SDH Network Topologies

SDH Network Topologies : Before discussing the SDH network topologies, a question arises as to what is the network topology? First of all, know what is the network topology. Network Topology-Computers, servers, mainframes, network devices, or other devices that share data with each other, whether it is wireless or by cable are called networks. Shape, layout or structure, of network is called the network topology.

Network topology determines the data path, which can be used between any pair of nodes in the network. Although the number of possible network topologies in SDH network is seemingly limitless. In this article, I will discuss specifically about the SDH network topologies. In SDH network, network topologies usually are- Point-to-Point Network, Chain Network, Ring Network, Hybrid Networks. Now these topics will be discussed further.

SDH Network

Ring topology is very important in all major topologies in SDH networks so ring topology is the most common and known topology of SDH. Linear or Chain topology is used when there is no need for protection of the network and the demographics of the sites are linear. The ring topology is the most common and known topology of SDH, because ring topology allowing great network flexibility and security.

The DWDM network can be in linear configuration or ring configuration usually DCM and regenerative cannot be used due to the short link length in metro networks. Amplifiers are also not used in some cases. ILA provides 1R regeneration against 3R regeneration of SONET regenerators due to ASE (amplifier spontaneous emission) signal becomes increasingly noisy as it is amplified by many EDFAs. DWDM systems should be capable of transmitting signals without regeneration for 8 spans of 22dB. If Regeneration is required in all the signals, two back to back terminals may be used or else an OADM may be used.

SDH Ring Network

I have already mentioned above that the ring topology is the most common and known topology of SDH network because SDH ring network allows great network flexibility and protection.

 

SDH network ring systems are five types, based on switching method combination i.e unidirectional or bidirectional switch and path or line switch, unidirectional or bidirectional ring are two-way traffic on fiber number-2 or 4 fibers.

In any types of network theoretically any combination between switching and routing direction is possible. But in the ring system of SDH network, as per below image uni-uni and bi-bi combination is used.

SNCP-ring (Unidirectional)

➤It is called Two-fiber Unidirectional Path protection Switch Ring (2F-UPSR)

➤No switching protocol is required. This is a simple and fast switching scheme.

 MS Dedicated Protection Ring

➤2-fiber Unidirectional Line protection Switch Ring (2F-ULSR)

➤In MSOH K1 and K2  is required.

SNCP-ring (Bidirectional)

➤2-fiber Bidirectional Path protection Switch Ring (2F-BPSR) 

➤At a path level ring must be controlled and protocol by K3 or K4 in POH is required.

 

4F MS-SP ring 

➤4-fiber Bidirectional Line protection Switch Ring (4F-BLSR)

➤In MSOH required protocol by K1 and K2.

2F MS-SP ring 

➤2-fiber Bidirectional Line protection Switch Ring (2F-BLSR)

➤In MSOH required Protocol by K1 and K2.

The terrestrial application and the transoceanic application are two different algorithm in 4/2F MS-SP ring.

Each device in the ring network is connected to the other two devices. Because of this, the ring is ready. In SDH network system rings may be in unidirectional with all traffic flow clockwise or anticlockwise around the rings or bidirectional. Because a unidirectional ring topology provides only one route between any two nodes. Unidirectional ring network can be interrupted by single link failure.

SDH Hybrid Network

It is a confluence of various topologies. Just like large organizations have a network of small networks. These networks are made up of different topology types. Hybrid networks are made by this group of small networks. Developing network topology will lead to more effective data communication systems in future.

Mesh Network is a new type of network topology. This type does not use a specific structure. Such as Tree or Star. However, in this case Mesh Node requires more than one connection to connect to other Nodes. The connection created by this structure creates a Mesh Network.

The advantage of mesh network is that they have their own medical system. If the Connection between 2 Nodes is interrupted. So the data is automatically sent to another node. Mesh Network is often used by wireless technology.

Additional two types of network topology are also discussed in SDH Network Topologies. I will discuss on these two types in very few words- SDH Star Network Topology and SDH Tree Network Topology.

SDH Star Network Topology

In this SDH network topology each device is connected to a Central Network switch. Message is sent via Node. It gets to the person concerned through the switch. The Star network is currently the most popular type of network topology. This type is used from small networks in the home to extended networks in large organizations.

SDH Tree Network Topology

Each device is connected to the Central Node individually or with the help of some device. The central Node is connected to another node. Therefore, a tree-like structure is formed in this structure.

This network is also called Hierarchical Network. It is used to exchange large amounts of data between organizations. If the SDH network topologies are shown together, such type of network will appear-

Last Word

Dear friends, seen in this article what is SDH Network topology and how SDH network topology works. I  hope you understand this article. If you like the post, then comment and share it. If you want any kind of information related to telecom, then tell me by commenting, I will always cooperate with you.