2. Introduction

Resource reservation is a basic function for the operation of a virtualized telecom network. In resource reservation, VIM reserves resources for a certain period as requested by the NFVO. A resource reservation will have a start time which could be into the future. Therefore, the reserved resources shall be available for the NFVO requested purpose (e.g. for a VNF) at the start time for the duration asked by NFVO. Resources include all three resource types in an NFVI i.e. compute, storage and network.

Besides, NFVO requires abstracted NFVI resource capacity information in order to take decisions on VNF placement and other operations related to the virtual resources. VIM is required to inform the NFVO of NFVI resource state information for this purpose. Promise project aims at delivering the detailed requirements on these two features defined in ETSI NFV MAN GS [NFVMAN], the list of gaps in upstream projects, potential implementation architecture and plan, and the VIM northbound interface specification for resource reservation and capacity management.

2.1. Problem description

OpenStack, a prominent candidate for the VIM, cannot reserve resources for future use. OpenStack requires immediate instantiation of Virtual Machines (VMs) in order to occupy resources intended to be reserved. Blazar can reserve compute resources for future by keeping the VMs in shelved mode. However, such reserved resources can also be used for scaling out rather than new VM instantiation. Blazar does not support network and storage resource reservation yet.

Besides, OpenStack does not provide a northbound interface through which it can notify an upper layer management entity e.g. NFVO about capacity changes in its NFVI, periodically or in an event driven way. Capacity management is a feature defined in ETSI NFV MAN GS [NFVMAN] and is required in network operation.