CN1972234A - Ring shape Ethernet and its service loading implementation method - Google Patents

Abstract

This invention discloses one ring Ethernet and its business load realization method, wherein, the ring Ethernet comprises multiple network points device connected by one reverse physical linkage, wherein, each point adopts special Ethernet type label tropical find data frame index ring structure to establish tropical image; in business loading, on business source point sealing Ethernet data into ring network data frame and sending to top ring Ethernet; ring each point transferring the images according to the tropical image; peeling off data on business aim point.

Description

Ring-like Ethernet and service bearer implementation method thereof

Technical field

The present invention relates to network communications technology field, be specifically related to a kind of ring-like Ethernet and service bearer implementation method thereof.

Background technology

At present, the looped network technology of Ethernet mainly contains two kinds of EAPS (Ethernet automatic protective system) and RPR (Resilient Packet Ring).

EAPS is used for providing quick protection to the ring-like topology of Ethernet.This machining function is in Ethernet ring interconnection topology structure, and do not need to increase new hardware and interface.It is an EAPS territory that EAPS looks around single.Arbitrary VLAN (VLAN) that needs error protection will be arranged to comprise all of the port on the ring, then this VLAN is assigned to an EAPS territory.On this ring territory, a switch is set as host node, and all other switches are designated as excessive node.The port that host node is connected to ring is designated as the master port of host node, and another port that host node is connected to ring is set as the subordinate port of host node.Under normal circumstances, host node stops up on the subordinate port and belongs to all non-control informations in this EAPS territory, thereby has avoided forming the loop on a ring.The exchange and the study mechanism of the second layer are moved according to existing standard on this ring.

The EAPS cost is low, and a ring only needs the support of a host node equipment to get final product, and any switch can support, does not rely on concrete hardware platform.

But the EAPS ring must have a port to block under normal condition, and therefore the bandwidth from any one source node to any one destination node all has only the bandwidth of a monocycle.Because detection and the action that all is based on a node of host node switched in all protections of EAPS, if the host node fault, then whole EAPS ring can lose the function that protection is switched.When carrying out fault detect, detect Frame and need cross over node on all rings, and the address on the ring needs refresh all, very difficult assurance 50ms guard time under any circumstance when EAPS protects.

In order to improve the looped network bandwidth availability ratio, the RPR net designs based on the requirement of grouping metropolitan area network.It is by the loop network that Packet Switch Node is formed, and adjacent node connects by a pair of reverse physical pathway, and its network topology is based on two rightabout transmission rings, along the outer shroud that cries that transmits data clockwise, along the interior ring that cries that transmits data counterclockwise.The RPR technology is a kind of MAC (medium access control) layer protocol that data service transmits of optimizing on ring topology, can adapt to multiple physical layer medium, can transmit the data of multiple business types such as speech, image effectively.It has merged the characteristics such as economy, flexibility, extensibility of ethernet technology; the 50ms that has absorbed SDH (SDH (Synchronous Digital Hierarchy)) looped network simultaneously is the advantage of protection fast, and have that network topology is found automatically, loop bandwidth is shared, bandwidth fair allocat, strict COS functions such as (professional classification).

But also there is following defective in existing RPR looped network:

(1) in order to guarantee that the bandwidth from any one node to the another one node on the RPR ring all is that the endless belt of twice is wide, need encapsulate one deck PRP mac frame head in addition to the Frame of last RPR ring;

(2) in order to support multicast functionality, make same multicast packet frame on ring, to transmit along two rings simultaneously, utilize the bandwidth of PRP dicyclo better, need that also RPR data frame head is TTL (life span) and handle;

(3), that is to say the business and the business of crossing ring of ring, so RPR MAC chip needs sheet outer data buffering storage and TM (telecommunication management) technology because RPR exists two groups of physical ports to send professional situation to same group of physical port;

(4) frame format of RPR and encapsulation realize complicated.

Summary of the invention

The purpose of this invention is to provide a kind of ring-like Ethernet, realize the shortcoming of cost height, business realizing complexity, reduce ethernet ring network and realize cost, improve the ethernet ring network ability to overcome existing RPR looped network.

Another object of the present invention provides a kind of ring-like Ethernet service carrying implementation method, makes ethernet ring network can realize carrying to two layer services simply, and for business provides quick protective switch, improves QoS.

For this reason, the invention provides following technical scheme:

A kind of ring-like Ethernet, comprise: a plurality of apparatus for network node, be used for business datum sent on the ring-like Ethernet or from ring-like Ethernet and receive business datum, each apparatus for network node receives and is connected respectively on the different adjacent node equipment with the different physical ports that send same looped network Frame; Adjacent apparatus for network node connects by a pair of reverse physical link, is used for the business datum between transport network node; Two layer services of described physical link carrying are the looped network Frame of a two-layer media access control MAC encapsulation format.

Before the business datum of each apparatus for network node ring on sending the ethernet data frame that receives is packaged into the looped network Frame with two-layer MAC encapsulation format.

The outer MAC head of the described looped network Frame that will receive before the business datum of each apparatus for network node ring under sending is peeled off.

Each apparatus for network node adopts the ethernet data frame with special ethernet type sign to realize encircling upper topology and finds automatically and fault detect that described ethernet data frame with special ethernet type sign is an individual layer MAC encapsulation format.

A kind of service bearer implementation method of ring-like Ethernet comprises:

Each node adopts the Topology Discovery Frame of special ethernet type sign to collect ring-like Ethernet topological structure on A, the ring, sets up network topological diagram separately;

B, at the service source node, ethernet data frame is encapsulated as the looped network Frame, and it is served ring-like Ethernet;

Each node is transmitted described looped network Frame according to the network topological diagram of its foundation on C, the ring;

D, at the business purpose node, described looped network Frame is peeled off ring-like Ethernet.

