CN104954160A - Method for achieving multiple protection of bearer network, and bearer network - Google Patents

Abstract

The invention discloses a method for achieving the multiple protection of a bearer network, and the method comprises the steps: enabling SDH and PTN to be supported by an OTN (optical transmission network) in a unified manner; building different routing optical cables in all core interoffices of an OTN core layer; calculating the shortest path from a source end to a target end, and enabling the shortest path to serve as a protection path. The invention also discloses the bearer network achieving the multiple protection, and the bearer network comprises the SDH, the PTN, and the OTN. The SDH and the PTN are supporting by the OTN in a unified manner through a wave channel. The OTN comprises the core layer and a convergence layer, wherein the core interoffices of the core layer are provided with different routing optical cables. The OTN also comprises calculating equipment which is used for calculating the shortest path from the source end to the target end, and the shortest path serves as the protection path.

Description

A method for realizing multiple protection of bearer network and bearer network

technical field

The invention relates to the protection technology in the transmission network, in particular to a method for realizing multiple protection of the bearer network and the bearer network.

Background technique

At present, the bearer network includes: Synchronous Digital Hierarchy (SDH), Packet Transport Network (PTN), and Optical Transport Network (OTN), etc. Among them, 2G services are mainly carried on SDH , 3G services are mainly carried on the PTN.

The network structures of SDH, PTN, and OTN all include core layer, aggregation ring, and access ring. Specifically, the core layer of SDH is mainly carried by bare optical fibers, the aggregation ring of SDH is generally carried by optical cables, and long-distance sections are carried by OTN The SDH access ring is carried by optical cables; the core layer of PTN is carried by OTN or bare optical fibers, the aggregation ring of PTN is generally carried by OTN or optical cables, and the access ring of PTN is carried by optical cables; Independence and lack of unity, when optimizing and protecting SDH, PTN, and OTN respectively, it is not conducive to the full utilization of scarce protection resources; moreover, optimizing and maintaining SDH, PTN, and OTN will consume more manpower and material resources .

On the one hand, the existing SDH, PTN, and OTN core inter-office loops are only based on the electrical layer sub-wavelength 1+1 protection of SDH, PTN, and OTN’s own passive optical network (Passive Optical Network, PON) services; , the electrical layer sub-wavelength system mainly includes: a branch convergence unit, an electrical crossover unit, and a group convergence unit; the electrical crossover unit crosses the OTN basic frame unit, and when receiving an optical signal, the group convergence unit converges the OTN basic frame after the crossover Single unit, and then the branch convergence unit completes the demultiplexing function of one or more service signals on the branch side to realize flexible scheduling of sub-wavelengths at the electrical layer.

Taking an existing dense wavelength division multiplexing equipment in the metropolitan area as an example, briefly explain the principle of 1+1 sub-wavelength protection in the electrical layer. As shown in Figure 1, COMB is the branch line aggregation board, LD2 is the group line aggregation Clock and signal cross processing unit, a sub-wavelength signal of COMB is connected to CSUB through the backplane bus, and CSUB sends this signal to two different LD2s at the same time, and then the wavelength division optical channel (OPTICALCHANNEL, OCH) side of LD2 works separately Path and protection path, and then realize the "concurrent" function; at the receiving end, CSUB receives the service sent by LD2 from the working path and the protection path at the same time, and according to the optimal condition, selects the service with good signal quality to send to COMB, realizing "optimized Generally, it will choose to send the service of the working path to the COMB. When the service signal of the working path is interrupted or the quality deteriorates, CSUB will receive the service of the protection path to ensure the normal transmission of the service.

However, since the core inter-office loops of SDH, PTN, and OTN are only based on the electrical layer sub-wavelength 1+1 protection of SDH, PTN, and OTN’s own PON services, SDH, PTN, and OTN all require strict dual routing Separation; therefore, with the increase of business, the number of aggregation rings increases exponentially, and it is very difficult to overlap and separate the aggregation layer optical cables and core layer optical cables; when the separation is improper, multi-point faults in the core aggregation layer will also occur , causing a large number of business interruptions.

