Ensuring Network Security: Six Common DWDM Solutions

Updated on Jul 16, 2020 by

DWDM (Dense Wavelength Division Multiplexing) is a vital optical technology that plays a crucial role in significantly boosting network bandwidth, particularly within existing optical fiber backbone systems. By concurrently transmitting multiple light signal wavelengths, it optimizes the transmission capacity of optical fibers. With its impressive capacity, resilience, and flexibility, DWDM has emerged as the preferred backbone solution for networks and extensive data transmissions. However, as network landscapes evolve, challenges such as fiber malfunctions and interruptions in transmission lines can have a severe impact on communication and commerce. Hence, the establishment of secure DWDM networks is paramount. If you want to delve deeper into DWDM technology, you can check out this article: Complete Analysis on DWDM Technology. Additionally, in this context, we'll explore six common DWDM solutions aimed at fortifying the security of optical networks, highlighting the critical role of DWDM in networking.

Six Common DWDM Solutions for Secured Networks

To minimize the network risks and cater to the network monitoring, here lists six DWDM transport network solutions, that is OLP, OPD, OPM, RNP, OCM and complete protection. The following sample DWDM solutions all adopt 40CH DWDM Mux/Demux with 10G DWDM 80 km transceivers, and G.652 fiber grade by default. In the point-to-point network, 80km distance is designed with the fiber attenuation of 0.25dB per kilometer. In the three-point ring network, the distance between every two sites is 40 km.

Optical Line Protection (OLP)

OLP is a device used to protect optical network transmission lines. It enables optical power monitoring and automatic switching of optical lines. In optical communication networks, OLP continuously monitors the optical power of both the main fiber and the standby fiber in real-time. When the current optical power of the fiber falls below a pre-set switching threshold, an alarm is triggered, and traffic is automatically switched to the standby fiber within 15ms to protect the optical transmission system line. It is important to note that the lengths of the main and standby links must be similar to ensure optimal performance. Additionally, there are different types of OLP devices available, with the most commonly used being OLP 1:1 and OLP 1+1. These variations offer flexibility in designing and implementing optical network protection strategies.

The following are the applications of OLP:

  • OLP plays a vital role in backbone network protection, especially in scenarios with ample dark fibers. It ensures network stability and reliability by monitoring fiber optic power and offering redundancy through redundant fiber cores. In the event of main fiber failure, OLP seamlessly switches to the standby fiber core, maintaining uninterrupted network services without manual intervention.

  • Given the intricacies and potential signal attenuation of long-distance transmission lines, any deviation in optical power can result in line disruptions. Hence, OLP finds extensive use in long-distance transmission scenarios. Equipped with high-precision sensors and real-time feedback mechanisms, OLP continuously monitors optical power across both main and standby fibers. Upon detecting any abnormal decrease in optical power, the controller swiftly triggers an alarm and initiates automatic switching. This ensures uninterrupted business operations on long-distance transmission lines.

optical line protection

Figure 1:OLP DWDM Solution Diagram

Optical Power Detection (OPD)

OPD is highly precise, ideal for monitoring optical systems with accuracy and broad capabilities. It measures losses in optical fibers, cables, and passive devices, aiding in the maintenance of communication systems. Like an optical power meter, OPD mainly uses 1310nm/1550nm light for real-time fiber monitoring, identifying failures swiftly. This enhances DWDM stability, maintenance quality, and reduces user losses. However, OPD cannot distinguish faults between fibers and equipment. In such cases, OTDR can evaluate intermediate links for faults, analyzing signal transmission to detect issues like fiber breaks. If OTDR tests show no anomalies, equipment may be the source of the fault.

The following are the applications of OPD:

  • In a data center environment, OPD monitors optical power in fibers and cables, allowing real-time detection of signal transmission status. Equipped with highly accurate monitoring capabilities, OPD ensures continuous monitoring of optical equipment such as switches, routers, and converters. It swiftly identifies issues like signal attenuation, fiber breaks, or loose connectors by analyzing optical power variations.

  • In WANs, OPD monitors optical power levels in fibers and cables over long distances, maintaining network reliability and performance. Similarly, in MANs, OPD monitors optical power to facilitate seamless data transmission between different locations within the metropolitan area. OPD's ability to monitor optical power ensures the reliability and efficiency of data transmission across network infrastructures.

optical power detection

Figure 2:OPD DWDM Solution Diagram

Optical Performance Monitoring (OPM)

In DWDM networks, OPM is essential for consistently monitoring data channel quality by evaluating optical characteristics in real-time. They ensure precise switching in reconfigurable optical add-drop multiplexers, dynamically adjust optical amplifier gain, and issue system alerts for any deviations in optical channels. However, long-haul DWDM transmission encounters challenges, particularly signal attenuation in lengthy fiber optic cables. To uphold top-notch optical signals and data integrity, strategically deploying OPMs along routes is essential. It's important to note that the current application of OPM is restricted to the C-band spectrum. It's important to note that while the current application of Optical Power Meter (OPM) is restricted to the C-band spectrum, other spectral bands can be monitored by OSA.