Described method further comprises step:

The topological checking data frame that timed sending adopts special ethernet type to identify between adjacent node on E, the ring carries out ring network fault and detects;

F, the node that detects fault are gone up every other node to ring and are sent the fault data frame, and fault message notice ring is gone up every other node.

Described method further comprises step:

G, when breaking down, carry out loopback Wrap protection by the node that breaks down earlier and switches on ring, after the status data of each node was restrained again and be stable, all nodes carried out source routing Steer again and protect and switch on the ring.

Described steps A comprises:

A1, each node regularly adopt the multicast mode to send described Topology Discovery Frame;

A2, receive that the node of described Topology Discovery Frame adds the mac address information of oneself in this Topology Discovery Frame;

A3, receive the Topology Discovery Frame that oneself sends when the source sending node after, set up the network topological diagram of oneself according to the media access control MAC address information of each node in this Topology Discovery Frame.

In described step B, in the following manner ethernet data frame is encapsulated as the looped network Frame:

At the outer MAC Address head that increases for ring-like Ethernet identification of ethernet data frame, target MAC (Media Access Control) address in the MAC Address head extends this as the target MAC (Media Access Control) address of described looped network Frame, source MAC extends this as the MAC Address of this node, ethernet type extends this as ring and goes up the particular values that node uses, virtual LAN VLAN priority extends this as priority on the ring of this ethernet data frame, the VLAN sign extends this as the ring ID that need send to, and identifies the ethernet data frame that needs inundation with conventional form Warning Mark CFI.

Determine priority on the ring of described ethernet data frame in the following manner:

Determine according to the priority mapping in the looped network Frame internal layer MAC head; Perhaps

Access control list ACL or service quality QOS specification according to looped network Frame internal layer static load are determined.

Described step C comprises:

C1, this node are judged the type of the looped network Frame that receives;

C2, the network topological diagram of setting up according to described type and this node are transmitted this looped network Frame;

C3, carry out MAC address learning, be specially: the source MAC in the looped network Frame internal layer MAC head is learnt under the source MAC in the outer MAC head, and the MAC address learning on will two rings of this ring-like Ethernet together.

Described step D further comprises:

When the looped network Frame is peeled off, the source MAC in the internal layer MAC head of looped network Frame is learnt under the source MAC in the outer MAC head.

By above technical scheme provided by the invention as can be seen, the present invention adopts RPR to become the method for ring to make Ethernet Cheng Huan, make up ring-like Ethernet, and adopt MAC encapsulation format of individual layer, and special ethernet type numerical value identify the Topology Discovery Frame, realize the upward topological automatic discovering of each node of ring, make ring go up each node and can form the topological diagram of oneself.The ethernet data frame that transmits on the ring adopts a two-layer MAC encapsulation format, goes up the forwarding of each node according to the topological diagram realization Layer 2 data frame of oneself by ring, comprises that unknown unicast is transmitted, known unicast is transmitted and the multicast/broadcast forwarding capability.Realize that by the Hello Frame that encircles between the adjacent node ring network fault detects; after looped network breaks down; by sending out all nodes on the fault data frame notice ring; making the node that breaks down carry out the Wrap protection switches; transmission switching services on the ring is sent to the another one ring; after ring is gone up all nodes and is all obtained the variation of loop network topology structure, carry out the Steer protection and switch, readjust the professional route that sends and the flow of transmission.Thereby realized fault detect and maintenance, guaranteed the normal forwarding of customer service ring-like Ethernet.

This ring-like Ethernet has not only possessed all functions of RPR looped network, and Business Processing is simple, has improved the treatment effeciency of transport service.Owing to adopt a kind of special frame encapsulation format, promptly before the MAC of standard ethernet Frame head, encapsulate one deck MAC head again, in order to recognition purpose ring network node address and the source of transmission ring network node address, and the type numerical value by wherein is designated two-layer MAC head carrying looped network, make each node device not need other ancillary techniques can correctly discern the business datum that processing need transmit, reduced network cost.

Description of drawings

Fig. 1 is the one-tenth ring structure schematic diagram of the ring-like Ethernet of the present invention;

Fig. 2 is the realization flow figure of the inventive method;

Fig. 3 is the protection switchover mode schematic diagram of the ring-like Ethernet of the present invention.

Embodiment

Core of the present invention is to adopt RPR to become the method for ring to make Ethernet Cheng Huan; make up ring-like Ethernet; and adopt two-layer ethernet mac (medium access control) address encapsulation format to realize the forwarding of two layers of ethernet data frame, make this ring-like Ethernet have topological automatic discovering and fault detect, function such as protection fast simultaneously.

In order to make present technique field personnel understand the present invention program better, the present invention is described in further detail below in conjunction with drawings and embodiments.

The topological structure of this ring-like Ethernet is as shown in Figure 1: comprise a plurality of apparatus for network node R1, R2, R3, R4, adopt twin nuclei, adjacent apparatus for network node connects by a pair of reverse physical link, is used for the business datum between transport network node.Need to send to by each apparatus for network node that this is online through the business datum of this ethernet ring network transmission, through connecting the transmission of the physical link between the apparatus for network node, by corresponding network node equipment its reception is sent in the looped network network equipment in addition again.Each apparatus for network node receives and is connected respectively on the different adjacent node equipment with the different physical ports that send same looped network Frame, and this transmission and receive mode with common ethernet device is different.For Ethernet, the reception of data and transmission are the same physical ports that is connected to same equipment, rather than two different physical ports of two equipment.

For the ring-like Ethernet of the present invention, two layer services of its physical link carrying are the looped network Frame of a two-layer media access control MAC encapsulation format.Before the business datum of each apparatus for network node ring on sending the ethernet data frame that receives is packaged into the looped network Frame with two-layer MAC encapsulation format; The outer MAC head of the described looped network Frame that will receive before the business datum of ring under sending is peeled off.