On the other hand, SDH, PTN, and OTN aggregation layer network protection generally adopts a single ring network protection, and for some sections, the optical line automatic switching protection (Optical Line Protection, OLP) system is used for overlay protection; the OLP system includes optical line automatic switching The protector and network management software, multiple optical line automatic switching protectors and a computer running network management software constitute the OLP system; on the optical transmission line, when the optical fiber is accidentally broken or the loss increases and the communication quality decreases, the OLP system can be used in a very short time. Automatically switch the optical transmission line from the main route to the backup route within a certain period of time. In this way, the failure of the optical cable can be effectively prevented, and the communication interruption time caused by the failure of the optical cable can be reduced from several hours to several milliseconds, thereby ensuring the normal operation of the communication system.

The working principle of the OLP system, as shown in Figure 2, there are two lines between site A and site B, the optical transmission system selects one of the lines as the main line, and the other line as the backup line, and the backup line is used for transmission The secondary signal or no signal is transmitted; when the main line or a certain optical fiber/optical cable in the main line fails and the communication quality drops, and the receiving end of the main line detects that the power of the signal has dropped, it will automatically route the transmission signal from the main line. Use the line to switch to the backup line, and the OLP equipment at the other end will switch the line to the backup line synchronously to ensure the normal transmission of signals.

However, for some sections of the network using OLP for overlay protection, because the OLP sections are scattered and lack regularity, it is impossible to realize the protection from the source end to the destination end of the three routes for key business areas, such as: county-level central stations.

Contents of the invention

In view of this, the embodiment of the present invention expects to provide a method and a bearer network for realizing multiple protection of the bearer network, to realize the unified bearer of SDH, PTN, OTN, the protection between the aggregation layer and the core layer, and the ring network caused by a double-break fault. When the protection fails, the protection of key areas of the convergence layer.

The technical scheme of the embodiment of the present invention is realized like this:

The embodiment of the present invention provides a method for realizing multiple protection of the bearer network, including: unifying the synchronous digital hierarchy system SDH and the packet transport network PTN on the optical transport network OTN; establishing different routes between each core office of the OTN core layer optical cable; calculate the shortest path from the source end to the destination end, and use the shortest path as a protection path.

Preferably, the unified carrying of SDH and PTN on the OTN includes: using a short-distance optical interface to connect with the OTN channel board, and carrying the SDH and PTN on the OTN through the channel.

Preferably, the calculating the shortest path from the source to the destination includes: calculating a cost value from the source to the destination, and obtaining the shortest path from the source to the destination according to the calculated minimum cost value.

Preferably, the calculation of the cost value from the source end to the destination end is: calculating the cost value from the source end to the destination end according to COST=(∑cost)×Q;

Among them, COST is the total paragraph cost value, cost is the cost value of each paragraph, and Q is the weight value.

Preferably, the paragraphs are: the distance between two sites, the cost is set according to actual needs, and Q is the ratio of the number of paragraphs passed from the core office to the destination node to the number of paragraphs in the OTN loop.

The embodiment of the present invention also provides a bearer network that realizes multiple protections, including: SDH, PTN, and OTN; the SDH and PTN are uniformly carried on the OTN through channels;

The OTN includes: a core layer and an aggregation layer, and each core office of the core layer is provided with different routing optical cables;

The OTN further includes: a computing device, configured to calculate the shortest path from the source end to the destination end, and the shortest path is used as a protection path.

Preferably, the unified carrying of SDH and PTN on the OTN includes: using a short-distance optical interface to interface with the OTN channel board, and carrying the SDH and PTN on the OTN through a channel.

Preferably, the calculating the shortest path from the source end to the destination end includes:

Calculate the cost value from the source end to the destination end, and obtain the shortest path from the source end to the destination end according to the calculated minimum cost value.

Preferably, the calculation of the cost value from the source end to the destination end is: calculating the cost value from the source end to the destination end according to COST=(∑cost)×Q;

Among them, COST is the total paragraph cost value, cost is the cost value of each paragraph, and Q is the weight value.

Preferably, the paragraphs are: the distance between two sites, the cost is set according to actual needs, and Q is the ratio of the number of paragraphs passed from the core office to the destination node to the number of paragraphs in the OTN loop.

