One of the bigger debates to emerge at the Mobile World Congress 2018 conference this week is the degree to which network service providers will be relying on virtual appliances rather than containers to implement network functions virtualization (NFV).
Service providers of all size are rushing to embrace network virtualization to replace physical network appliances that today must be managed manually. That transition has been extended to the point now where many service providers are now trying to decide between transforming a network function into a virtual appliance based on a hypervisor or rely on containers to achieve the same goal.
This week Metaswitch, a provider of cloud-native networking software, published a white paper in collaboration with Telenor, a provider of mobile networking services, to help network service providers determine when best to apply containers instead of virtual appliances. The white paper details the underlying architecture the two companies employed to create a proof-of-concept instance of an NFV platform based on containers running on Intel servers.
Pål Grønsund, senior research scientist at Telenor, says that carrier expects to make use of both virtual appliances and containers to deliver networking services in a much more agile manner. The challenge now is deciding when to employ a virtual appliance rather than making use of lighter-weight containers. Factors that will determine which path to take include the level of isolation and performance attributes of the network function that is being virtualized, says Grønsund.
In general, network service providers are still in the early stages of modernizing their underlying infrastructure. AT&T and Verizon have lead the charge as part of an effort to flexibly deliver next-generation 5G networking services based on OpenStack. But in the time since those efforts began, container software such as Docker and container orchestration software such as Kubernetes have substantially matured. AT&T, for example, is making using of containers to build some classes of NFV software. However, in cases where performance or density is of premium concern, it’s expected many service providers will opt to deploy containers on bare-metal servers rather than on top of a hypervisor.
Steve Gleave, vice president of marketing for Metaswitch, says that as other network providers rush to catch up, many of them are discovering the potential of containers as alternative means for building network functions. Metaswitch already makes extensive use of containers to build its networking platform and this week announced it will add NFV orchestration software from Cloudify to its core platform. At the same time, Hewlett-Packard Enterprise (HPE) announced it will resell the Metaswitch platform within the NFV platform it provides telecommunications carriers.
The biggest issue facing many of the providers of networking equipment is that most of them have spent years now transforming their core software assets into a virtual machine, only to discover they may need to make those functions available as a set of microservices based on containers. In many cases, their investments in developing virtual appliances may have been wasted.
Whatever the outcome, the one thing clear is that advances in network virtualization are now coming fast and furious. Containers as a technology may have caught many network service providers off-guard. But the days when network services took weeks to months to provision are now officially over.