This ring can be realized topological automatic discovering and fault detection capability.Employing has the ethernet data frame of special ethernet type sign as the topological data frame, and its source address is for sending node, and destination address is a multicast address.After the topological data frame is dealt into each node, this node adds the topology information of oneself in the topological data frame, such as MAC Address, and recomputate CRC (cyclic redundancy check (CRC)), after such Frame was got back to the source sending node, the source sending node just can obtain the topological diagram of whole looped network.

Equally, the ethernet data frame that employing has special identifier detects Frame as ring network fault, each node periodically sends ring network fault to adjacent node and detects Frame on the ring, the topological diagram information that comprises whole looped network in this Frame judges on the ring according to the information that adjacent node returns whether fault has taken place.

At first the encapsulation format of ethernet data frame is done simple declaration below.

The encapsulation format of ethernet data frame is as shown in table 1 below:

Table 1:

Purpose MAC address	Source MAC	Type/length	VLAN	Type/length	Static load	Check byte
							Purpose MAC address	Send the MAC Address of source port	8100	XX?XX	XX?XX	00	XX?XX
6	6	2	2	2	42～ 1500	4

Two type/length field are arranged in last table, the type of VLAN front is the type numerical value of two fixing bytes, the type of expression VLAN, the type numerical value of back is then according to the content difference of static load, different type numerical value is arranged, and is IPV4 such as the hypothesis static load, and then type numerical value is 0806, if be IPV6, then be another one numerical value.

In order to realize the topology auto-discovery function of network, the Topology Discovery Frame adopts MAC encapsulation format of individual layer, relies on special EtherType (ethernet type) numerical value (being defined as 0811) to discern, i.e. type/the length field on the 4th hurdle in the table 2.

The encapsulation format of Topology Discovery Frame is as shown in table 2 below:

Table 2:

Purpose MAC address	Source MAC	Type/length	VLAN	Type/length	Static load	Check byte
							Multicast MAC address	Send the MAC Address of source node	8100	XX?XX	0811	00	XX?XX
6	6	2	2	2	42～ 1500	4

The Topology Discovery Frame is dealt into after each node, and each node adds the MAC Address (and recomputating CRC) of oneself in the back, and when such Frame was got back to the source sending node, the source sending node just can obtain the topological diagram of whole looped network.

It is as shown in table 3 below that node adds form on the ring of Topology Discovery Frame:

Table 3:

Purpose MAC address	MAC address, source	Type/length	VLAN	Type/length	Node number	Node address	Node capacity	...	Node number	Node address	Node capacity	Check byte
													Multicast MAC address	Send the MAC address of source node	8100	XX XX	0811	01	XX?XX?XX XX?XX?XX			n	XX?XX?XX XX?XX?XX		XX XX
6	6	2	2	2	1	6			1	6		4

By such Topology Discovery process, each node on the ring can form the topological diagram of oneself, and this topological diagram comprises on the left and right sides neighbours, ring of ring ID (comprising this value in the numerical value of VLAN), this node, this node ability of node on the distance between the node and this node, the ring (as fair algorithm, switch ability) or the like.Had after the topological diagram, each node can carry out the forwarding of business datum according to this topological diagram.

In order to realize encircling professional correct transmission, the present invention adopts two-layer ethernet mac address encapsulation header to encapsulate the ethernet data frame that ring is gone up transmission.

Ring-like ethernet data frame encapsulation format based on two layer MAC address heads among the present invention is as shown in table 4 below:

Table 4:

Purpose MAC address	MAC address, source	Type/length	VLAN	Type/length	Purpose MAC address	MAC address, source	Type/length	VLAN	Type/length	Static load	Check byte
												The purpose ring network node address	Transmission source ring network node address	8100	XX XX	0810	Destination host MAC address	Send source host MAC address	8100	XX XX	XX XX	00	XX XX
6	6	2	2	2	6	6	2	2	2	42～ 1500	4

Wherein, front one deck MAC head is specialized in looped network and used, and is only effective on ring, adds in last ring, removing in the ring down.One deck MAC head of back is the MAC head of original Frame, is all remaining unchanged in the ring up and down.

In the superincumbent data frame format, it is two-layer MAC head carrying looped network that the back type numerical value in the MAC head of use front is distinguished, and defining its numerical value is 0810.And first type numerical value is original fixed numbers 8100.Use VLAN ID (VLAN ID) to indicate that interior ring is transmitted or outer shroud is transmitted, promptly make the sign of ring ID.Still use the priority among the VLAN to make Priority flag.CFI (Canonical Format Indicator, conventional form Warning Mark, a bit among the VLAN) indication of 1 bit in the definition of Ethernet head is used to be masked as Flooding (inundation) sign.If promptly this is masked as " 1 ", representing this Frame is the unicast data frames of purpose MAC the unknown, need make Flooding on ring and handle.

Describe the flow process of utilizing this ring-like Ethernet to transmit customer service in detail below in conjunction with flow process shown in Figure 2, may further comprise the steps:

Step 201: each node adopts the Topology Discovery Frame of special ethernet type sign to collect ring-like Ethernet topological structure on the ring, sets up network topological diagram separately.

The encapsulation format of Topology Discovery Frame is existing in front to be described in detail, and it is identical with the standard ethernet data frame format, adopts the encapsulation of individual layer MAC head, just relies on special EtherType numerical value (being defined as 0811) to identify.

