KR20030003943A - Dual node interconnection method for a synchronous optical transmission system - Google Patents

Abstract

PURPOSE: A dual node connection method for a synchronous optical transmission system is provided to transmit an inter-network traffic through a ring type network in case that inter-different two ring type networks are configured in an SDH(Synchronous Digital Hierarchy) network. CONSTITUTION: A network 1 sets a node B as a primary node, and sets a node C as a secondary node(S410). A network 2 sets a node F as a primary node, and sets a node G as a secondary node(S420). If a DNI(Dual Node Interconnection) channel setup is completed, a traffic transmission procedure is performed by a type set according to situation of the integrity of each network or a traffic transmission fault(S430).

Description

Dual node interconnection method for a synchronous optical transmission system

The present invention relates to a dual node access method of a synchronous optical transmission system. More specifically, when two different annular networks are configured in a synchronous digital hierarchy (SDH) network, traffic between networks is transmitted through the annular network. It relates to a dual node connection method of a synchronous optical transmission system suitably.

In general, a transmission facility consists of transmission media such as space, paired cable, coaxial cable, optical cable, and electronic devices installed along these media. The electronic device amplifies and reproduces a transmitted signal. In the transmission system, various types of station devices are installed between the exchange and the transmission line.

1 is a schematic structural diagram of a general transmission system.

According to Fig. 1, the transmission system includes a transmission terminal apparatus, a relay apparatus, multiplexing / demultiplexing, and a distribution apparatus. In such a transmission facility, a transmission terminal apparatus and a relay apparatus constitute a transmission system, and become nodes on a network for information transmission.

In the case of a network between synchronous optical transport systems, each node is configured in a ring using MSSPRING (Multiplex Section Shared Protection RING), so that each ring network can use the Dual Node Interconnection (DNI) feature. If it is not possible, the linear network must be additionally configured to transmit traffic between the annular networks, that is, the addition of the linear network for traffic transmission between the plurality of annular networks is required.

2 is a node connection diagram of a conventional synchronous optical transmission network.

In Fig. 2, the annular network consisting of A, B, C, and D is called Network 1, and the annular network consisting of E, F, G, and H is called Network 2. At this time, each node such as A and H is composed of 2.5G SDH equipment. In addition, an additional linear network connecting node A and node E is called network 3.

It is assumed that each annular network uses the MSSPRING schema.

For example, if you decide to send traffic from node A of network 1 to node E of network 2, the traffic is sent through network 3 connecting node A and node E because the conventional annular network does not support the DNI function. Should be.

However, if the linear network is flawless, there is no problem. However, when both the transmission and reception optical cables are disconnected between the two devices forming the linear network, stable traffic transmission cannot be expected. Since linear networks do not have the same self-healing capability as annular networks, traffic transmission defects are more likely to occur due to transmission line defects.

If you want to send traffic from one annular network to another annular network with two annular networks configured like this, you cannot add traffic through the already configured annular network. It is possible.

Therefore, the prior art has a problem that additional cost burden for configuring an additional linear network is required.

If the amount of traffic to be transmitted from one annular network to another is small, the traffic capacity of the added linear network is wasted.

In addition, when the optical cable connected between the devices in the linear network is disconnected, there is no self-healing capability and thus no traffic can be transmitted to the desired location.

The present invention was created to solve the above-mentioned conventional problems, and an object of the present invention is to provide traffic between networks through such a ring network when two different ring networks are configured in a synchronous digital hierarchy (SDH) network. It is to provide a dual node connection method of a synchronous optical transmission system to transmit the.

1 is a block diagram of a general transmission system.

2 is a node connection diagram of a conventional synchronous optical transmission network.

3 is a network configuration to which a dual node access method of a synchronous optical transmission system according to an embodiment of the present invention is applied.

4 is a flowchart of a dual node access method of a synchronous optical transmission system according to an embodiment of the present invention.

FIG. 5 is a flow chart of each annular network defect in FIG.

FIG. 6 is a flowchart illustrating a failure in the triborder receiving side of the node F in FIG. 4; FIG.

Fig. 7 is a flowchart of failure in the EAST receiving side of NodeB.

A dual node access method of the synchronous optical transmission system of the present invention for achieving the above object comprises the steps of setting a primary node and a secondary node by selecting two nodes for each annular network on the transmission network; Setting the traffic transport channel between each network as a dual node interconnection channel, wherein the primary node uses a branch / pass scheme and the secondary node uses a schema to branch traffic channels through the primary node, one For the traffic sent through the primary node and the secondary node in the annular network of, the primary ring of the other annular network connected to the network is received through the low speed line and the traffic received through the high speed line through the secondary node. Characterized by including the step of selecting good quality traffic.

The present invention according to this configuration does not form a new linear network when transmitting traffic between annular networks.

