Ethernet Over SONET, Packet Over SONET, WDM – Alternative to SDH and PDH

SDH (Synchronous Digital Hierarchy) and PDH (Parallel Data Highway) are digital transmission technologies that work together in the network. They improve network reliability and performance through efficient data transmission and flexible resource allocation. There are many alternatives to SDH and PDH. The most common of which are WDM technology, Ethernet Over SONET (EOS) and Packet Over SONET (POS). What is Ethernet Over SONET? What is Packet Over SONET? By reading this article, you can learn the following:

What is Ethernet Over SONET;

What is Packet Over SONET;

What is WDM Technology;

Advantages of Ethernet Over SONET, Packet Over SONET and WDM;

Use of Ethernet Over SONET, Packet Over SONET and WDM equipment.

Part I. What is Ethernet Over SONET? What are the advantages of it? How to use Ethernet Over SONET device?

What is Ethernet Over SONET?

EOS called Ethernet Over SONET/SDH. It is a mapping method that encapsulates Ethernet frames and then maps them to the VC (virtual container) of SDH/SONET.

Ethernet Over SONET is also a technical solution that uses SDH networks to carry Ethernet services.

The implementation of EOS technology relies on MSTP (Multi-Service Transport Platform) equipment.

MSTP equipment has an Ethernet interface and can be directly connected to routers or switches to realize the access of Ethernet services to the SDH network.

The multi-service board in the MSTP equipment completes the mapping and encapsulation from Ethernet to VC. It has Layer 2 capabilities to ensure efficient transmission of Ethernet data on the SDH network.

Through Ethernet Over SONET technology, Ethernet data can be transmitted over long distances and large capacity on SDH networks to meet the growing needs of telecommunications services.

Ethernet Over SONET STM-4 Converter

Ethernet Over SONET STM-4 Converter

More types of Ethernet Over SONET product about Baudcom Click here…

What are the advantages of Ethernet Over SONET (EOS)?

1.Can reduce POS optical port interconnection costs

EOS effectively reduces the optical port interconnection cost of POS through a series of technical features and optimization strategies. Here are some of the main ways:

(1)Reuse and Share Resources

Ethernet Over SONET technology makes full use of the SDH network infrastructure. It achieves efficient transmission of Ethernet services on the SDH network by multiplexing and sharing SDH optical port resources.

This avoids the need to configure separate optical ports for each Ethernet service. Thereby reducing the cost of optical port interconnection.

(2) Simplify the Network Structure

Ethernet Over SONET technology simplifies the network structure and reduces the number and complexity of network devices.

By directly mapping Ethernet services to SDH VCs, EOS reduces intermediate conversion links. It reduces network equipment investment and maintenance costs.

(3) Efficient Data Encapsulation and Mapping

Ethernet Over SONET uses efficient Ethernet frame encapsulation and mapping technology to encapsulate Ethernet data into a format suitable for transmission in SDH networks.

This encapsulation method reduces the cost of data conversion. It improves transmission efficiency, and further reduces the cost of optical port interconnection.

(4)Unified Network Management

EOS technology uses the unified network management function of MSTP equipment. Realizes end-to-end management of Ethernet services.

This management method simplifies the complexity of network operation and maintenance, reduces operation and maintenance costs. It also improves the reliability and stability of the network.

Ethernet Over SONET Ring Network application

Ethernet Over SONET Ring Network application

(5) Flexible Bandwidth Allocation

EOS supports flexible bandwidth allocation and can dynamically adjust bandwidth resources according to business needs. This avoids waste of bandwidth resources and improves bandwidth resource utilization.

Further reducing the cost of optical port interconnection.

2.Good Scalability and Flexibility

The scalability of Ethernet Over SONET is reflected in the following aspects:

(1) Network Capacity Extension

EOS is designed with the growing needs of network capacity in mind.

It allows operators to gradually increase network bandwidth and transmission capacity according to business needs to meet the growing Ethernet business needs.