Is target MAC (Media Access Control) address how multicast mac address (is determined in this Topology Discovery Frame?), source MAC is the MAC Address of the source node of this Topology Discovery Frame of transmission.Each node regularly adopts the multicast mode to send it to destination node, receive that the node of this Topology Discovery Frame adds the mac address information of oneself in this Topology Discovery Frame, and calculation check value again, keep original multicast mac address, send it to destination node then.Like this, this Topology Discovery Frame comes back to source node after encircling the forwarding of going up all nodes, the Topology Discovery Frame of this moment has comprised the upward information of all nodes of ring, and source node can be set up the network topological diagram of oneself according to the mac address information of each node in this Topology Discovery Frame.This topological diagram comprises: the information such as ability of each node on the distance on the left and right sides neighbors of ring ID, this node, this node, the ring between node and this node, the ring.

By this topological automatic discovering process, can make Ethernet group ring not need to carry out structural arrangements, self-adapting network changes of topology structure.

Step 202: at the service source node, with the outer MAC Address head that increases for ring-like Ethernet identification of ethernet data frame, ring-like Ethernet in the scheduling.

After last each node of ring has been set up the network topological diagram of oneself, promptly know to lay oneself open on some rings, and know the left and right sides neighbors of oneself.

After this node is received an ethernet data frame that upward encircles, according to this network topological diagram, know the next destination node that it will be transmitted, at this moment, in order to make the last node of ring can discern this Frame is the looped network Frame that will transmit on looped network, the ethernet data frame skin of receiving is increased one deck MAC head again come it is encapsulated.Target MAC (Media Access Control) address in this MAC head extends this as the target MAC (Media Access Control) address of looped network Frame, and the type of the concrete Frame of transmitting is as required filled in.Such as, for two layers of unknown unicast Frame, extend this as the target MAC (Media Access Control) address of unknown unicast; For two layers of known unicast Frame, extend this as the MAC Address of purpose link point; For the L 2 broadcast Frame, extend this as the L 2 broadcast MAC Address; For the Layer 2 Multicast Frame, extend this as Layer 2 Multicast MAC Address etc.Source MAC extends this as the MAC Address of this node, ethernet type extends this as ring and goes up the particular values (as 0810) that node uses, VLAN priority in VLAN (VLAN) territory extends this as priority on the ring of this ethernet data frame, the VLAN sign extends this as the ring ID that need send to, and identifies the ethernet data frame that needs inundation with CFI (conventional form Warning Mark).Such as, for the unknown unicast Frame,, therefore, CFI need be made as " 1 " owing to do not know the destination node MAC Address of this Frame, expression need be carried out inundation.

When determining on the ring of ethernet data frame priority, can determine according to the priority mapping in the looped network Frame internal layer MAC head; Also can determine according to the ACL (access control list) or QOS (service quality) specification of looped network Frame internal layer static load.Go into physical port, VLAN and VLAN priority, source and/or target MAC (Media Access Control) address, source and/or purpose IP address, source and or purpose TCP/UDP port, DSCP numerical value, protocol type etc. such as, ethernet data frame.

After ethernet data frame encapsulation is finished, with it as the looped network Frame, ring-like Ethernet in the scheduling.

Describe in detail based on the encapsulation format of the looped network Frame of two-layer MAC head is existing in front, do not repeat them here.

Step 203: each node is transmitted the ethernet data frame that has added the MAC head according to the network topological diagram of its foundation on the ring.

After each node receives the looped network Frame that has two-layer MAC head,, determine the type of this looped network Frame according to sign of the Flooding (inundation) in this Frame frame head and special EtherType (ethernet type) numerical value.

The present technique field personnel know, the following several situations of the type of grouped data: unknown unicast Frame, known unicast Frame, multicast packet frame, broadcast data frame.Its repeating process of data of different types frame is similar, mostly comprises: the go up ring, ring of Frame are gone up and are transmitted, plurality of processes such as peel off from ring again, but destination node difference that need forwarding.

Such as, need two kinds of operations for the unknown unicast Frame: a kind of is to continue to send it to sending direction according to the network topological diagram that this node is set up to carry out Flooding, another kind is that this Frame is peeled off out from outer MAC head encapsulation, and then carries out two or three layers forwarding.And,, then only needing a kind of operation if this node is not its destination node for the known unicast Frame: the network topological diagram of setting up according to this node continues to mail to the sending direction that this ring is gone up physical port with former Frame; If this node is its destination node, then also only need a kind of operation: this Frame is peeled off out, and then carry out two or three layers forwarding from outer MAC head encapsulation.

In the repeating process that carries out the looped network Frame, each node also needs to carry out simultaneously the MAC address learning process.Source MAC in the looped network Frame internal layer MAC head is learnt under the source MAC in the outer MAC head, consider under some applicable cases, from encircling certain source node to certain destination node, when transmission is carried by different rim bearings with the business that receives, each node need be known the forwarding situation of each business on two rings of the different directions of ring-like Ethernet, therefore also needs with the MAC address learning on two rings of this ring-like Ethernet together.

Step 204:, the looped network Frame is peeled off ring-like Ethernet at the business purpose node.

After the looped network Frame was forwarded to destination node, destination node was peeled off it according to information such as the EtherType numerical value in this Frame, Flooding sign, ring ID sign, destination node MAC Address signs.In stripping process, also to carry out the study of MAC Address, the source MAC in the internal layer MAC head of looped network Frame is learnt under the source MAC in the outer MAC head.

Be described in detail respectively at the transmission course of ring-like Ethernet under the different situations below business data frame.

1. on ring-like Ethernet, carry out the forwarding of two layers of unknown unicast Frame

The forwarding of this Frame relates on the unicast data frames Flooding (inundation) on ring, the ring, plurality of processes such as peels off from encircling.