The method and the bearer network for realizing multiple protection of the bearer network provided by the embodiment of the present invention first unify SDH and PTN on the OTN, so that when SDH, PTN, and OTN need to be optimized and maintained, the protection resources can be fully utilized ; Then establish different routing optical cables between each core office of the OTN core layer to realize automatic line protection switching and avoid separation difficulties caused by overlapping of multiple same routes and multi-point faults at the core layer and aggregation layer caused by improper separation; Finally, the shortest path from the source end to the destination end is calculated at the aggregation layer, and the shortest path is used as the protection path, so that when the ring network double-break fault causes the ring network protection to fail, the key service area is protected, and the network bearer is realized. Multiple protections maximize investment efficiency and protection efficiency.

Description of drawings

Figure 1 is a schematic diagram of the 1+1 protection principle of the sub-wavelength of the electric layer;

Figure 2 is a schematic diagram of the working principle of the OLP system;

FIG. 3 is a schematic diagram of a basic processing flow of a method for implementing network bearer multiple protection according to an embodiment of the present invention;

Fig. 4 is the schematic diagram of the optical network structure that SDH and PTN are unified carried on OTN in the embodiment of the present invention;

Fig. 5 is the network topology schematic diagram of establishing different routing optical cables between each core office of the OTN core layer according to an embodiment of the present invention;

Fig. 6 is the schematic diagram of the principle of establishing different routing optical cables between each core office of the OTN core layer to realize multi-point fault protection according to an embodiment of the present invention;

Fig. 7 is a schematic diagram of the shortest path calculation principle of the embodiment of the present invention;

FIG. 8 is a schematic diagram of the composition and structure of a bearer network implementing multiple protections according to an embodiment of the present invention.

Detailed ways

In the embodiment of the present invention, the SDH and PTN are uniformly carried on the OTN, different routing optical cables are established between each core office of the OTN core layer, and finally the shortest path from the source end to the destination end is calculated, and the shortest path is used as a protection path.

Specifically, the calculating the shortest path from the source end to the destination end includes: calculating a cost value from the source end to the destination end, and obtaining the shortest path from the source end to the destination end according to the calculated minimum cost value;

Wherein, the calculation of the cost value from the source end to the destination end includes: calculating the cost value from the source end to the destination end according to COST=(∑cost)×Q;

Here, COST is the total paragraph cost value, cost is the cost value of each paragraph, and Q is the weight value; the paragraph is: the distance between two sites, the cost is set according to actual needs, and Q is the core station to the destination The ratio of the number of sections the node passes to the number of sections in the OTN ring.

The basic processing flow of a method for multiple protection in the embodiment of the present invention is shown in Figure 3, including the following steps:

Step 101, uniformly bear SDH and PTN on OTN;

Specifically, the optical network structure that uniformly carries SDH and PTN on the OTN, as shown in Figure 4, uses a short-distance optical interface to connect with the OTN channel board, and connects SDH and PTN through 2.5G, or 10G, or 10GE channels carried on OTN;

Among them, when SDH and PTN are unified carried on OTN, it is necessary to separate the core layer of OTN from the aggregation layer, and separate the power supply system of the core layer of OTN from the aggregation layer, so as to avoid the failure of the OTN core equipment to cause the bearer service to be completely blocked;

When SDH and PTN are carried on the OTN, it is necessary to place an OTN device in each optical direction of the end office at the aggregation layer to ensure that the failure of the equipment in one direction does not affect the optical paths in other directions;

When carrying SDH and PTN on the OTN, it is also necessary to keep the topological connections and network elements between two or more core offices connected to the aggregation layer and each aggregation node consistent.

Step 102, establishing different routing optical cables between each core office of the OTN core layer;

Establish a network topology diagram of optical cables with different routes between each core office of the OTN core layer, as shown in Figure 5, because the optical cable at the aggregation layer is routed or overlapped with a core layer optical cable, it must not be routed with another core layer optical cable or overlap. Therefore, OLP switching can be realized through different routing optical cables between each core office of the core layer; when there is a fault with the same route or an overlapping point, it will automatically switch to another core layer optical cable route; thus ensuring that the core layer and the aggregation layer are not A double-break fault will occur.

