att_abstract={{Network Functions Virtualization (NFV) was recently proposed to improve the flexibility of network service provisioning and reduce the time to market of new services. By leveraging commercial-off-the-shelf programmable hardware, such as general purpose servers, storage and switches, NFV decouples the software implementation of network functions from the underlying hardware. It also consolidates various network equipment types in different locations, including customers’ premises, network points of presence and data centers. As an emerging technology, NFV brings several challenges to network operators, such as the guarantee of network performance for virtual appliances, their dynamic instantiation and migration, and their efficient placement. In this article, we provide a brief overview of NFV, explain its requirements and architectural framework, present several use cases and discuss the challenges and future directions in this burgeoning research area.}},
	att_authors={bh1729, vg7777, sl1858, lj1412},
	att_copyright_notice={{This version of the work is reprinted here with permission of IEEE for your personal use. Not for redistribution. The definitive version was published in 2014. {{, 2015-02-01}}
	att_tags={Network Functions Virtualization,  Virtual Network Appliance,  Cloud RAN,  Cloud EPC},
	author={Bo Han and Vijay Gopalakrishnan and Seungjoon Lee and Lusheng Ji},
	institution={{IEEE Communications Magazine}},
	title={{Network Functions Virtualization: Challenges and Opportunities for Innovations}},