(1) going up of unknown unicast Frame encircled

After node receives the unknown unicast Frame that encircles in the preparation in last central port on the ring,, need to do following special processing owing to do not know the destination node MAC Address of this Frame:

Purpose MAC in the outer MAC head is extended this as the target MAC (Media Access Control) address of unknown unicast, and source MAC extends this as the MAC Address of this node itself;

EtherType extends this as 0810, is masked as ring and goes up the particular values that node uses, and represents this layer MAC back to also have other one deck MAC head;

VLAN (VLAN) priority (3 bits) is filled in priority on the ring of this Frame, can obtain according to the priority mapping in the internal layer MAC head, or obtain according to the ACL or QOS (service quality) specification of internal layer static load, obtain such as go into physical port, VLAN and VLAN priority, source and/or target MAC (Media Access Control) address, source and/or purpose IP address, source and/or purpose TCP/UDP (transmission control protocol/User Datagram Protocol) port, DSCP (differentiated services code points) numerical value, protocol type etc. according to Frame.

Because CFI (the Canonical Format Indicator of 1 bit in the definition of Ethernet head, conventional form Warning Mark) indication is used to be masked as the Flooding sign, so this target MAC (Media Access Control) address is that the Flooding sign of unknown unicast Frame is effective, is " 1 ".

VLAN ID (12 bit) fills in according to ring ID, and promptly which ring this unknown unicast Frame need be dealt on, just extends this as the VLAN ID of which ring.Determine the purpose ring ID of this Frame, can use top ACL classification specification equally.Such as the unknown unicast Frame of certain VLAN=100 is transmitted at interior ring, and the unknown unicast Frame of another one VLAN=200 is transmitted at outer shroud.

This unknown unicast Frame is sent to ring and goes up other node to after encircling upward.

(2) the Flooding process on the ring

After node receives this Frame from the receive direction of a port on the ring, need do this Frame is carried out following processing:

(a) judge whether it is two layers of unknown unicast Frame

According to sign of the Flooding in this Frame frame head and special EtherType numerical value, be confirmed to be one two layers unknown unicast Frame.Its copy portion is encircled down, and former Frame is continued to mail to the sending direction that this ring is gone up physical port.As a rule, for encircling the MAC Address that goes up node, a high position is identical.Such as the ring for one 256 node, the MAC Address of high 40 bits is identical, has only the least-significant byte difference.

(b) forwarding of Frame is handled

For the ring upper port, the Frame that a physical port receive direction need be received is from the sending direction transmission of this physical port.This is different with the forwarding of common Ethernet, in common Ethernet repeating process, does not allow same Frame to be sent from the physical port that receives it, in order to avoid form two layers of circulation circuit.But the realization in this function and Wireless Switch (wireless session) function requires similar, in the application of Wireless Switch, because not making Layer 2 data, do not transmit AP (access point), so need all Layer 2 data forwarding capabilitys in switch, to finish.And common interface has only an Ethernet interface between switch and the AP, so switch be need support user's intercommunication below the same AP time, and switch just need send back to this interface again with the Frame that this interface comes.

For the ring upper port, need do two kinds of operations for the Frame of Flooding, one is continued to send to sending direction with this Frame and carries out Flooding, another one is that this Frame is peeled off out (being the equal of to terminate) from two-layer MAC head encapsulation from tunnel encapsulation, and then carries out two or three layers of forwarding.

(c) study of MAC Address

For the ring upper port, also need to do the study of MAC Address, with the source MAC in the internal layer MAC head, learn under the source MAC in the outer MAC head.It should be noted that each node needs and will put together in the MAC address learning result on two rings on the ring-like Ethernet, because under some looped network applicable cases, from certain source link point (as link point 1) to certain purpose link point (as link point 5), sending with receiving is on different rings, carry by outer shroud such as the business that is dealt into link point 5 from link point 1, and the business that is dealt into link point 1 from link point 5 is carried by interior rim bearing.If with the MAC address learning on two rings to together, then each other study forever less than MAC Address, all business will be on ring Flooding, the bandwidth of waste looped network.

When study, have only two territories, one is the source MAC of two layer services, another one is the MAC Address of ring node ID.And the physical port address that needs when not having common Ethernet to transmit, this territory is encircled node ID and is replaced.That is to say that the process of study is the learning process of similar VPLS (virtual private LAN segment), certain source MAC is learnt below the Site of certain VPN (Virtual Private Network).

(3) the unknown unicast Frame peels off

This unknown unicast Frame is forwarded back after the source node, and source node is peeled off this packet according to EtherType numerical value, Follding sign, ring ID sign and the source node MAC Address flag information of this Frame.That is to say, if the Flooding Frame of two layers of looped network, and its ring ID sign is identical with the ring ID sign that receives this Frame, and the source node MAC Address equals the MAC Address of this node, then this packet to be peeled off, send it to down the port of ring then at this node.

It should be noted that and to judge ring ID sign; because when the protection of looped network is switched; business on outer shroud may not arrive the appointment destination node; deliver to destination node again behind the ring at this time it just need be switched to; may need to pass through source node in this process, just can not be stripped from this time.Because the ring ID sign that its ring ID sign is received with it does not meet.

2. on ring-like Ethernet, carry out the forwarding of known two layers of unicast data frames

Still relate to repeating process on ring, the ring, plurality of processes such as peel off from destination node again for the Frame handling process of known unicast.

(1) going up of known unicast Frame encircled

After node receives the known unicast Frame that encircles in the preparation in last central port on the ring, purpose MAC in the outer MAC head (only for looped network MAC head use) is extended this as the MAC Address of purpose link point, and source MAC extends this as the MAC Address of this node itself.

EtherType extends this as 0810, is masked as ring and goes up the particular values that node uses, and also has other one deck MAC head after representing this layer MAC head;

VLAN priority (3 bits) extends this as priority on the ring of this Frame, this priority can obtain according to the priority mapping in the internal layer MAC head, or obtain according to the ACL or the QOS specification of internal layer static load, such as according to Frame go into physical port, VLAN and VLAN priority, source and/or target MAC (Media Access Control) address, source and/or purpose IP address, source and or purpose TCP/UDP port, DSCP numerical value, protocol type etc. obtain.

