NICE -- TM Forum Live! -- For all the admitted enthusiasm about network functions virtualization here, there is also a growing number of concerns being raised here, the most recent being that of how liability is shared for service failures or outages once multiple software-based functions run on logically separate hardware.
In multiple sessions on NFV, service providers have admitted there is not yet a clear understanding of how liability will be shared and how service level agreements (SLA) will be designed, delivered, and guaranteed once they move off purpose-built telecom hardware onto more agile virtualized network gear.
"When you have different providers providing virtual network functions on the same NFV infrastructure, you need to take into account the different roles," said Laurent Leboucher, VP of APIs and Digital Ecosystems for Orange (NYSE: FTE) in a Wednesday morning panel. "When something goes wrong, who is responsible? This is a new source of complexity, making fault management more difficult. We will need to manage this complexity."
The overall role of managing VNFs will fall to the network orchestrator, says Caroline Chappell, senior analyst with Heavy Reading and chair of the session at which Leboucher was speaking. "The orchestrator will have to understand the implications of where it places specific VNFs."
Those decisions will be based on factors such as liability, security, network performance and other business issues, all of which now will typically become part of the contract process. A company providing a VNF will also provide requirements for running it. Those requirements become part of the policies put in place with the network orchestrator, Chappell says. As for the hardware running the virtual functions, it is part of the NFV infrastructure, which is what provides SLAs up to those VNFs, she says.
"The service provider will have to have a well-mapped, well-managed NFV infrastructure," she adds. The hope is the industry can get a common approach to the NFV infrastructure that can be trusted.
"The liability then lies with whoever runs the NFV infrastructure, and that can be an operator or a systems integrator," Chappell says. "The role of systems integrators could change under virtualization."
The Heavy Reading analyst says the challenge will be to be able to abstract the virtual infrastructure at each layer of the network, which could potentially lead to separate SLAs and performance requirements for individual layers, creating the need for understanding who is responsible for what.
It's one more layer of complexity for the technology ultimately being counted on to simplify the network operator's efforts to bring service to market more quickly.
— Carol Wilson, Editor-at-Large, Light Reading