CN100463381C - Method for optical transmission ring net reliable switch - Google Patents

Abstract

This invention is relative to the processing technology for local fault in the optical ring network. According to the feature of multi section protection switching when detecting error code in the optical fiber signal, makes the transmission net element determine the corrective method for retransmission after processing the information of target net element and source net element held in K1, K2 byte. It provides reliable switching method in the optical ring network, includes following steps: the current net element transmits the K1,K2 byte received from the relative direction of the direction generating long term error code to the above error code direction; the above current net element exchanges the target net element ID held by K1 byte received from the above relative direction for the source net element ID held by K2 byte, then transmits the K1,K2 bytes rebuilt to the above relative direction. The method can promote probability of correctly delivering the protection switching signaling.

Description

The method that the optical transmission ring network is reliably switched

Technical fieldThe present invention relates to optical transport technology, particularly the treatment technology of optical transmission ring network local fault.

Background technologyMultiplex section protection exchanging is to recover professional a kind of important method after the optical transmission ring network breaks down rapidly.Usually, after transmission looped network broke down, the protection of transmission equipment was switched software and is recovered because the transport service that fault is interrupted by the bridge joint measure of switching.Bridge joint is to send professional a kind of measure simultaneously to Working service passage and protection passage; Switch and be meant, originally receive the measure that professional mode is changed into the business that receives from the protection passage from the Working service passage receiving when professional.G.841, ITU-T has advised stipulating the detailed rules and regulations that multiplex section protection exchanging is realized, regulation transmits the multiplex section protection exchanging signaling with MSOH K1 and K2 byte simultaneously.Wherein the K1 byte transmits the sign of request coding and purpose network element, and the K2 byte transmits sign, line of apsides sign and the conditional code of source network element.In professional transmission course, because factors such as equipment, environment, it is inevitable producing error code.K1 and K2 error code can influence bridge joint and switch the normal foundation of measure, even the situation frequently setting up and cancel can occur, promptly switch vibration, and transport service also can be subjected to very macrolesion.

Generally, K1 at random, K2 error code can be got rid of by filtering rule.But for the long-time error code that causes owing to factors such as optical fiber are aging, error code filters and can not finally deal with problems.In this case, still there is the hidden danger of switching frequent foundation and cancelling.

Fig. 1 is the transmission looped network that adopts multiplex section protection.Under normal conditions, C-for example〉D direction optical fiber breaks down, and after D detects alarm, produces ring bridge joint switching request, by producing MSOH K1, K2 through D-〉A-〉B-〉C and D-〉C two paths are sent to C.C receives D-〉produce echo message after the request transmitted of C path, by K1, K2 through C-B-A-the D path is sent to D.Receiving D-〉A-〉B-〉after the request transmitted of C path, C finishes bridge joint and switching action.D receives C-〉B-〉A-〉bridge joint takes place after the response transmitted of D path and switch.So far, because C-〉D direction fiber failure and interrupted service is restored.Simultaneously, D＜-A＜-B＜-the mutual request that transmits in C path and response maintaining the bridge joint of C, D network element and switching.

If aging or other environmental factor of optical fiber appears in the arbitrary section of striding of transmission looped network, then K1, the K2 byte request and the response of can not the reliable transmission protection switching.For example, in Fig. 1, if A-〉optical fiber of B direction is aging or other environmental factor occurs, long-time error code, A-will appear in the signal of Optical Fiber Transmission〉B direction K1 and the K2 byte transmitted also error code will occur.Like this, if catastrophe failures such as disconnected fibre appear in the sections of striding such as BC, CD or DA, then interrupted service can not reliably be recovered.C-for example〉D direction optical fiber breaks down, after D detects alarm, produce ring bridge joint switching request by K1, K2 through D-A-B-C and D-C two paths are sent to C.C receives D-〉produce echo message after the request transmitted of C path, by K1, K2 through C-B-A-the D path is sent to D.Receiving D-〉A-〉B-〉after the request transmitted of C path, C finishes bridge joint and switching action.D receives C-〉B-〉A-〉bridge joint takes place after the response transmitted of D path and switch.But, this moment A-the error code of B direction will influence D through D-A-B-the C path is to the information of C transmission.If C can not receive request, C can not set up bridge joint and switch, and interrupted service can not be restored.Perhaps, if C has set up bridge joint and switching, but in maintaining the process that bridge joint switches, K1, K2 can not normally transmit, and then C will cancel the bridge joint of having set up and switch.Will occur switching vibration so repeatedly, business is subjected to major injury.