Because the CFI indication of 1 bit is used to be masked as the Flooding sign in the definition of Ethernet head.So it is invalid that this target MAC (Media Access Control) address is that the Flooding of known unicast data frames is masked as, and is " 0 ".

VLAN ID (12 bit) fills in according to ring ID, and promptly which ring this known unicast need be dealt on, just extends this as the VLAN ID of which ring.Determine the purpose ring ID of this Frame, can use top ACL classification specification equally.Such as, the known unicast Frame of certain VLAN=100 is transmitted at interior ring, and the known unicast Frame of another one VLAN=200 is transmitted at outer shroud.

Behind the ring, be sent to ring and go up other node on this known unicast Frame.

(2) repeating process on the ring

After node receives this Frame from the receive direction of a port on the ring,, be confirmed to be one two layers known unicast Frame according to sign of the Flooding in this Frame frame head and special EtherType numerical value.Therefore only need to judge whether destination node is this node, if not, just former Frame need be continued to mail to the sending direction that this ring is gone up the physical port of this node.

For the ring upper port, also need to do the study of MAC Address, with the source MAC in the internal layer MAC head, learn under the source MAC in the outer MAC head.

(3) the known unicast Frame peels off

After this known unicast Frame was forwarded to destination node, destination node was peeled off according to EtherType numerical value, Flooding sign, ring ID sign and the destination node MAC Address sign of this Frame.That is to say that if the known unicast Frame of two layers of looped network, and its destination node MAC Address equals the MAC Address of this node, so just needs this packet is peeled off from ring, sends it to down the port that encircles then.

For the ring upper port, also need to do the study of MAC Address, with the source MAC in the internal layer MAC head, learn under the source MAC in the outer MAC head.

3. on ring, carry out the forwarding of L 2 broadcast Frame

Relate to repeating process on ring, the ring equally, plurality of processes such as peel off from destination node again for the Frame handling process of L 2 broadcast.

(1) going up of L 2 broadcast Frame encircled

After node receives the L 2 broadcast Frame that encircles in the preparation in last central port on the ring, target MAC (Media Access Control) address in the outer MAC head (only using for looped network MAC head) is extended this as the L 2 broadcast MAC Address, and source MAC extends this as the MAC Address of this node itself.

EtherType extends this as 0810, is masked as ring and goes up the particular values that node uses, and represents this layer MAC back to also have other one deck MAC head.

VLAN priority (3 bits) extends this as priority on the ring of this Frame, this priority can obtain according to the priority mapping in the internal layer MAC head, or obtain according to the ACL or the QOS specification of internal layer static load, obtain such as go into physical port, VLAN and VLAN priority, source and/or target MAC (Media Access Control) address, source and/or purpose IP address, source and/or purpose TCP/UDP port, DSCP numerical value, protocol type etc. according to Frame.

Because the CFI of 1 bit indication is used to be masked as the Flooding sign in the Ethernet head definition, be masked as invalidly so this target MAC (Media Access Control) address is the Flooding of L 2 broadcast Frame, be " 0 ".

VLAN ID (12 bit) fills in according to ring ID, this known unicast need be dealt on which ring, just extends this as the VLAN ID of which ring.Determine the purpose ring ID of this Frame, can use top ACL classification specification equally.Such as, the L 2 broadcast Frame of certain VLAN=100 is transmitted at interior ring, and with the L 2 broadcast Frame of another one VLAN=200 in outer shroud forwarding etc.

This L 2 broadcast Frame is sent to ring and goes up other node to after encircling upward.

(2) repeating process on the ring

After node receives this Frame from the receive direction of a port on the ring,, be confirmed to be a L 2 broadcast Frame according to the broadcasting MAC Address in this Frame frame head, Flooding sign and special EtherType numerical value.Therefore its copy portion need be encircled down, and former Frame is continued to mail to the sending direction that this ring is gone up this node physical port.For the processing procedure of Frame, identical with the processing procedure of introducing previously for unknown unicast, do not repeat them here.

For the ring upper port, also need to do the study of MAC Address, with the source MAC in the internal layer MAC head, learn below the source MAC in the outer MAC head.

(3) the L 2 broadcast Frame peels off

After this L 2 broadcast Frame was forwarded back source node, source node was peeled off according to EtherType numerical value, Follding sign, ring ID sign and the source node MAC Address sign of this Frame.That is to say, if the L 2 broadcast Frame of two layers of looped network, and its ring ID sign is identical with the ring ID sign that receives this Frame, and the source node MAC Address equals the MAC Address of this node, then this packet is peeled off, sent it to down the port of ring then.

It should be noted that and to judge ring ID sign; because when the protection of looped network is switched; business on outer shroud may not arrive the appointment destination node; at this moment deliver to destination node again behind the ring in just it need being switched to; may need to pass through source node in this process, just can not peel off this packet this moment.Because the ring that its ring ID sign is received with it does not meet.This point is identical with the handling process of two layers of unknown unicast.

4. on ring, carry out the forwarding of Layer 2 Multicast Frame

Relate to repeating process on ring, the ring equally, plurality of processes such as peel off from destination node again for the Frame handling process of Layer 2 Multicast.

(1) going up of Layer 2 Multicast Frame encircled

After node receives the Layer 2 Multicast Frame that encircles in the preparation in last central port on the ring, the purpose MAC in the outer MAC head (only using for looped network MAC head) is extended this as the Layer 2 Multicast MAC Address, and source MAC extends this as the MAC Address of this node itself.

EtherType extends this as 0810, is masked as ring and goes up the particular values that node uses, and represents this layer MAC back to also have other one deck MAC head, arrived destination node after, destination node sends to down this Frame the port that encircles after needing this layer MAC head peeled off again.

