According to Coriant, there is a lack of efficient interworking in multivendor transport networks, so the company announced new features to one of its software defined networking (SDN) controllers on Thursday to address the problem.

Coriant’s Transcend Transport Controller has been around for about a year now. It spans the optical layer up to Layer 2 switching. (Coriant’s other controller reaches up to Layer 3 but does not handle the optical network.)

Coriant is now enabling support for the Restconf interface and YANG data modeling language. These provide an open API framework for synchronization between IP - and optical-layer SDN controllers.

“This part of the features is key to new service deployment because this interface connects the transport SDN with higher network layers,” says Harald Bock, CTO of technology strategy for Coriant. “It’s important because the different layers need to be aware of each other. This is interworking layer 2 to what you could call layer 2.5,” says Bock.

Bock says without this upgrade, the higher layer has to find out by itself what connectivity it has, which is not very efficient. It also isn’t very resilient because in order to project traffic, it needs to know what connections it has.

“The YANG model is really the key enhancement,” he says.

Another new feature in the controller assures the best path for network traffic by detecting optical impairments, path restrictions, and specific service-defined constraints such as latency.

Finally, the controller now provides enhanced network slicing so users can virtually apportion segments of the network across multiple products and layers to satisfy the requirements of a particular end-user. For example, network slicing can be used to partition services for a retail carrier in a wholesale environment or a large enterprise.

The new features of the Transcend Transport Controller are in customer trials.