No. 99113881 Chinese patent application is provided with the fail safe that different conditions such as switching intermediate state and Wait-to-Restore attitude improves multiplex section protection exchanging by increasing, and effectively prevents monolateral generation of switching.But factors such as aging occur at looped network section optical fiber, when long-time error code appearred in the transmission of K byte, this method can not be avoided protection to switch not starting, or started and switch but switch status is frequently set up and cancelled, and finally can not reliably recover transport service.

U.S. Patent number be 6392992 patent by adopting a kind of optical link behavior control device and method, detect the different stage alarm, possess and prevent the different stage alarm function of vibration repeatedly, thereby improve the reliability that the optical transmission looped network protection is switched.But this invention can not solve K byte transmission when long-time error code occurring, and problems such as can not starting or switch vibration is switched in protection.

From the above, when long-time error code appears in the transmission looped network transmission signals in the prior art, transport service can not obtain reliable protection.

Summary of the inventionThe present invention is for overcoming above-mentioned the deficiencies in the prior art part, characteristics according to the multiplex section protection exchanging agreement, when detecting the fiber-optic signal error code, the method of transmitting after making the transmission network element by the information processing of purpose network element that carries in K1, the K2 byte and source network element again and suitably correcting is judged, improves protection to switch the probability that signaling is correctly sent to; Improve the reliability of multiplex section protection exchanging, thereby reach the purpose of reliably protecting transport service.

Purpose of the present invention can reach like this:

Design, the method that adopts a kind of optical transmission ring network reliably to switch comprise by transmission direction and judge the direction that error code occurs, and form by MSOH K1, the K2 byte that receives to be fit to the K1 that sends, the method for K2 byte; And have following steps:

S4, current network will produce K1, the K2 byte that the relative direction of long-term error code direction receives and transmit to described error code direction;

Behind the source network element ID information exchange of purpose network element ID that the K1 byte that S5, described current network are received described relative direction is carried, send improved MSOH K1, K2 byte to described relative direction with the carrying of K2 byte.

The direction that direction 1 described in the following example links to each other with the adjacent network element with the left and right sides of the direction 2 current transmission network elements of general reference.

Technical scheme of the present invention comprises following flow process:

In the 1st step, the situation of long-time error code appears in current network at direction 1 and direction 2 detection fiber transmission signals.If detect this situation, then changed for the 2nd step over to.

In the 2nd step, current network detects K1, the K2 byte of receiving in direction 1 or direction 2.

In the 3rd step, current network is received suitable K1, K2 byte in direction 1 or direction 2, and enters pass-through state.Otherwise changed for the 1st step over to.

The 4th goes on foot, and enters the current network of pass-through state, if long-term error code situation appears in direction 1, then the K1 that direction 2 is received, K2 byte former state transmit to direction 1.Because direction 1 light signal has long-time error code, the K1 that this direction is received, K2 byte are unreliable, and the K1 that receives from direction 1, K2 byte no longer former state send to direction 2.And direction 2 is received behind the source network element ID information exchange of purpose network element ID information, the carrying of K2 byte of K1 byte carrying as K1, K2 byte to direction 2 transmissions.Processing when long-term error code appears in direction 2 is similar.