VLAN priority (3 bits) extends this as priority on the ring of this Frame, this priority can obtain according to the priority mapping in the internal layer MAC head, or obtain according to the ACL or the QOS specification of internal layer static load, obtain such as go into physical port, VLAN and VLAN priority, source and/or target MAC (Media Access Control) address, source and/or purpose IP address, source and/or purpose TCP/UDP port, DSCP numerical value, protocol type etc. according to Frame.

Because the CFI indication of 1 bit is used to be masked as the Flooding sign in the definition of Ethernet head.So it is invalid that this target MAC (Media Access Control) address is that the Flooding of L 2 broadcast Frame is masked as, and is " 0 ".

VLAN ID (12 bit) fills in according to ring ID, promptly needs which ring this known unicast is dealt on, just extends this as the VLAN ID of which ring.Determine the purpose ring ID of this Frame, can use top ACL classification specification equally.Such as, the Layer 2 Multicast Frame of certain VLAN=100 is transmitted at interior ring, and with the Layer 2 Multicast Frame of another one VLAN=200 in outer shroud forwarding etc.

This Layer 2 Multicast Frame is sent to ring and goes up other node to after encircling upward.

(2) repeating process on the ring

After node receives this Frame from the receive direction of a port on the ring,, be confirmed to be a Layer 2 Multicast Frame according to the multicast mac address in this Frame frame head, Flooding sign and special EtherType numerical value.

If this node has joined this multicast group (whether node joins certain multicast group, is determined by upper-layer protocol software), then need a ring down of its copy, and former Frame is continued to mail to the sending direction that this ring is gone up this node physical port.This moment is for the processing procedure of Frame, and is identical with the processing procedure of introducing previously for unknown unicast or L 2 broadcast.

If this node does not join this multicast group, then former Frame is continued to mail to the sending direction that this ring is gone up physical port.This moment is for the processing procedure of this Frame, and is identical with the processing procedure of introducing previously for the known unicast Frame.

For the ring upper port, also need to carry out the study of MAC Address, with the source MAC in the internal layer MAC head, learn under the source MAC in the outer MAC head.

(3) the Layer 2 Multicast Frame peels off

After this Layer 2 Multicast Frame was forwarded back source node, source node was peeled off it according to EtherType numerical value, Flooding sign, ring ID sign and the source node MAC Address sign of this Frame.That is to say that if the Layer 2 Multicast Frame of two layers of looped network, and its ring ID sign and the ring ID that receives this Frame indicate identically, and the source node MAC Address equals the MAC Address of this node, then this packet peeled off.

So only multicast packet being wrapped in source node peels off, main cause has two: the one, in the network application of reality, it mainly is to transmit the IPTV program at operator in Metro Ethernet that the looped network of Layer 2 Multicast and broadcasting is used, be actually this moment and multicast need be handled as broadcasting, to satisfy main application.The 2nd, if adopt with multicast group method that destination node is peeled off in the end, so because the last link point of multicast group is different, just need many multicast tree at not the same ring source node be set separately at each multicast group, though the information of this source node has in the data frame head, but along with ring is gone up increasing of interstitial content, a lot of list items (such as the looped network at 256 nodes, the number of multicast tree may be original 256 times) need be set, lose more than gain.

It should be noted that and to judge ring ID sign when carrying out the peeling off of Frame; because when the protection of looped network is switched; business on outer shroud may not arrive the appointment destination node; need be switched to it this moment be sent to destination node again behind the ring in; in this process, may need to pass through source node; just can not peel off it this moment, because the ring that its ring ID sign is received with it does not meet.This point is identical with the handling process of two layers of unknown unicast.

In order to realize the quick protection of ring-like Ethernet; carry out the ring network fault detection by encircling the topological checking data frame that timed sending adopts special ethernet type to identify between adjacent node in the present invention, rather than adopt a home site that has now among the EAPS to detect the method for the malfunction of whole looped network.

Topological checking data frame that adopts among the present invention and the Topology Discovery Frame of introducing previously are similar, adopt MAC encapsulation format of individual layer, and be as shown in table 5 below.This Frame is same to rely on special EtherType numerical value (being defined as 0811) to discern.

Table 5:

Purpose MAC address	Source MAC	Type/length	VLAN	Type/length	Subtype	Static load	Check byte
								Multicast MAC address	Send the MAC Address of source node	8100	XX?XX	0811	0010	00	XX?XX
6	6	2	2	2	2	40	4

Subtype is the subtype Frame of expression looped network, as topology discovery, fair algorithm or the like.

After last each node of ring is set up the network topological diagram of oneself, then regularly send above topology checking data frame to adjacent node, in the static load territory of this Frame, put into topological diagram check information (as the verification of 4 bytes and etc.), if check and do not change, just represent not variation of topology; If change, illustrate that then fault has taken place adjacent node, need to send fault data frame notice the whole network node this moment.

For ability is switched in the protection that strengthens ring-like Ethernet, the ring-like Ethernet of the present invention provides Wrap (loopback) protection to switch and Steer (source routing) protection switch function.When breaking down, carry out the Wrap protection by the node that breaks down at first earlier and switch on ring, after the status data of each node was restrained again and be stable, all nodes carried out Steer again and protect and switch on the ring.

Fig. 3 shows the schematic diagram that ring-like Ethernet protection is switched:

Last figure is the normal flow before the fault, and the R1 node is walked outer shroud to the R3 node, and the path is R1-R4-R3;

Middle figure is a Wrap protected mode after the fault, after breaking down between R4 node and the R3 node, carries out loopback by link on the node at fault two ends, and data path is also at this loopback, and total path is R1-R4-R1-R2-R3;

Figure below is a Steer protected mode after the fault, and the data traffic from the R1 node to the R4 node changes takes a shortcut, and walks the another one ring and arrives destination node, and the path is R1-R2-R3.

