Infonetics Research has interviewed global service providers regarding their plans for software-defined networking (SDN) and network functions virtualisation (NFV). Gazettabyte asked Michael Howard, co-founder and principal analyst, carrier networks, about Infonetics' findings.
"Data centres are simple when compared to carrier networks"
Michael Howard, Infonetics Research
What is it about SDN and NFV - technologies still in their infancy - that already convinces 86 percent of the operators to deploy the technologies in their optical transport networks?
Michael H: Operators have a universal draw to SDN and NFV for two basic reasons:
1. They want to accelerate revenue by reducing the time to new services and applications.
2. They have operational drivers, of which there are also two parts:
- Carriers expect software-defined networks to give them a single view across multiple vendor equipment, network layers and equipment types for mobile backhaul, consumer digital subscriber line (DSL), passive optical network (PON), optical transport, routers, mobile core and Ethernet access. This global view will allow them to provision, monitor and deliver service-level agreements while controlling services, virtual networks and traffic flows in an easier, more flexible and automated way.
- An additional function possible with such a global view across the multi-vendor network is that traffic can be monitored and re-distributed along pathways to make best use of the network. In this way, the network can run 'hotter' and thereby require less equipment, saving capital expenditure (CapEx).
Optical transport networks have a history of being engineered to effect predictable flows on transport arteries and backbones. Many operators have deployed, or have been experimenting with, GMPLS (Generalized Multi-Protocol Label-Switching) and vendor control planes. So it is natural for them to want to bring this industry standard method of deploying an SDN control plane over the usually multi-vendor transport network.
In our conversations - independent of our survey - we find that several operators believe the biggest bang for the SDN buck is to use SDN for single control plane over multi-layer data - router, Ethernet - and the optical transport network.
"The virtualisation of data centre networks has inspired operators who want to apply the same general principles to their oh-so-much-more complex networks"
Early use of SDN has been in the data centre. How will the technologies benefit networks more generally and optical transport in particular?
SDNs were developed initially to solve the operational problems of un-automated networks. That is to say, slow human labour-intensive network changes required by the automated hypervisor as it moves, adds and changes virtual machines across servers that may be in the same data centre or in multiple data centres.
The virtualisation of data centre networks has inspired operators who want to apply the same general principles to their oh-so-much-more complex networks. Data centres are simple when compared to carrier networks. Data centres are basically large numbers of servers connected by Ethernet LANs and virtual LANs with some router separations of the LANs connecting servers.
"It will be many years before SDNs-NFV will be deployed in major parts of a carrier network"
Service provider networks are a set of many different types of networks including consumer broadband, business virtual private networks, optical transport, access/ aggregation Ethernet and router networks, mobile core and mobile backhaul. Each of these comprises multiple layers and almost certainly involves multiple vendor equipment. This explains why operators are starting their SDN-NFV investigations with small network segments which we call 'contained domains'. It will be many years before SDNs-NFV will be deployed in major parts of a carrier network.
You mention small SDN and NFV deployments. What will these early applications look like?
Our survey respondents indicated that intra-datacentre, inter-datacentre, cloud services, and content delivery networks (CDNs) will be the first to be deployed by the end of 2014. Other areas targeted longer term are optical transport, mobile packet core, IP Multimedia Subsystem, and more.
Was there a finding that struck you as significant or surprising?
Yes. A lot of current industry buzz is about optical transport networks, making me think that we'd see SDNs deployed soon. But what we heard from operators is that optical transport networks are further out in their deployment plans. This makes sense in that the Open Networking Foundation working group for transport networks has just recently got their standardisation efforts going, which usually takes a couple of years.
You say that it will be years before large parts or a whole network will be SDN-controlled. What are the main challenges here regarding SDN and will they ever control a whole network?
As I said earlier, carrier networks are complex beasts, and they are carrying revenue-generating services that cannot be risked by deployment of a new set of technologies that make fundamental changes to the way networks operate.
A major problem yet to be resolved or even addressed much by the industry is how to add SDN control planes to the router-controlled network that uses the MPLS control plane. SDN and MPLS control planes must cooperate or be coordinated in some way since they both control the same network equipment-not an easy problem, and probably the thorniest of all challenges to deploy SDNs and NFV.
The study participants rated CDNs, IP multimedia subsystem (IMS), and virtual routers/ security gateways as the main NFV applications. At least two of these segments already use servers so just how impactful will NFV be for operators?
Many operators see that they can deploy NFV in a much simpler way than deploying control plane changes involved with SDNs.
Many network functions have already been virtualised, that is software-only versions are available, and many more are under development. But these are individual vendor developments, not done according to any industry standards. This means that NFV - network functions run on servers rather than on specialised network equipment like firewalls, intrusion prevention/ intrusion detection systems, Evolved Packet Core hardware - is already in motion.
The formalisation of NFV by the carrier-driven ETSI standards group is underway, developing recommendations and standards so that these virtualised network functions can be deployed in a standardised way.
Infonetics interviewed purchase-decision makers at 21 incumbent, competitive and independent wireless operators from EMEA (Europe, Middle East, Africa), Asia Pacific and North America that have evaluated SDN projects or plan to do so. The carriers represent over half (53 percent) of the world's telecom revenue and CapEx.