Description of drawings

Fig. 1 is two fine transmission looped networks with 4 network elements;

Fig. 2 is the method flow diagram that optical annual network of the present invention is reliably switched

EmbodimentBelow in conjunction with accompanying drawing in detail embodiments of the invention are described in detail.

The method that a kind of optical transmission ring network is reliably switched comprises by transmission direction and judges the direction that error code occurs, and forms by MSOH K1, the K2 byte that receives to be fit to the K1 that sends, the method for K2 byte; And have following steps:

S1, current network detect an adjacent direction and long-time error code occurs;

S2, current network detect K1, the K2 byte that described error code direction and relative direction thereof are received;

S3, current network are received K1, the K2 byte of certain the network element section of striding catastrophe failure in described error code direction and relative direction thereof, and are entered pass-through state.

S4, current network will produce K1, the K2 byte that the relative direction of long-term error code direction receives and transmit to described error code direction;

Behind the source network element ID information exchange of purpose network element ID that the K1 byte that S5, described current network are received described relative direction is carried, send improved MSOH K1, K2 byte to described relative direction with the carrying of K2 byte.

In the practicality, with specific embodiment technical scheme of the present invention is described further in conjunction with the accompanying drawings.

Fig. 1 is the dicyclo optical transport network schematic diagram that local fault is arranged.

Fig. 2 is the flow chart of the reliable reverse method of optical transmission ring network of the present invention.Be the specific implementation process that the method for the invention is adopted in the current network explanation now with network element B.

Step 1: current network is network element B.Network element B is at A-〉the B direction detects long-term error code situation.But be not severe case.

Step 2: network element B detects A-〉B direction and C-〉B direction K1 and the K2 byte received.

Step 3: when catastrophe failure appears in the network element CD section of striding, network element C, D produce protection switching request and echo message respectively, and by K1, K2 D＜-A＜-B＜-transmit alternately in the C path.Network element B is at C-〉B direction or A-〉the B direction enters pass-through state after receiving such K1, K2 byte.

Step 4: network element B is with C-〉K1 that receives of B direction, K2 byte former state be to B-〉transmission of A direction.Simultaneously, with C-〉the purpose network element of the B direction K1 carrying of receiving is that the source network element of the identification information of D, the carrying of K2 byte is that the identification information of C exchanges, and forms new K1, K2, and to B-the transmission of C direction.Like this, B-〉the new K1 that sends of C direction, the protection switching request information purpose network element of K2 byte carrying be C, the source network element is D.As a result, A-〉the error code situation of B direction no longer influences network element C from D-〉A-〉B-〉the C path receives correct K1, K2 byte, network element C and D will set up bridge joint and switch and keep always, because C-〉D direction optical fiber catastrophe failure and interrupted service is restored.

As seen from the above description, adopt the reliable reverse method of optical transmission ring network of the present invention after, transmission looped network can be implemented reliable protection and switch under long-term error code situation, the efficient recovery interrupting service is arranged, avoid business repeatedly to damage.

Claims (2)

1. the method that optical annual network is reliably switched comprises by transmission direction and judges the direction that error code occurs, and forms by MSOH K1, the K2 byte that receives to be fit to the K1 that sends, the method for K2 byte; It is characterized in that having following steps:

S4, current network will produce K1, the K2 byte that the relative direction of long-term error code direction receives and transmit to described error code direction;

Behind the source network element ID information exchange of purpose network element ID that the K1 byte that S5, described current network are received described relative direction is carried, send improved MSOH K1, K2 byte to described relative direction with the carrying of K2 byte.

2. the method that optical annual network according to claim 1 is reliably switched is characterized in that:

Specifically comprise in the described step of judging the direction that error code occurs by transmission direction:

S1, current network detect an adjacent direction and long-term error code occurs;

S2, current network detect K1, the K2 byte that described error code direction and relative direction thereof are received;

S3, current network are received K1, the K2 byte of certain the network element section of striding catastrophe failure in described error code direction and relative direction thereof, and are entered pass-through state.

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