Because Wrap just relates to the switching action of a node, so speed is very fast.When Wrap switches, require the switching node will be in the transmission business on the ring, be switched on the another one ring and send.This work of switching is done at the MAC layer, and the transmission that is about to a MAC interface is docked with the reception of another one MAC interface.

When switching, change the sign of ring ID simultaneously, change original transmission sign (using VLAN ID to indicate) on outer shroud into new VLAN numerical value (as VLAN=3) as VLAN=1.Change original transmission sign (using VLAN ID to indicate) on interior ring into new VLAN numerical value (as VLAN=4) as VLAN=2.Such purpose is in order to make data flow pass through source node.Loopback website in the another one opposite end is changeed back again again, for example changes VLAN=3 into VLAN=1, VLAN=4 is remodified be VLAN=2.

The Steer guard method of looped network is after ring is gone up all nodes and all obtained ring-network topology and change, according to new topology, to readjust the professional route that sends and the flow of transmission.

The present invention when ring-like ethernet link breaks down, starts Loopback Mode protection, non-interrupting service in conjunction with these two kinds of switchover modes advantage separately immediately; After the various status datas (topology information etc.) of each node are restrained again and settled out, switch to the source routing mode, so that save bandwidth.Thereby can reach best protection effect and bandwidth availability ratio.

Though described the present invention by embodiment, those of ordinary skills know, the present invention has many distortion and variation and do not break away from spirit of the present invention, wish that appended claim comprises these distortion and variation and do not break away from spirit of the present invention.

Claims (12)

1, a kind of ring-like Ethernet, it is characterized in that, comprise: a plurality of apparatus for network node, be used for business datum sent on the ring-like Ethernet or from ring-like Ethernet and receive business datum, each apparatus for network node receives and is connected respectively on the different adjacent node equipment with the different physical ports that send same looped network Frame; Adjacent apparatus for network node connects by a pair of reverse physical link, is used for the business datum between transport network node; Two layer services of described physical link carrying are the looped network Frame of a two-layer media access control MAC encapsulation format.

2, ring-like Ethernet according to claim 1 is characterized in that, before the business datum of each apparatus for network node ring on sending the ethernet data frame that receives is packaged into the looped network Frame with two-layer MAC encapsulation format.

3, ring-like Ethernet according to claim 1 is characterized in that, the outer MAC head of the described looped network Frame that will receive before the business datum of each apparatus for network node ring under sending is peeled off.

4, ring-like Ethernet according to claim 1, it is characterized in that, each apparatus for network node adopts the ethernet data frame with special ethernet type sign to realize encircling upper topology and finds automatically and fault detect that described ethernet data frame with special ethernet type sign is an individual layer MAC encapsulation format.

5, based on the service bearer implementation method of the described ring-like Ethernet of claim 1, it is characterized in that, comprising:

Each node adopts the Topology Discovery Frame of special ethernet type sign to collect ring-like Ethernet topological structure on A, the ring, sets up network topological diagram separately;

B, at the service source node, ethernet data frame is encapsulated as the looped network Frame, and it is served ring-like Ethernet;

Each node is transmitted described looped network Frame according to the network topological diagram of its foundation on C, the ring;

D, at the business purpose node, described looped network Frame is peeled off ring-like Ethernet.

6, method according to claim 5 is characterized in that, described method further comprises step:

The topological checking data frame that timed sending adopts special ethernet type to identify between adjacent node on E, the ring carries out ring network fault and detects;

F, the node that detects fault are gone up every other node to ring and are sent the fault data frame, and fault message notice ring is gone up every other node.

7, method according to claim 5 is characterized in that, described method further comprises step:

G, when breaking down, carry out loopback Wrap protection by the node that breaks down earlier and switches on ring, after the status data of each node was restrained again and be stable, all nodes carried out source routing Steer again and protect and switch on the ring.

8, according to claim 5 or 6 or 7 described methods, it is characterized in that described steps A comprises:

A1, each node regularly adopt the multicast mode to send described Topology Discovery Frame;

A2, receive that the node of described Topology Discovery Frame adds the mac address information of oneself in this Topology Discovery Frame;

A3, receive the Topology Discovery Frame that oneself sends when the source sending node after, set up the network topological diagram of oneself according to the media access control MAC address information of each node in this Topology Discovery Frame.

9, according to claim 5 or 6 or 7 described methods, it is characterized in that, in described step B, in the following manner ethernet data frame be encapsulated as the looped network Frame:

At the outer MAC Address head that increases for ring-like Ethernet identification of ethernet data frame, target MAC (Media Access Control) address in the MAC Address head extends this as the target MAC (Media Access Control) address of described looped network Frame, source MAC extends this as the MAC Address of this node, ethernet type extends this as ring and goes up the particular values that node uses, virtual LAN VLAN priority extends this as priority on the ring of this ethernet data frame, the VLAN sign extends this as the ring ID that need send to, and identifies the ethernet data frame that needs inundation with conventional form Warning Mark CFI.

10, method according to claim 9 is characterized in that, in the following manner priority on the ring of definite described ethernet data frame:

Determine according to the priority mapping in the looped network Frame internal layer MAC head; Perhaps

Access control list ACL or service quality QOS specification according to looped network Frame internal layer static load are determined.

11, according to claim 5 or 6 or 7 described methods, it is characterized in that described step C comprises:

C1, this node are judged the type of the looped network Frame that receives;

C2, the network topological diagram of setting up according to described type and this node are transmitted this looped network Frame;

C3, carry out MAC address learning, be specially: the source MAC in the looped network Frame internal layer MAC head is learnt under the source MAC in the outer MAC head, and the MAC address learning on will two rings of this ring-like Ethernet together.

12, according to claim 5 or 6 or 7 described methods, it is characterized in that described step D further comprises:

When the looped network Frame is peeled off, the source MAC in the internal layer MAC head of looped network Frame is learnt under the source MAC in the outer MAC head.