This scalability enables EOS to adapt to network environments of all sizes. Including small local area networks and large wide area networks.

(2) Service Type Extension

EOS not only supports the transmission of Ethernet services, but can also support other types of services through technology upgrades and extensions.

Such as IP, MPLS, etc.

The scalability of this service type makes EOS a versatile network transmission platform. It can meet the needs of different businesses.

The flexibility of EOS is reflected in the following aspects:

(1)Business Configuration Flexibility

Ethernet Over SONET supports flexible service configuration and can dynamically adjust service parameters and transmission strategies according to user needs and network conditions.

This enables operators to provide customized network solutions based on different business scenarios to meet the different needs of users.

(2) Network Topology Flexibility

EOS supports a variety of network topologies, such as ring network, star network, mesh network, etc.

This flexibility enables operators to choose the most suitable topology based on the actual network environment. It improves network reliability and performance.

(3)Device Compatibility

EOS technology has good equipment compatibility. It can realizes interconnection and interoperability with SDH equipment of different manufacturers and different models.

This reduces the cost of equipment purchase. It also simplify equipment management and maintenance for operators.

How to use Ethernet Over SONET equipment correctly?

Proper use of EOS devices is divided into many steps.

Step 1: Make sure the device is installed correctly and connected to the network;

Including the physical connection of the device, power access, and related configuration settings.

Once the device is successfully connected and powered on, network configuration and service configuration can begin.

Step 2: Configure the network.

Users need to configure the Ethernet interface and SDH interface parameters of the Ethernet Over SONET device to ensure that the device can correctly access the network and communicate with other devices.

This includes setting network parameters. Such as IP address, subnet mask, gateway, and configuring related parameters such as SDH channels and time slots.

Step 3: Configure the business.

Users can configure EOS business type, bandwidth, Qos (Quality of Service) and other parameters according to actual needs.

Through flexible configuration, EOS devices can meet the needs of different business scenarios and provide efficient and reliable data transmission services.

Step 4: Performance Monitoring

After the configuration is completed, Ethernet Over SONET can start working normally.

It automatically maps Ethernet signals into frames and transmits them over the network.

During the transmission process, EOS devices can also provide network management and maintenance functions. It helps users monitor network status, solve problems, and optimize performance.

Part II. What is Packet Over SONET? What are the advantages of it? How to use Packet Over SONET equipment correctly?

What is Packet Over SONET?

POS called Packet Over SONET/SDH is an important telecommunications transmission technology.

It uses the high-speed transmission channel provided by SONET (Synchronous Optical Network) or SDH (Synchronous Digital Hierarchy) to directly transmit IP data services.

POS technology is widely used in city area networks and wide area networks to provide high-speed, reliable, point to point IP data connections for the network.

In Packet Over SONET technology, IP data packets are first packaged using link layer protocols (such as FR, PPP, HDLC, etc.).

Then, the service adapter of the SONET/SDH channel layer maps these packaged IP data packets into the SONET/SDH synchronization payload, and then loads the payload into a SONET/SDH frame.

Finally, these frames are transmitted over the optical network.

POS technology retains the connectionless characteristics of IP and provides a data link layer as the interface between IP and SONET/SDH.

The emergence of POS technology makes it possible to eliminate ATM. It directly runs IP data packets on the SDH network, thereby simplifying the network structure and reducing costs.

In addition, POS technology also has good scalability and flexibility.

It can dynamically adjust the service scale according to business needs and increase the concurrency of the system.

At the same time, Packet Over SONET technology also supports a variety of network topologies. This making it easy for operators to select and configure according to the actual network environment.

What are the advantages of POS?


The efficiency of Packet Over SONET is mainly reflected in the following aspects:

First of all, POS technology uses the high-speed transmission channel of SONET/SDH to directly transmit IP data packets, realizing high-speed data transmission.

As mature transmission technology, SONET/SDH has stable transmission performance and efficient bandwidth utilization. This allowing POS to maintain excellent performance in a high-speed network environment.