Specifically, different routing optical cables are established between each core office of the OTN core layer. When the optical cable is constructed, the core layer is only responsible for the different routes of the optical cables in the core layer, and the aggregation layer is only responsible for the different routes of the optical cables in the aggregation layer. In this way, it can It simplifies the difficulty of route separation and avoids the potential overlap of multiple same routes; moreover, when the core layer and aggregation layer fail at the same time, it can protect the business from being affected.

The following explains in detail the principle of establishing different routing optical cables between each core office of the OTN core layer to achieve multi-point fault protection. As shown in Figure 6, the optical cable from core office A1 to core office B1 and the optical cable from core office A1 to core office D1 There is an overlap in a well in the urban area. When a landslide occurs in the territory, the optical cable from core office A1 to core office B1 and the optical cable from core office A1 to core office D1 will be interrupted at the same time. In Figure 6, the thick black solid line represents the routing of the optical cable, the thick black dashed line represents the routing of the OLP optical cable, and the star-shaped polygon represents the fault point.

In this embodiment, SDH and PTN are uniformly carried on the OTN, and different routes realized by OLP optical cables are set up between core office A1 and core office B1; The optical cable to core office B1 has the same route, and the optical cable from core office A1 to core office D1 has a different route from the OLP optical cable from core office A1 to core office B1; when the optical cable from core office A1 to core office B1 fails, the service from the core office The OTN link from A1 to core office B1 is switched to the OLP optical cable from core office A1 to core office B1. Similarly, the SDH and PTN links carried on the OTN maintain normal working status.

At this time, the service path from core office D to core office A1 is that after core office D goes to core office B1, it reaches core office A1 through the OLP link. business protection.

Step 103, calculating the shortest path from the source end to the destination end, and using the shortest path as a protection path;

Specifically, first calculate the cost value from the source end to the destination end, and then obtain the shortest path from the source end to the destination end according to the calculated minimum cost value;

Here, the calculation of the cost value from the source end to the destination end is: calculate the cost value from the source end to the destination end according to COST=(∑cost)×Q;

Among them, COST is the total paragraph cost value, cost is the cost value of each paragraph, and Q is the weight value; the paragraph is: the distance between two sites, cost is set according to actual needs, and Q is the core office to destination The ratio of the number of sections the node passes to the number of sections in the OTN ring.

The detailed process of calculating the cost value from the source end to the destination end in the embodiment of the present invention will be described in detail below with reference to FIG. 7 ;

Taking Figure 7 as an example, OTM-C node 1 in the key service area and OTM-C node 2 in the key service area are target sites, and core office 1 and core office 2 connected to the convergence layer are source sites; according to COST=(∑cost) ×Q calculates the cost value from the source end to the destination end; where,

Key business areas refer to counties or towns with a population of more than 100,000; because key business areas need to have three-way emergency protection capabilities, and the business is mainly concentrated in the core office, when performing business protection, it is necessary to implement one-way source to The destination end reaches a certain core office, that is, three-way protection from the source end to the destination end.

COST is the total paragraph cost value, cost is the cost value of each paragraph, and Q is the weight value;

Specifically, the distance between two sites is called a section; a section includes a trunk section and an end-office section, a section with a relay station at one end is a trunk section, and a section where all network elements at both ends are terminal equipment is called an end-office section ; Among them, the section between two nodes in a key service area cannot be used as a section, and the section between two core offices cannot be used as a section.

The cost of each section is set according to actual needs. In this example, the section cost of less than 80 kilometers is set to 1, the section cost of more than 80 kilometers and less than 100 kilometers is set to 2, and the section cost of more than 100 kilometers and less than 120 kilometers is set to 3. The cost of the relay section is 2, and the cost of the terminal section is 5.

Q is the ratio of the number of sections passed by the core office to the destination node and the number of sections in the OTN ring; The number of sections is 5, and the number of sections passed from the core office 2 to the OTM-C node 1 in the key service area is 3.

Therefore, the COST from the core office 1 to the OTM-C node 2 in the key service area=16×5/8=10;

COST=14×3/8=5.25 from core office 2 to OTM-C node 1 in the key service area;

According to the calculated path cost value, the shortest path from the source end to the destination end is the section from the core office 2 to the OTM-C node 1 in the key service area; that is, select this path for OLP.