The following are the applications of OPM:

  • In DWDM networks designed for long-distance transmission, OPMs continuously monitor the quality of data channels by evaluating optical characteristics in real-time. They ensure precise switching in reconfigurable optical add-drop multiplexers and dynamically adjust optical amplifier gain. Additionally, they promptly issue system alerts and monitor any deviations in optical channels. Considering challenges like signal attenuation that lengthy fiber optic cables may encounter, strategically deploying OPMs along routes becomes paramount.

optical performance monitoring

Figure 3:OPM DWDM Solution Diagram

Optical Channel Monitor (OCM)

OCM is crucial in optical network systems, ensuring real-time monitoring of both wavelength and power of optical signals for smooth and efficient network operations. With its capability to support multiple channels, the OCM offers continuous monitoring, guaranteeing signal quality, stability, and strength to facilitate reliable network transmissions. Additionally, the OCM facilitates remote monitoring of DWDM wavelengths on optical fibers, enhancing monitoring efficiency and effectiveness. The latest release from FS, the D7000 Series OCM, elevates monitoring capabilities by enabling the monitoring of individual channels. Leveraging built-in Optical Switches (OSW), it enables swift channel switching, facilitating efficient monitoring of multiple channels within a short timeframe. This advancement substantially enhances monitoring efficiency and accuracy, ensuring optimal network performance. Moreover, the D7000 Series OCM can be seamlessly connected to 40-channel MUX/DEMUX monitoring ports, detecting wavelengths in the range of 1528~1568nm, further extending its monitoring capabilities and compatibility.

The following are the applications of OCM:

  • The OCM plays a significant role in facilitating the transmission of optical signals within and between data centers. By continuously monitoring wavelength and power in real-time, the OCM ensures stable signal transmission and swiftly detects and resolves potential signal anomalies or wavelength drift issues. Additionally, FS OCM boasts low power consumption, compact size, and seamless integration with other devices, offering flexible deployment in data center environments. This facilitates efficient, reliable, and secure optical signal transmission, providing a stable and dependable foundation for data center interconnectivity.

  • Reliable optical signal transmission in metropolitan networks is crucial. The OCM plays a key role by monitoring signal quality, detecting faults, and improving network performance. With real-time tracking of wavelength stability and power levels, the OCM ensures dependable data transmission and helps operations teams swiftly address signal issues, enhancing overall network efficiency. Additionally, it provides critical data for route planning and resource management, ensuring seamless transmission and maximizing network utilization.

Common DWDM Solutions for A Secured Network

Figure 4:OCM DWDM Solution Diagram

Ring Network Protection (RNP)

In ring network setups, incorporating DWDM protection into the shared optical channel architecture offers a cost-effective and secure solution. For example, in a three-point ring network, services can seamlessly shift between different sites to address faults like optical fiber breakage. This specialized protection system offers greater robustness compared to traditional methods. By using second-layer ring protection, it effectively minimizes service disruptions caused by internal fiber breakage, ensuring continuous business operations. If optical fiber breakage occurs between two sites, data can be rerouted to the destination, enabling uninterrupted business operations. The architecture, comprising two or more devices, employs second-layer protocols to smoothly manage fault transfers for protected traffic, avoiding interruptions. Additionally, it includes a data ring to further reduce service interruptions and incorporates built-in redundancy to effectively prevent downtime.

The following are the applications of RNP:

  • In enterprise internal networks, ring network protection ensures seamless data switching and backup using a ring-shaped topology, guaranteeing continuity and stability during network interruptions. With each node forming a ring within the network, data can flow along this loop. Should a network interruption occur, ring network protection automatically redirects data along an alternate path, ensuring uninterrupted business operations and upholding operational continuity and stability for the enterprise.

  • In wide area networks (WANs), ring network protection technology is vital for setting up expansive transmission systems on a large scale. By utilizing a ring-shaped topology, it streamlines network connectivity and facilitates seamless data transmission across various geographic regions. This innovative technology not only improves the efficiency and reliability of WANs but also ensures the utmost security and integrity of transmitted data.

ring network protection

Figure 5:RNP DWDM Solution Diagram

Complete Protection

It seems irrational to add another identical configuration to the solution, particularly with regard to the DWDM system. However, it is highly applicable when the budget allows for excess fibers. The purpose is to ensure normal operations by swiftly switching the broken link onto the excess allocated capacity within a certain timeframe. Utilizing the redundant portion of the network to provide additional capacity in case of failure or fault is viable, especially in point-to-point DWDM solutions. This is crucial as equipment, fiber, or node failures are not uncommon and can sometimes result in significant revenue losses.

The following are the applications of Complete Protection:

  • In telecommunications, phone and data services are crucial for communication. This is especially true in the core network, particularly in large-scale fiber optic networks handling heavy traffic. Even during network failures, like fiber cuts, Complete Protection ensures service continues. By using extra network capacity to switch data seamlessly, it keeps operations running smoothly, allowing users to make calls and send data without interruption.

  • In financial trading networks, the reliability and continuity of networks for exchanges and banking systems are paramount. In the highly competitive and dynamic financial markets, trading systems must execute orders and transfer funds at lightning speed. Complete Protection ensures that even during network failures, trading systems can continue operating. By leveraging additional network capacity to provide backup paths, it ensures that exchanges and banks can process transactions at all times, maintaining the liquidity and stability of the financial markets.

complete protection


Figure 6:Complete Protection DWDM Solution Diagram


In conclusion, as networks shift towards increased automation and reduced dependence on manual processes, it's crucial to implement robust safeguards for detecting and mitigating security vulnerabilities. FS provides dedicated DWDM solutions, including OLP, OPM, OCM, and OPD, each offering numerous benefits, including efficient dwdm troubleshooting capabilities. These solutions not only minimize network errors but also ensure more reliable connectivity, thereby meeting future regulatory requirements. Considering potential future technological trends, it's clear that the security of DWDM equipment will remain a vital aspect of network infrastructure. Therefore, emphasizing the importance of security measures within DWDM deployments is a proactive approach to addressing evolving security challenges and maintaining network integrity.

You might be interested in