Secondly, POS technology uses an efficient packaged. It mapping mechanism to package IP data packets into a format suitable for SONET/SDH transmission.

This encapsulation method ensures the integrity and accuracy of data during transmission. It reducing the overhead of data conversion and processing, and improving transmission efficiency.

In addition, Packet Over SONET technology also has efficient flow control and congestion management mechanisms.

It can adjust the data transmission rate in real time according to network conditions to avoid network blocking and data loss.

At the same time, POS technology also supports a variety of quality of service (QoS) protection mechanisms. This ensures priority transmission of key business data and improve the overall performance and stability of the network.

Finally, the efficiency of POS technology is also reflected in its flexibility and scalability.

The Packet Over SONET system can be flexibly configured and expanded according to business needs. This supports a variety of network topologies and interface types.

This enables POS to adapt to network environments of different sizes and complexities. It also provides efficient and reliable data transmission services.

Advantage of Packet Over SONET High Speed

Advantage of Packet Over SONET High Speed

2.Easy to Manage

Packet Over SONET has significant advantages in ease of management. This providing operators with a convenient and efficient network management experience.

The ease of management of POS is reflected in:

First of all, POS technology adopts standardized interfaces and protocols.

This enhances interoperability between different manufacturers and devices.

This means operators have greater flexibility in selecting and managing equipment from different vendors without worrying about compatibility issues.

This standardized design greatly simplifies the complexity of network management and reduces maintenance costs.

Secondly, POS technology has centralized network management capabilities.

Through a unified network management platform, operators can monitor the operating status of the POS network in real time. Including key indicators such as transmission rate, bandwidth utilization, and error rate.

This centralized management method allows operators to quickly identify and solve potential problems to ensure stable operation of the network.

In addition, POS technology also provides rich network management functions.

For example, it supports remote configuration and monitoring. It allowing operators to configure, software upgrade and troubleshoot POS devices through remote access.

This not only reduces the need for on-site maintenance, but also improves response speed and efficiency.

At the same time, POS technology also has automatic alert and fault location functions. Once a network fault occurs, the system can automatically trigger an alert and mark the fault location. This helping operators quickly locate and solve the problem.

Finally, the ease of management of Packet Over SONET technology is also reflected in its scalability and flexibility.

The POS system can be flexibly expanded and configured according to business needs. This supports multiple business types and transmission types.

This enables operators to gradually upgrade and expand POS networks based on network development needs to meet changing business needs.


POS occupies an important position in communication networks with its excellent reliability.

The reliability of POS is mainly due to its advanced design, high-quality equipment and strict quality assurance measures.

First, POS technology uses standardized protocols and interfaces.

This ensures compatibility and interoperability between different manufacturers and devices.

This standardized design reduces the risk of failure due to mismatch between equipment and systems. Thereby increasing overall system reliability.

Secondly, POS equipment usually uses high-quality hardware and software components and undergoes strict testing and quality control to ensure that it operates stably for a long time.

These devices have anti-interference, anti-vibration and other characteristics. It can adapt to various harsh working environments.

In addition, POS systems also have automatic fault detection and recovery mechanisms.

Such a mechanism enables it to promptly locate and repair problems when failures occur, ensuring network continuity and availability.

Furthermore, Packet Over SONET technology uses multi-level security measures to protect the security and correctness of data transmission.

This includes data encryption, authentication, access control and other mechanisms to effectively prevent data leakage and illegal access.

These security measures not only ensure the security of the POS system itself, but also improve the reliability of the entire communication network.

In addition, POS technology also has powerful network management functions.

This can monitor the status and performance of the network in real time and detect. It also deal with potential problems in a timely manner.

Operators can remotely configure, monitor and maintain POS equipment through the network management platform. It reducing the need for on-site maintenance and improving management efficiency and convenience.

How to use Packet Over SONET equipment correctly?

Using POS equipment involves device configuration, connection and data transmission.