In order to realize the above-mentioned multiple protection method, an embodiment of the present invention also provides a bearer network for multiple protection. The structure of the bearer network is shown in FIG. 8 , including: SDH11, PTN12, and OTN13;

Wherein, the SDH11 and PTN12 are uniformly carried on the OTN13 through the channel;

The OTN includes: a core layer and an aggregation layer, and each core office of the core layer is provided with different routing optical cables;

The OTN further includes: a computing device 110, configured to calculate the shortest path from the source end to the destination end, and the shortest path is used as a protection path.

Wherein, the computing device can be realized by existing software.

Here, the unified carrying of SDH and PTN on the OTN includes: using a short-distance optical interface to connect with the OTN channel board, and carrying the SDH and PTN on the OTN through the channel.

The calculating the shortest path from the source to the destination includes: calculating the cost value from the source to the destination, and obtaining the shortest path from the source to the destination according to the calculated minimum cost value.

Here, the calculation of the cost value from the source end to the destination end is: calculate the cost value from the source end to the destination end according to COST=(∑cost)×Q;

Among them, COST is the total paragraph cost value, cost is the cost value of each paragraph, and Q is the weight value. The paragraphs are specifically: the distance between two sites, the cost is set according to actual needs, and Q is the ratio of the number of paragraphs passed from the core office to the destination node to the number of paragraphs in the OTN loop.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention.

Claims (10)

1. A method for implementing multiple protections of a bearer network, the method comprising:

uniformly bearing a Synchronous Digital Hierarchy (SDH) system and a Packet Transport Network (PTN) on an Optical Transport Network (OTN);

establishing different routing optical cables among each core office of the OTN core layer;

and calculating the shortest path from the source end to the destination end, and taking the shortest path as a protection path.

2. The method for implementing multiple protections of a bearer network according to claim 1, wherein the unified bearer of SDH and PTN on OTN comprises: and the SDH and the PTN are borne on the OTN through the channels by utilizing the butt joint of the short-distance optical interface and the OTN channel board.

3. The method of claim 1, wherein the calculating the shortest path from the source end to the destination end comprises:

and calculating the consumption value from the source end to the destination end, and obtaining the shortest path from the source end to the destination end according to the minimum consumption value obtained by calculation.

4. The method of claim 3, wherein the calculating the source-to-destination cost value is:

calculating the consumption value from the source end to the destination end according to COST = (∑ COST) multiplied by Q;

wherein, COST is the total paragraph consumption value, COST is the consumption value of each paragraph, and Q is the weight.

5. The method of claim 4, wherein the paragraphs are: the distance between the two sites, cost, is set according to actual needs, and Q is the ratio of the number of paragraphs passed by the core office to the destination node to the number of paragraphs in the OTN loop.

6. A bearer network for implementing multiple protections, the bearer network comprising: SDH, PTN, and OTN; the SDH and the PTN are uniformly loaded on the OTN through a wave channel;

the OTN comprises: the optical fiber cable routing system comprises a core layer and a convergence layer, wherein different routing optical cables are arranged between core offices of the core layer;

the OTN further comprises: and the computing equipment is used for computing the shortest path from the source end to the destination end, and the shortest path is used as a protection path.

7. The bearer network for implementing multiple protections according to claim 6, wherein said unified bearer of SDH and PTN over OTN comprises: and the SDH and the PTN are borne on the OTN through the channels by utilizing the butt joint of the short-distance optical interface and the OTN channel board.

8. The bearer network for implementing multiple protections according to claim 6, wherein said calculating the shortest path from the source end to the destination end comprises:

and calculating the consumption value from the source end to the destination end, and obtaining the shortest path from the source end to the destination end according to the minimum consumption value obtained by calculation.

9. The carrier network for implementing multiple protections as claimed in claim 8, wherein the calculation of the source-to-destination cost value is:

calculating the consumption value from the source end to the destination end according to COST = (∑ COST) multiplied by Q;

wherein, COST is the total paragraph consumption value, COST is the consumption value of each paragraph, and Q is the weight.

10. The bearer network implementing multiple protections according to claim 9, wherein the paragraphs are: the distance between the two sites, cost, is set according to actual needs, and Q is the ratio of the number of paragraphs passed by the core office to the destination node to the number of paragraphs in the OTN loop.