Virtualized Resource

Description

A Virtualized Resource (VR) is a key concept within the 3GPP management framework, particularly for the management of virtualized network functions (VNFs) in a cloud-native environment. It represents a logical abstraction of a physical resource, such as a CPU core, a block of memory, a storage volume, or a virtual network interface card (vNIC). These abstractions are created and managed by a virtualization layer (e.g., a hypervisor or container runtime) on top of physical hardware. The 3GPP management system, defined in specifications like 28.520 (Management and Orchestration, MANO), interacts with VRs to allocate, monitor, and orchestrate them for the purpose of instantiating and scaling network functions.

The architecture involves several key entities. The Virtualized Infrastructure Manager (VIM) is responsible for controlling and managing the NFVI (Network Functions Virtualization Infrastructure) compute, storage, and network resources. The VIM exposes these resources as VRs. The NFV Orchestrator (NFVO) and VNF Manager (VNFM) then use these VRs, described in a VNF Descriptor (VNFD), to deploy VNFs. A VNFD defines the VNF's requirements in terms of Virtualized Compute, Storage, and Network Resources (Vnfc, VnfStorage, VnfVirtualLink). During instantiation, the MANO system maps these requirements to available VRs on the infrastructure, creating the necessary virtual machines (VMs) or containers with the specified CPU, memory, and network connectivity.

VRs are dynamic and elastic. Their lifecycle (creation, modification, termination) is managed through standardized interfaces, such as the Or-Vi reference point between the NFVO and VIM. Monitoring of VR performance metrics (e.g., CPU utilization, memory usage, I/O rates) is also standardized, allowing the MANO system to perform automated scaling actions. For example, if a VNF experiences high load, the VNFM can request additional virtualized compute resources (more VRs) from the VIM via the NFVO, leading to the scaling out of the VNF instance. This abstraction is crucial for achieving the goals of NFV: hardware independence, efficient multi-tenancy, and agile service deployment.

Purpose & Motivation

The concept of the Virtualized Resource was introduced to address the limitations of traditional telecom networks built on proprietary, physical appliances. These appliances were tightly coupled to specific hardware, leading to long procurement and deployment cycles, inefficient resource utilization (often over-provisioned for peak capacity), and high operational costs. The shift towards Network Functions Virtualization (NFV), championed by industry forums like ETSI ISG NFV and adopted by 3GPP, required a standardized way to model and manage the software-based resources that would replace physical network functions.

The creation of the VR abstraction in 3GPP specifications, notably from Rel-13 onwards, provided this standardized model. It solved the problem of heterogeneity in cloud infrastructure by defining a common set of resource types (compute, storage, network) and their management interfaces, regardless of the underlying hypervisor (VMware, KVM, etc.) or hardware vendor. This allows network operators to deploy VNFs from different vendors on a common, shared pool of physical resources, enabling true multi-vendor interoperability and preventing vendor lock-in at the infrastructure layer. The VR model is the foundation for automation, elastic scaling, and the efficient "cloudification" of mobile networks, which are essential for supporting diverse 5G and beyond services with varying demands.