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As the residential subscriber becomes more sophisticated, cable operators seek unique technology that not only engages their most advanced customers, but serves their entire customer base with improved troubleshooting and predictive support tools.

Virtualization is already deployed for many business customers today. In these deployments, operators have been able to simplify the physical platforms deployed to the customer and have been successful in offering self-care portals for key products such as voice Over IP (VoIP), load balancing, and security.

As much as the early work in virtualization for commercial business customers has been a success, the marriage of virtualization into the residential cable subscriber premises is not a straight line. Predicting the future continues to identify multiple paths.

What Problem Does Virtualization Address?

The first question is, “What problem does virtualization seek to solve for the residential customer?” The answer really depends on who you ask. For some operators, virtualization offers a freedom from the confinement of a vendor feature list locked up in firmware. Thus, virtualization enables new services and product offerings. For others, the urgent need to help customers connect an increasing variety of device types is the most pressing issue to solve. Always high on the priority list is the introduction of advanced WiFi controls and the opportunity to redefine the current state of the self-care portal experience for customers.

To support these concepts behind the scenes, a number of fundamental pieces are on the move. Residential subscriber portals have been introduced to the industry through Broadband Forum TR-069 Auto Configuration Server (ACS) technologies. For these, the ACS platform is the engine supporting the customer self-care portals that enable operators to deploy a multi-vendor variety of CPE devices while maintaining consistent quality of experience (QoE).

Extending this scenario to when a virtualized subscriber is deployed, the ACS is often used at a deeper level than simply changing WiFi parameters. A virtual CPE (vCPE) can be thought of as a portal application leveraging an ACS for the physical on-premises, hardware-dependent actions.

Two Models

A significant enabler of vCPE is the changes in the logical network topology. At a high level, two models exist: one model where all Layer 2 and IP Layer 3 services are tunneled into a virtual CPE concentrator, essentially a cloud in the operator network cloud, and another model where this topology is split in a hybrid fashion between the operator network cloud and the physical CPE gateway.

In the first model, the customer gateway encapsulates one or multiple tunnels directing LAN and WiFi presentations to the virtual CPE cloud. As a result, the virtual CPE is now effectively the “gateway” for the local residential network.

In the second model, the customer gateway encapsulates multiple tunnels toward the operator cloud network, in addition to supporting some locally isolated software within the gateway. In this model, the “gateway” in terms of common IP services may live simultaneously in two physical locations, such as DHCP running locally while firewall services run from within the operator cloud network.

In both models, the ability to enhance residential network discovery and extend subscriber self-care functionality exists – but the models have different financial costs. The first suggests many existing DOCSIS devices could be repurposed with all services run from the operator cloud. In this cost model, the imperative is on scale in the cloud compute platforms.

The hybrid model requires a more advanced customer gateway. It could be argued that the greatest flexibility comes from compute resources being used in both the operator cloud and the customer premises. But while this offers the most consistent service in the long term, it also likely represents the larger total cost.

For the field technician, configuring or troubleshooting services for a virtual residential subscriber may feel quite different than doing so for a subscriber in the traditional model. Typically, any browsing to the local web page is returned from the operator self-care portal located elsewhere, and troubleshooting the availability of services may now involve understanding which functions operate locally – if any – and which run within the operator virtual CPE cloud. This virtualized model means a need for more intimate knowledge of the subscriber setup.

For the operations and engineering teams, exposing service assurance metrics regardless of vCPE deployment model is fundamental. The health and availability of a subscriber experience can no longer be primarily measured by the data returned from cable modem physical layer objects. Trap and monitor points for each subscriber's set of application services and the network dependencies they carry is vital to understanding the network.

Predicting the next year in residential vCPE includes recognizing these key financial and technical aspects of an emerging delivery architecture. Both operating models of vCPE are valuable, for different reasons, and regardless of the approach, a large concentration on installation, troubleshooting, and monitoring at scale will be required to move vCPE into the residential service stage in 2017.

Chris Busch is chief innovation officer at Incognito Software Systems.

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