Step 1: Device Configuration

First, the Packet Over SONET device needs to be initially set up according to the needs and configuration of the network.

This includes setting network parameters. Such as the device’s IP address, gateway, and subnet mask. As well as configuring related transmission protocols and parameters.

Make sure the POS device can properly connect to the network and communicate with other devices.

Step 2: Device Connection

Connect POS equipment to the SONET/SDH network through optical fiber or other transmission media.

Ensure that the connection is stable and reliable and meet the needs of data transmission.

Step 3: Data Transmission Configuration

Configure data transmission-related parameters on the Packet Over SONET device. Such as transmission rate, encapsulation protocol, etc.

These parameters need to be set according to specific business needs and network environment to ensure that data can be transmitted efficiently and accurately.

Step 4: Start Data Transfer

After the configuration is completed, start the data transmission function of the POS device.

The device will start receiving IP data packets from the SONET/SDH network, encapsulating and transmitting them.

Step 5: Monitor and Manage

During the data transmission process, POS equipment can be monitored and managed in real time through the network management platform.

This includes viewing the operating status of the device, key indicators. Such as transmission rate and error rate. And make necessary configuration adjustments and troubleshooting.

Part III. What is WDM technology? What are the advantages of it? How to use WDM equipment correctly?

What is WDM technology?

WDM’s full name is Wavelength Division Muliplexing. It is an optical fiber communication technology.

It increases bandwidth by allowing different data streams at different frequencies to be sent simultaneously through a single fiber optic network.

The working principle of WDM technology is to combine two or more optical carrier signals of different wavelengths (carrying various information) at the transmitting end. This through a multiplexer (Multiplexer), and separate the optical carriers of various wavelengths.

And coupled to the same optical fiber of the optical line for transmission. At the receiving end, the optical carriers of various wavelengths are separated by a demultiplexer. And then further processed by the optical receiver to restore the original signal.

In general, WDM technology is a technology that simultaneously transmits two or many optical signals of different wavelengths in the same optical fiber.

WDM Multiplexer

WDM Multiplexer

More types of WDM product about Baudcom Click here…

What are the advantages of WDM?

The salient features of WDM technology include efficiency, reliability and adaptability.


The efficiency of WDM is mainly reflected in the following aspects:

(1) Resource Optimization

Through WDM technology, multiple signals can be transmitted in parallel in the same optical fiber without the need to lay separate optical fibers for each signal.

This not only reduces the cost of laying fiber, but also reduces the complexity of maintaining and managing multiple fibers.

Therefore, WDM technology can significantly improve resource utilization.

(2) Increased Flexibility

WDM technology is compatible with a variety of communication protocols. This means it can easily combine different types of signals into the same transmission system.

This flexibility enables WDM to adapt to different communication needs.

Whether it is voice, data or video transmission, efficient transmission can be achieved through WDM technology.

(3)Bandwidth Extension

WDM technology allows multiple optical signals of different wavelengths to be transmitted simultaneously in the same optical fiber.

This means that compared to traditional single-wavelength transmission, WDM can significantly expand the bandwidth of optical fibers, thereby increasing transmission capacity.

This is very attractive for application scenarios that require high-speed and large-capacity data transmission.


Although the implementation of WDM technology may involve some additional equipment and complexity.

However, in scenarios that require large-scale data transmission. The use of WDM technology can greatly reduce the transmission cost per unit of data.

(5)Capability Extension

Theoretically, with the continuous improvement of technology, the capacity of WDM systems can be continuously expanded. By adding more wavelength channels or adopting more advanced modulation technology, the transmission capabilities of WDM systems can be further improved.

This enables WDM technology to continue to meet the growing demand for data transmission.


WDM technology uses a unique optical signal transmission method.

Low loss characteristics, error correction and tolerance mechanisms, and simplified system structure ensure the reliability of data transmission.

First, optical signals are immune to electromagnetic interference.

This means that during the transmission process, the optical signal is not easily affected by the external electromagnetic environment. Thus ensuring the stability and accuracy of the transmission.

