is assigned to this network line 20 formed 10 channels (channel), consult shown in Figure 2, and with the transmission rate of about 100Mb/s, be transferred into another network switch 12 simultaneously, owing to the packet that is numbered 1 in this packet is longer, the time of its busy channel is also longer, and it is shorter to be numbered 7 packet, the time of its busy channel is also shorter, so when the packet that is numbered 7 arrives at this another network switch 12, this be numbered 1 packet still busy channel transmit, so after this another network switch 12 each packet in must same trunk group all is received, could be one by one to its reduction of decoding.So for keeping the integrality of packet in transmission, general processing mode is with the packet in next trunk group, with packet the longest in the last trunk group is benchmark, send in same sequential by this network switch 11, cause the time difference Td that the generation of adjacent data parlor transmits in each channel, cause network system can't reach the transmission rate of expection.

When this kind internet exchange system transmits the packet of each trunk group under different sequential, mainly be that to utilize this network switch 11 be that sequencing is initial with the front end of each packet of data flow, and insert a time slot Ts who sets respectively at each packet tail end of a trunk group, consult shown in Figure 3, this another network switch 12 is discerned each packet of different trunk groups in the same channel according to this time slot Ts.But this design, because when setting up this internet exchange system, these two

network switchs

11 and 12 are to connect with holding wire (as twisted-pair feeder), on its formed each network channel (channel) 20, normal length because of holding wire sets and differs, very easily produce different data dissemination time delays (propagationdelay), make this another network switch 12 can't accurately judge this time slot Ts, and then cause accurately sorting data bag of network system, make the packet that is received to reach instant consistency, thereby require the upper layer software (applications) layer to possess ranking function, otherwise can't guarantee the succession of each packet in the trunk data stream, and then cause in the identification of packet and the mistake in the transmission.

Summary of the invention

Main purpose of the present invention is in view of aforementioned conventional internet exchange system existing many disappearances when transmitting the trunk data bag, and the method for holding wire propagation delay in a kind of automatic correcting network trunk group is provided.

The method of holding wire propagation delay in a kind of automatic correcting network trunk group of the present invention, this method comprises: on two corresponding network switchs that connect a counter is set respectively in an internet exchange system; Wherein this counter calculates a network switch after sending a mark bag (mark), receives a required time T i of mark bag that acknowledges receipt of the trunk data bag who is transmitted by another network switch to it; Another counter calculates this another network switch after receiving this mark bag and trunk data bag, produces the required time T t of mark bag that the trunk data bag is received in this affirmation to it; During to this network switch, with this time value Tt, addition record is in the mark bag that this affirmation is received at the token-passing that will confirm to accept for this another network switch; This network switch can read time value Tt after receiving the mark bag that this affirmation receives, calculate the time delay Tx that each network channel is caused this trunk data bag between this two network switch according to formula Tx=(Ti-Tt)/2 again; When this network switch is decoded to the trunk data bag that is received, can proofread and correct the propagation delay (propagationdelay) on this network channel respectively according to this time delay Tx, accurately to judge the time slot between each packet in the consolidated network channel, correctly this trunk data bag is reduced into data flow, finishes the transmission work of packet.

Effect of the present invention is: by on two corresponding network switchs that connect the problem that a counter effectively solves packet propagation delay (propagation delay) among network trunk line (trunk) group who causes because of the holding wire that uses different length between network equipment is set respectively in an internet exchange system, reach instant consistency in proper order with the trunk data bag of guaranteeing data flow.

Description of drawings

Figure 1 shows that the formation schematic diagram of legacy network switching system;

Figure 2 shows that the transmission time sequence figure of packet in each channel of each trunk group in the legacy network switching system;

Figure 3 shows that the transmission time sequence figure of packet in each channel of each trunk group in another legacy network switching system;

Figure 4 shows that the time sequence status schematic diagram when packet transmits in the internet exchange system of the present invention in each channel.

Embodiment

The present invention is described in detail below in conjunction with accompanying drawing.

Use now in the internet exchange system of line lump technology, one network switch 11 is passing through each node (node) on it, send a data flow (data stream) with trunking scheme, with wherein packet via the formed different channels of at least one above network line 20 (as twisted-pair feeder) (channel), when being sent to relative each node of another network switch 12, on this network switch 11 respectively this node (node) set one send logical one 11 (transmitter), consult shown in Figure 1, must be according to the regulation of IEEE 802.3ad, send the mark bag (marker) of a special requirement earlier, as shown in table 1, it is the mark bag (marker) according to the special requirement that regulation sent of IEEE802.3ad.