In the present invention, a specific channel is selected from a node having traffic to be transmitted to another annular network among the nodes constituting each annular network, and the transmission traffic between annular networks is allocated to the channel. Traffic transmitted through the specific channel selected by the node to which the traffic is transmitted is transmitted to another annular network.

By selecting two specific devices among the nodes constituting the annular network, the node can transmit and receive traffic with other annular networks, so that traffic can be transmitted between annular networks without adopting a linear network.

Thus, in establishing a connection between two different annular networks, two nodes of each annular network are interconnected. By transmitting the same transmission traffic through two devices in one annular network, the traffic can be transmitted through the redundant optical cable even when one optical cable is disconnected in the connection configuration between the annular networks.

As such, a plurality of connection settings between annular networks are secured to stabilize traffic transmission and improve network survivability. And it is possible to improve the traffic self-recovery capacity of the traffic transmission channel between the annular network of the synchronous transmission system.

Therefore, when configuring a traffic transmission channel between annular networks of a synchronous transmission system, it is possible to reduce the cost burden and waste of traffic resources due to the conventional additional linear network configuration.

And the connection between the annular network is set by selecting two nodes in the network. One of the two nodes is called a primary node and the other is called a secondary node. The specific channel through which traffic is transmitted between annular networks is called a dual node interconnect channel (or DNI channel).

In order to complete the traffic transmission through the DNI channel, the primary node uses the drop / continue scheme when setting the DNI channel, and the secondary node branches the DNI channel connected from the primary node as it is. Use

In addition, the primary node configured for the DNI channel is operated by including a service selection function.

The service selection function is a path switching scheme applied when the DNI function needs to be performed while using MSSPRING among schemas that form a ring network and perform protection switching.

Service selection is based on general Path Switch Criteria. The general route switch transmits the same traffic through the high-speed line in both the WEST and EAST directions from one device, and selects the higher-quality traffic among the two identical traffic received through the high-speed line from the receiving device. to be.

In contrast, the service selection of the present invention is based on the traffic transmitted through the primary node and the secondary node in one annular network through the secondary node and the traffic received through the slow line from the primary node of another network connected to the network. It is a system that selects the higher quality traffic among the traffic received through the high speed line.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

3 is a diagram illustrating a network configuration to which a dual node access method of a synchronous optical transmission system according to an exemplary embodiment of the present invention is applied, and FIG. 4 is a flowchart of a dual node access method of a synchronous optical transmission system according to an exemplary embodiment of the present invention. Fig. 4 is a flow chart of each annular network defect, Fig. 6 is a flow chart of the node F tributary receiving side failure in Fig. 4, and Fig. 7 is a flow chart of the node B's EAST receiving side failure.

According to Fig. 3, a plurality of annular networks are formed on the transport network.

In this embodiment, different networks are each configured in a ring using the MSSPRING scheme, and each ring network uses the DNI function to perform traffic transmission between the stable and reliable annular networks. The traffic transmission procedure between each node in the annular network is as known.

For example, each node on the annular network can be implemented with 2.5G SDH equipment. Here, the annular network composed of four nodes A 310, B 311, C 312, and D 313 is called 'network 1', and four nodes E 314, F 315, and G are referred to as 'network 1'. An annular network composed of 316 and H 317 will be referred to as 'network 2'.

The MSSPRING schema is applied between Network 1 and Network 2.

According to Fig. 4, the transmission procedure in the case of transmitting traffic from network 1 to network 2 is as follows.

Set two nodes for Network 1 and 2 as Primary Node and Secondary Node, respectively. That is, in network 1, node B 311 is set as a primary node, and node C 312 is set as a secondary node. In network 2, node F 315 is set as a primary node, and node G 316 is set as a secondary node. In this way, the DNI channel is set (S410 to S420).

When the DNI channel is configured, the traffic transmission procedure is performed in a manner set according to the defects of each network or the traffic transmission failure. The criterion of this determination will be abbreviated as 'channel situation' (S430).

Channel conditions that may be scheduled in step S430 are 'an annular network flawlessness', 'a tributary receiving side failure of node F', or an 'EAST receiving side failure of node B'. The illustrated channel situation does not exclude the schedule of another channel situation. Therefore, the present invention can be applied by setting various channel conditions according to the operating environment and implementing control logic accordingly.

The lower routine performed by branching according to the channel condition of step S430 will be described. In this case, 'TS' indicates an timeslot and 'TS1' is indicated to mean timeslot 1 in the accompanying drawings. Hereinafter, timeslot 1 is a working time slot, and timeslot 25 is a protection time slot.

According to FIG. 5, when the channel condition is 'each annular network flawless' state, the traffic coupled at the node A 310 is set to be allocated to the output side timeslot 1 (or TS1) in the WEST direction. This combined traffic is allocated and transmitted to timeslot 1 (TS1) of the optical cable connecting node A 310 and node B 311 (S510).

