From TDM to MPLS-TP: A Guide to Network Migration; Prepare for IEC 61850 GOOSE

GOOSE (Generic Object Oriented Substation Event) messages are used for fast and reliable communication between intelligent electronic devices (IEDs) in power system substations. To support GOOSE messaging, the network infrastructure needs to meet certain requirements to ensure fast and reliable delivery of messages this needs to be taken in consideration when planning a migration. Switching from TDM to MPLS-TP can give considerable benefits. However, careful planning and execution are required to guarantee that the transfer is effective and does not disrupt vital processes.

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Low Latency: In order to guarantee that GOOSE messages are delivered within a certain amount of time, the network must have low latency. GOOSE communications typically have a latency requirement of less than 3ms.

The term "latency" describes the length of time it takes for a message to travel across a network from one device to another. The power system may suffer significant effects if a GOOSE notification is missed or delayed.

The network architecture must be planned to reduce message delivery delays in order to meet the low latency requirements for GOOSE messaging. Because MPLS-TP uses label-switching to deliver quick and effective packet forwarding, it is a good fit for GOOSE messaging. As a result, processing time and latency are decreased.

High Reliability: In order to guarantee that GOOSE communications are delivered without loss or delay, the network must be extremely dependable. Since GOOSE communications are essential for performing crucial power system protection and control tasks, their loss or delay may have detrimental effects.

The ability of the network to send messages without interruption or delay is referred to as reliability. In order to reduce the possibility of packet loss or delay, network infrastructure must be constructed to match the high reliability criteria for GOOSE communications. Because it includes protection and restoration techniques like Bidirectional Forwarding Detection, which can quickly switch traffic to a backup path in the case of a failure, MPLS-TP is well suited for GOOSE messaging. In addition, traffic engineering and label-switching can help to reduce congestion and packet loss.

For critical applications in a substation, employing HSR or PRP with GOOSE messages provides a highly reliable and fault-tolerant communication network. The redundancy offered by HSR or PRP guarantees that the GOOSE messages will continue to be sent and received even in the case of a network failure or equipment malfunction, as well as that critical operations will continue to be carried out.

Scalability: As the power system grows and changes, the network must be scalable to handle an increasing volume of devices and communications. For the network to be able to achieve the low latency, high reliability, and deterministic behavior criteria of GOOSE messaging over time, this is crucial.

The ability of the network to manage growing traffic loads and devices?without affecting performance or adding too much delay is referred to as scalability. Network infrastructure must be planned to support future increases in traffic and device counts in order to meet the scalability requirements for GOOSE messaging. Because it provides traffic engineering, which enables network administrators to optimize network resources and expand network capacity as necessary, MPLS-TP is well suited for GOOSE messaging. Moreover, MPLS-TP offers hierarchical network architectures, which might reduce the adverse effects of network expansion on reliability and latency.

Multicast Support: GOOSE messages are typically multicast messages, which means that they are sent to multiple recipients at the same time. The network must support multicast traffic to enable the delivery of GOOSE messages.

Segregated LSPs efficiently transport multicast traffic. Networks can achieve more efficient and scalable multicast forwarding by employing MPLS labels to control multicast traffic, eliminating the need for sophisticated protocols or group administration.

Support for Encryption: Because GOOSE messages contain sensitive data or orders that cannot be altered or intercepted, encryption may occasionally be necessary to safeguard their confidentiality and integrity.

Encryption can provide additional security for GOOSE messages by protecting them from unauthorized access, interception, and tampering. Man-in-the-middle attacks, which happen when an attacker intercepts and alters GOOSE signals in transit, can also be defended against via encryption. If encryption is used, it is critical to ensure that the encryption mechanism is appropriate for the power system automation and control network's specific requirements. Some encryption mechanisms, for example, may introduce latency or overhead, which may impact the real-time nature of GOOSE messages.

In short, the requirements of low latency, high reliability, deterministic behavior, scalability, multicast support and encryption, should be taken into account while designing and implementing a network for GOOSE messaging. Because to its support for label-switching, traffic engineering, protection and restoration mechanisms, and hierarchical network architectures, MPLS-TP is well suited for fulfilling these criteria. Network administrators may make sure that their networks deliver the high-performance and dependability required for vital power system protection and control functions by leveraging these characteristics.