This mark bag passes through respectively this network line 20, is transmitted in the relative set receive logic 121 (receiver) of each node on another network switch 12, makes this receive logic 121 receive the packet that transmits.After finishing reception this data flow (data stream) packet, each node on this another network switch 12, will be by a transmission logical one 22 (transmitter) set on it, regulation according to IEEE 802.3ad, send another mark bag (acknowledgement marker), and being sent on this network switch 12 the set receive logic 112 (receiver) of each node relatively by this network line 20 respectively, notice has been finished the reception of this data flow data bag.

Because, IEEE 802.3ad rules each trunk data bag in network system, transmitting, be defined in the process of its transmission and reception, the mark bag (acknowledgement marker) that two

corresponding network switchs

11,12 that connect must acknowledge receipt of by the mark bag and that transmission logic (transmitter) on it and receive logic (receiver) produce respectively is with the transmission and the reception of the packet that carries out data flow.In this communication process, consult shown in Figure 4 because this two network switchs 11,12 send and when receiving the packet of same data flow, required time T t is identical, these two net lists 1:

Eight (Octets) marks of mark PDU (Marker PDU) response PDU (Marker Response PDU)

Destination address (Destination Address)	6	Destination address (Destination Address)
Destination address (Destination Address)	6	Destination address (Destination Address)	Source address (Source Address)	6	Source address (Source Address)
Length/type (Length/Type)	2	Length/type (Length/Type)	Source address (Source Address)	6	Source address (Source Address)
Length/type (Length/Type)	2	Length/type (Length/Type)	Subtype=mark (Subtype=Marker)	1	Subtype=mark (Subtype=Marker)
Version number (Verslon Number)	1	Version number (Verslon Number)	Subtype=mark (Subtype=Marker)	1	Subtype=mark (Subtype=Marker)
Version number (Verslon Number)	1	Version number (Verslon Number)	TLV_ type=label information (TLV_type=Marker Inforrnation)	1	TLV_ type=mark response message (TLV_type=Marker Response Information)
Mark _ information _ length=16 (Marker_Information_Length=16)	1	Mark _ reply _ information _ length=16 (Marker_Response_Information_Length=16)	TLV_ type=label information (TLV_type=Marker Inforrnation)	1
	1		Request _ port (Requester_Port)	2	Request _ port (Requester_Port)
Request _ system (Requester_System)	6	Request _ system (Requester_System)	Request _ port (Requester_Port)	2	Request _ port (Requester_Port)
Request _ system (Requester_System)	6	Request _ system (Requester_System)	Request _ transaction _ ID (Requester_Transaction_ID)	4	Request _ transaction _ ID (Requester_Transaction_ID)
Decay=0 (Pad=0)	2	Decay=0 (Pad=0)	Request _ transaction _ ID (Requester_Transaction_ID)	4	Request _ transaction _ ID (Requester_Transaction_ID)
Decay=0 (Pad=0)	2	Decay=0 (Pad=0)	TLV_ type=final selector (TLV_type=Terminator)	1	TLV_ type=final selector (TLV_type=Terminator)
Final selector _ length=φ (Terminator_Length=φ)	1	Final selector _ length=0 (Terminator_Length=0)	TLV_ type=final selector (TLV_type=Terminator)	1	TLV_ type=final selector (TLV_type=Terminator)
Final selector _ length=φ (Terminator_Length=φ)	1	Final selector _ length=0 (Terminator_Length=0)		1
Clock _ counter=0 (Clock_Counter=0)	2	Clock _ counter=n (Clock_Counter=n)		1
Clock _ counter=0 (Clock_Counter=0)	2	Clock _ counter=n (Clock_Counter=n)	Keep (RESERVED)	88	Keep (RESERVED)
Frame Check Sequence (FCS)	4	Frame Check Sequence (FCS)	Keep (RESERVED)	88	Keep (RESERVED)

The mark bag (marker) that

interchanger

11,12 is produced, required time T x when respectively this network line 20 is transferred into another network switch also is identical from a network switch, the time delay Tx that former respectively 20 pairs of data stream packets of this network line are caused, can calculate by following formula: Tx=(Ti-Tt)/2, wherein Ti represents that sending a mark bag from a network switch receives the required time of mark bag that acknowledges receipt of of being transmitted by another network switch until it.