Since the Node B 311 is a primary node, the branch / pass scheme is used to branch traffic received through the receiving side timeslot 1 in the EAST direction while passing the traffic to the node C 312 which is the secondary node ( S520).

The node C 312 branches the traffic received through the receiving side timeslot 1 in the EAST direction (S530).

Traffic transmitted through the tributaries of Node B 311 and Node C 312 is transmitted from Network 1 to Network 2 via an interconnection between the networks (S540).

In the network 2, since the node G 316 is a secondary node, the node G 316 is configured to allocate traffic received through the receiver side timeslot in the tributary direction to the output side timeslot 1 in the WEST direction. Thus, the traffic received through the node G 316 is allocated and transmitted to timeslot 1 of the optical cable connecting the node G 316 and the node F 315 (S550).

The node F 315, which is the primary node, then selects either traffic received through the receive side timeslot in the tributary direction or traffic received through the node G 316. At this time, the traffic received from the tributary is selected and set to be assigned to the output time slot 1 in the WEST direction. The traffic selected at the node F 315 is allocated and transmitted to timeslot 1 of the optical cable connecting the node F 315 and the node E 314 (S560).

The node E 314 branches the traffic received through the receiving side timeslot 1 in the EAST direction (S570).

When the channel condition is 'each annular network flawlessness', this traffic transmission procedure is performed. When the traffic is transmitted, the process returns to the determination of the channel condition.

In addition, according to FIG. 6, there is a case where the channel status is determined as "triborder receiving side failure of node F" in step S430. In the network 2, the lower routine according to the failure of the tributary receiving side of the node F performs the traffic transmission procedure as follows.

First, a part of the initial procedure of the traffic transmission procedure of each annular network flawless state is performed.

That is, the traffic that is coupled at node A 310 is set to be allocated to output side time slot 1 (or TS1) in the WEST direction, and the time slot of the optical cable connecting the traffic between node A 310 and node B 311. 1 is allocated to TS1 and transmitted (S610).

The node B 311 branches the traffic received through the receiving side timeslot 1 in the EAST direction using the branch / pass scheme, and passes the traffic to the node C 312 which is the secondary node (S620).

The node C 312 branches the traffic received through the receiving side timeslot 1 in the EAST direction (S530).

Traffic transmitted through the tributaries of Node B 311 and Node C 312 is transmitted from Network 1 to Network 2 via an interconnection between networks (S640).

In the network 2, since the node G 316 is a secondary node, the node G 316 is configured to allocate traffic received through the receiver side timeslot in the tributary direction to the output side timeslot 1 in the WEST direction. Thus, the traffic received through the node G 316 is allocated and transmitted to timeslot 1 of the optical cable connecting the node G 316 and the node F 315 (S650).

Node F 315, which is the primary node, then selects one of the traffic received through the receive side timeslot in the tributary direction and the traffic received through node G 316. At this time, the selected traffic becomes traffic received through the equipment G 316, and this traffic is set to be allocated to the output side timeslot 1 in the WEST direction. The traffic selected at node F 315 is assigned and transmitted to timeslot 1 of the optical cable connecting node F 315 and node E 314. At this time, the transmission procedure is different from the transmission procedure in the state of the channel 'no annular network flawless' state (S660).

Subsequently, the same procedure as that of the transmission procedure of 'each annular network defect free' state is performed.

That is, the node E 314 branches the traffic received through the receiving side timeslot 1 in the EAST direction (S670).

If the channel condition is "tribate receiver side failure of node F", this traffic transmission procedure is performed.

As shown in FIG. 7, when the channel condition is 'EAST receiving side failure of node B' in step S430, the combined traffic is allocated to output side timeslot 1 in the WEST direction (S710).

In this case, the same traffic is allocated to the output side timeslot 25 in the EAST direction by instant ring switching of the MSSPRING network due to the failure of the EAST receiving side of the Node B 311 (S720).

Traffic allocated in step S720 is allocated and transmitted to timeslot 25 of the optical cable connecting the nodes A-D-C-B (S730).

Node B 311 then branches the same traffic received via receive side timeslot 25 in the WEST direction, instead of traffic received through receive side timeslot 1 in the EAST direction by ring switching, while splitting that traffic into the secondary node. The node C 312 is passed through (S740).

Subsequent transmission procedures are performed in the same manner as the procedures of S530 to S570 in the transmission procedures in the state of 'each annular network defect. In the accompanying drawings, this transmission procedure is indicated by the reference numerals S750 to S760.

When the different networks are configured in a ring like this, when the traffic is transmitted from one annular network to another annular network, the traffic is transmitted through the annular network that is already configured. It becomes unnecessary.

