LONDON -- OSS in the Era of SDN and NFV -- BT has been forced to address the lack of conformity between vendors developing SDN and NFV technologies through a program of in-house training and dramatic cultural change, said the operator's chief portfolio architect here in London this morning.
Martin Tatham, chief portfolio architect at BT Global Services, said he was disappointed that vendors had failed to come up with a "clean set of network APIs [application programming interfaces]" that would make the introduction of emerging SDN and NFV technologies more straightforward.
The resulting complexity is at odds with the original industry goals of simplifying network design through the use of software and virtualization technologies, and could negate the benefits that telcos expect to realize through network transformation.
Tatham told attendees at today's Light Reading event that BT Group plc (NYSE: BT; London: BTA) had run into a number of challenges in the service design and orchestration areas.
"The ideal would be to have well-structured Netconf and YANG interfaces. That would be a joy but we are so far off that," he said, referring to the configuration and data modeling languages that underpin SDN and NFV technologies. "We have to manage the differences between different technologies and that is where we are then using an annotated YANG approach."
Tatham explained to attendees that BT has been training a substantial number of network designers to build YANG models so that it can address the "growing diversity" it sees on the vendor side.
Describing the problem in more detail, Tatham said that -- despite vendor efforts on conformity and interoperability -- SD-WAN products from suppliers such as Nokia's Nuage and Cisco had turned out to be quite different.
"You take two SD-WAN solutions that on paper look identical from an architecture point of view, in terms of endpoints and gateways and the control layer and the management layer … and they are massively different in terms of how notifications work, the way to do device level configuration," said Tatham.
But overcoming that problem by training in-house staff on YANG has not been easy, said the BT executive.
Asked how BT had managed the necessary cultural change, Tatham replied: "Very painfully. We found it wasn't moving fast enough and had to crunch the organization. Some engineers make it and some don't."
With the emergence of hybrid networks, in which some functions are virtualized and some are physical, there has been an explosion in the number of service scenarios that BT needs to address. That has given the operator an even greater need for data modeling expertise, said Tatham.
"If you don't have a good way of modeling those [scenarios] with a suitable layer of abstraction, you are in deep trouble," he said. "From an operational point of view, if you can't get modeling technologies into the hands of the right people who understand the network, then your agility crashes."
Operators including BT have long seen SDN and NFV technologies as a way of slashing costs and speeding up the introduction of new services. Service providers fear they will concede even more ground to so-called over-the-top (OTT) players unless they can acquire the same degree of "agility."
In a morning presentation at today's event, Heavy Reading senior analyst James Crawshaw noted that OTT companies continue to put pressure on telcos' average revenues per user, and that telco margins are declining as volumes of Internet traffic skyrocket.
Tatham urged vendors to speed up the development of monitoring and analytics technologies, which could support future network management and automation efforts within the service provider community. "This is the biggest area of value add and we want to see progress from vendors," he told attendees.
— Iain Morris, News Editor, Light Reading