The present invention utilizes this notion, at this network switch 11 respectively, one counter (counter) is set respectively on 12, calculate respectively from this network switch 11 by this counter and to receive this required time T i of mark bag that acknowledges receipt of that transmits by this another network switch until it sending this mark bag, and produce the required time T t of mark bag that this acknowledges receipt of until it receiving this mark bag from this another network switch 12, and make this another network switch 12 when the mark bag that this is acknowledged receipt of is sent to this network switch 11, with this time value Tt addition record in the mark bag that this is really received, after this network switch 11 receives this mark bag that acknowledges receipt of, can be by reading this time value Tt, according to aforementioned formula Tx=(Ti-Tt)/2, calculate the respectively time delay Tx that packet caused of 20 pairs of data flow of this network line again.

The present invention is provided with a register (register) respectively again on this

network switch

11,12, utilize respectively this register, writes down the propagation delay that the circuit 20 of each node n correspondence on this

network switch

11,12 is caused.Order is this network switch 11 respectively, 12 maximum of T max with the propagation delay of each corresponding line 20, fiducial value as the internal communication time delay adjustment, to comply with following formula: Ts (n)=Tmax-Tx (n) again according to this correction reference value, propagation delay Tx (n) to the circuit 20 of each node n correspondence, calculate the corrected value Ts (n) of propagation delay, with when 12 pairs of packets that received of this another network switch are decoded one by one, propagation delay is proofreaied and correct, to judge the time slot Ts between each packet in the same channel exactly, correctly be reduced into data flow, finish the transmission work of packet.

So, when internet exchange system is being handled the packet of each trunk group that transmits under the different sequential, respectively this network switch can be according to the propagation delay Tx (n) of the circuit 20 of each node n correspondence of being calculated, accurately debate and know this time slot Ts, make the packet that is received effectively to reach instant consistency, and guarantee the reception succession of each packet in the trunk data stream to make packet in identification and transmission, the problem of unlikely generation error of transmission.

Claims

1. A method for automatically correcting signal line propagation delay in a network trunk group, characterized in that the method comprises:

Setting a counter on two correspondingly connected network switches in a network switching system;

One of the counters calculates the time Ti required for a network switch to receive a mark packet confirming receipt of the trunk data packet from another network switch after sending a mark packet;

Another counter calculates the time Tt required for the other network switch to generate the marker packet for confirming receipt of the trunk data packet after receiving the marker packet and the trunk data packet;

The other network switch additionally records the time value Tt in the mark packet confirming acceptance when transmitting the mark confirming acceptance to the network switch;

The network switch can read the time value Tt after receiving the marked packet that confirms acceptance, and then calculates the trunk line data packet according to each network channel between the two network switches according to the formula Tx=(Ti-Tt)/2 The resulting time delay Tx;

When the network switch decodes the received trunk line data packet, it can correct the propagation delay on each network channel according to the time delay Tx, so as to accurately judge the time gap between each data packet in the same network channel, correct Revert the trunk packet into a data stream.

2. A method for automatically correcting the propagation delay of signal lines in a network trunk line group as claimed in claim 1, wherein each node n on the two correspondingly connected network switches passes through a sending logic thereon A marker packet and a marker packet acknowledging receipt generated respectively by the receiving logic and the receiving logic are used to transmit and receive the corresponding inter-node data packets.

3. A method for automatically correcting the propagation delay of signal lines in a network trunk line group as claimed in claim 2, characterized in that the network switch is respectively provided with a register, and each register is used to record the line corresponding to the node n The resulting propagation delay.

4. A method for automatically correcting the propagation delay of signal lines in a network trunk line group as claimed in claim 3, wherein each network switch uses the maximum value Tmax of the propagation delay of each corresponding line as the internal propagation delay. The reference value of time delay correction, according to the correction reference value, according to the following formula: Ts(n)=Tmax-Tx(n), for the propagation time delay Tx(n) of the line corresponding to each node n, calculate the propagation time Delayed correction value Ts(n).

5. A method for automatically correcting the propagation delay of signal lines in a network trunk line group as claimed in claim 4, wherein each network switch decodes the received data packets one by one according to the correction value Ts (n), correcting the propagation delay caused by the line corresponding to each node n, so as to accurately determine the time gap Ts between the data packets in the same channel, and correctly restore the data stream.