In addition, since traffic is transmitted through an annular network having excellent self-healing capability, even if any part of the optical cable of the annular network is disconnected, traffic can be safely transmitted within its annular network through a protection switching scheme.

In addition, any part of the interconnection between the primary node and the secondary node between different annular networks fails to connect by transmitting the same traffic through the primary and secondary nodes through the branch / pass scheme in their annular network. This will allow traffic to be safely sent to other annular networks.

The embodiments described above are within the scope of changes, modifications, and equivalents of the present invention. Therefore, the claims of the present invention are not limited to the description of the present embodiment.

According to the dual node access method of the synchronous optical transmission system of the present invention, it is possible to efficiently operate the network and increase the resource utilization by eliminating the cost and traffic resource wastage that is required to form a conventional linear network.

When the present invention is applied, the network self-recovery capability of the optical transmission system is excellent, and even when the optical cable of the annular network is partially cut, each network has an effect of stably transmitting traffic in its own annular network.

In addition, even when some of the interconnection of the different annular networks fail to access when the present invention is applied, it is possible to safely transmit traffic to another annular network, thereby improving network survivability.

Claims (6)

(A) selecting two nodes for each annular network on the transport network and setting a primary node and a secondary node, respectively; Setting the traffic transport channel between each network as a dual node interconnection channel, wherein the primary node uses a branch / pass scheme and the secondary node uses a schema to branch traffic channels through the primary node, one For the traffic sent through the primary node and the secondary node in the annular network of, the primary ring of the other annular network connected to the network is received through the low speed line and the traffic received through the high speed line through the secondary node. And (b) selecting the traffic having good quality. The method of claim 1, wherein the primary node, According to the service selection function, the traffic sent through the primary node and the secondary node in one annular network is high-speed through the secondary node and the traffic received through the slow line from the primary node of the other network connected to the network. A method for accessing a dual node of a synchronous optical transmission system, characterized in that a higher quality traffic is selected among the traffic received through a line. The method according to claim 1 or 2, Each annular network transmits the same traffic through the primary node and the secondary node according to the branch / pass scheme, and dual nodes are interconnected between the primary node and the secondary node between different annular networks. Node connection method. The method of claim 2, wherein the step (b) is performed in the case of defects of the annular networks connected to each other, If the traffic combined in each network is assigned to a working timeslot and transmitted to a primary node of the network, the primary node branches / passes the received traffic; Branching the traffic passing through the primary node by a secondary node; Transmitting tributary transmission traffic between the primary node and the secondary node on one side network to the primary node and the secondary node of the other side network; Transmitting, by a secondary node, a receiving node to a primary node of a corresponding network on a network receiving the tributary transmission traffic; On the network receiving the tributary transmission traffic, the primary node allocates and transmits the tributary side receiving traffic among the traffic received at the secondary node of the network and the traffic received at the tributary to a working time slot, And branching the transmitted traffic at a specific node. The method of claim 2, wherein step (b) comprises: When the annular networks connected to each other are called network 1 and network 2, when a tribological receiver side failure of the primary node of network 2 occurs, When traffic from network 1 is assigned to the working timeslot and sent to the primary node of network 1, the primary node of network 1 branches / passes the incoming traffic, and the secondary node of network 1 Branching the traffic that has passed; Tributary transmission traffic between the primary node and the secondary node of the network 1 is transmitted to the primary node and the secondary node of the network 2, the second node in the network 2 receiving the tributary transmission traffic is received by the tributary Transmitting the traffic to a primary node of network 2; The primary node of network 2 allocates and receives the traffic received through the secondary node of network 2 to timeslot 1 among the traffic received from the secondary node of network 2 and the traffic received from the tributary, and transmits from the designated node. And a step of branching the traffic which has been carried out. The method of claim 2, wherein step (b) comprises: When the annular networks connected to each other are called network 1 and network 2, when a specific receiver of the primary node fails in network 1, When traffic combined in network 1 is allocated to a working time slot and transmitted to a primary node of network 1 through a failed receiving side, the transmission traffic is allocated to a protection time slot and transmitted by ring switching according to a receiving side failure. Receiving at the primary node of 1; Receiving, by the primary node of network 1, branched / passing ring-switched traffic through an uninterrupted receiving side timeslot, and branching traffic that has passed through the primary node of network 1 by a secondary node of network 1; Tributary transmission traffic between the primary node and the secondary node of the network 1 is transmitted to the primary node and the secondary node of the network 2, the second node in the network 2 receiving the tributary transmission traffic is received by the tributary Transmitting the traffic to a primary node of network 2; The primary node of network 2 allocates and receives the traffic received through the secondary node of network 2 to timeslot 1 among the traffic received from the secondary node of network 2 and the traffic received from the tributary, and transmits from the designated node. And a step of branching the traffic which has been carried out.