Secondly, WDM technology uses the low-loss band of optical fiber to make the transmission loss of optical signals in the optical fiber extremely low, further enhancing the reliability of transmission.

In addition, because the WDM system can transmit multiple independent optical signals in a single optical fiber.

Even if there is a problem with a signal at a certain wavelength, signals at other wavelengths can be transmitted normally. This improves the fault tolerance of the system.

In addition, WDM systems are usually equipped with error correction and error tolerance capabilities. This can detect and correct errors during transmission.

This mechanism can effectively reduce data loss or distortion caused by transmission errors. It also improves the reliability of data transmission.

Finally, WDM systems have a relatively small number of active devices.

This reduces system complexity and failure rates.

At the same time, due to the fast transmission speed and high bandwidth of optical signals. The WDM system can complete the transmission of large amounts of data in a short time. This reducing potential problems caused by transmission delays.


WDM has good adaptability, which is mainly reflected in the following aspects:

First of all, WDM technology can interact and integrate with a variety of communication technologies.

Whether it is SDH, PDH or ATM protocols, WDM can perfectly connect with them for efficient data transmission.

This compatibility enables WDM technology to adapt to different communication environments and needs. Is achieves the integration and fusion of multiple communication technologies.

Secondly, WDM technology is also highly adaptable to different network topologies and architectures.

Regardless of different network structures such as point-to-point, ring or mesh, WDM technology can be flexibly configured and optimized according to specific needs to meet different transmission requirements.

In addition, WDM technology is highly scalable.

With the continuous development of communication technology and changing business needs.

WDM systems can easily expand capacity and improve performance by adding wavelength channels and upgrading equipment.

This scalability enables WDM technology to remain at the forefront of technology for a long time and meet the growing communication needs.

Finally, WDM technology is also highly standardized.

There are relevant international and domestic standards and specifications to guide WDM technology. This makes WDM equipment produced by different manufacturers compatible and interoperable with each other. It improving the adaptability and wide application of WDM technology.

WDM Technology Application

WDM Technology Application

How to use WDM equipment correctly?

There are multiple steps to using a WDM device.

Step 1: Equipment Preparation and Self-Test

Make sure that the WDM equipment is powered on normally and perform self-checks to ensure that all components of the equipment are working properly.

Step 2: Interface Configuration

In the WDM interface view, configure the optical parameters of the interface to connect the physical layer of the interfaces at both ends.

This usually includes configuring optical parameters such as FEC (forward error correction) mode and TTI (path tracing identification).

FEC is mainly used to correct data errors. TTI is used to identify the source and sink sites of each fiber connection to prevent misconnections.

Step 3: System Configuration

Execute a command to enter the system view. For example, execute the system-view command.

Step 4: Business Configuration

After the physical layer is connected, configure the corresponding business parameters according to business requirements.

Step 5: Performance Monitoring and Maintenance

Regularly monitor the performance of WDM equipment to check its working status and transmission quality.

Carry out necessary maintenance operations based on the monitoring results. Such as cleaning interfaces and replacing damaged parts.

Step 6: Security Management

Ensure the safe operation of WDM equipment and prevent unauthorized access and operations.

Conduct regular safety inspections on equipment to ensure it complies with relevant safety standards and regulations.


Although Ethernet Over SONET, Packet Over SONET and WDM technologies each have their own advantages. SDH and PDH technologies still play an irreplaceable role in data transmission and network communications.

Post time:2024-05-01


Lomoveishiy – Finland

I needed those to connect my PC on the third floor to have internet access in that room, and ISP installed their modem on the first floor only. After dropping fiber patch cables, plugged in all cables into these media converters at both sides, and link came up instantly. Was much easier than I thought!

Raymond – USA

Great experience – units worked straight out of the box – just needed plug in cables and we were done. I also like the possibility to enable jumbo frames, while we do not have a need for this feature at the current moment it’s great to have this option.

Recent Blog

View More+

Leave Your Message