Carrier Ethernet (CE) services include retail and wholesale services for the business, mobile and residential market segments. Curr­en­tly, these market segments are embracing the cloud experience in a big way and requesting on-demand and flexible services from their service providers. Network function virtualisation (NFV), when used with CE infrastructure, can deliver agile services with added service-level agreement (SLA) performance assurances for critical business applications. Adding a virtualisation layer to CE 2.0 services and infrastructure helps in the evolution and enhancement of operator service offerings through new deployment models. A look at the deployment options and benefits of combining CE 2.0 and NFV…

Customer premises deployment options

Many service providers are looking to virtualise customer premises equipment (CPE) functions as a means to offer on-demand, virtual network services in existing and new markets. To this end, several deployment models are being explored such as physical network interface devices (NIDs), virtual CPE (vCPE) and hybrid implementation. Under the physical NID model, all CE functions are performed in NIDs at the customer premises while additional service functions such as a routers, firewalls, etc. are implemented as VNFs using the centralised deployment model at the service provider’s point of presence (PoP). As part of the vCPE deployment option, CE functionality (including service demarcation) and additional functions and services for example, routers, firewalls, etc. are implemented as VNFs running on a commercial off-the-shelf (COTS) compute platform deployed at the customer premises using the decentralised deployment mo­del. A vCPE4 is designed to replace and move some or all CPE functions to a COTS compute platform at the customer premises. This dep­loyment option repla­ces multiple appliances at the customer premises with a single platform to deliver virtual network services. Under hybrid implementation, some or all CE functionality (including service demarcation) are implemented as physical network functions while additional functions and services are implemented as VNFs similar to the case of vCPE deployment.

Leveraging the combined benefits

  • Enhancing existing CE services with NFV – Network operators that offer CE 2.0 services or partner with third-party CE 2.0 access providers can benefit from implementing NFV to complement their CE 2.0 services. CE 2.0 provides the baseline connectivity service and virtual network services are layered upon it using NFV technologies. NFV, combined with CE and LSO, provides service agility and rapid service innovation, which help create differentiation and revenue generating opportunities. The VNFs may be installed at customer premises using the decentralised deployment model or within the service provider’s PoP using the centralised or distributed deployment models.
  • Assured CE connectivity with centralised VNFs – Enterprises and small-medium businesses (SMBs) are increasingly adopting cloud services. Connecti­vity to public cloud providers is mostly achieved using internet connections, which may not provide sufficient service performance and reliability. This provides an area of opportunity for service providers as they can leverage NFV by implementing VNFs within their PoP. These VNFs may include firewall and other L4-L7 functions that can be combined with the CE connectivity service to deliver the assured performance required by enterprises and SMBs when connecting to cloud services. Load balancer VNFs can be used to increase availability.
  • Virtualisation use case for off-net e-access services – Two service demarcations are required when providing service operations, administration and maintenance (OAM) fault management and performance measurements for SLAs – one for the e-access provider and one for the Ethernet service provider. The challenge with this approach is that Ethernet service providers may not have installation personnel in the region to deploy and install physical NIDs at the customer premises. In such a scenario, it has to rely on the e-access provider to perform this function as a proxy. Two different future mode of operations (FMO) virtualisation paths using NFV technologies can address this issue by virtualising all or some of the NID functions. These FMO approaches benefit both network operators. The e-access provider can sell the service demarcation functionality to the Ethernet service provider and the Ethernet service provider can create new revenue opportunities and service differentiation. The Ethernet service provider can deliver better service OAM to off-net locations that are part of a multi-site VPN, resulting in better SLAs and service differentiation. Additionally, with the VNF-based approach, both providers have the opportunity to add new functions and services beyond the foundatio­nal CE service demarcation functionality.

In sum

CE provides the foundational connectivity for performance and security assurance, while NFV provides the agility to layer additional services onto the CE 2.0 network. The combination of the two will help service providers offer, enhance and expand their offerings through new and innovative services.

Based on a white paper, “Carrier Ethernet and NFV” by MEF