Dynamic Adaptation of VNF Forwarding Graph

proposed NFVRG, July 2014

S. Lee, M.-K. Shin (ETRI){seungiklee, mkshin}@etri.re.kr

E. Paik (KT)eun.paik@kt.com

Background

• VNF forwarding graph (or SFC): – a logical connectivity b/w virtual appliance

(VNFs)

• Network forwarding path (or SFP): – an instance of VNFFG

Update of VNFFG

• Change of VNF in VNFFG; change of VNF instance in NFP

• in MANO– update of network service descriptor

• in Use cases– VNF instance relocation for service continuity, service availabil-

ity in mobile core network– provisioning, restoration, localization of failure, resizing of VN-

FFG– modification of resource assignment at load changes and fail-

ure

• motivates automated and dynamic update of VNFFG considering NFV resources

Dynamic Adaptation of VNFFG

• “Creation and dynamic update of VNFFG and NFP adaptively to status of resources/traffic” (not scale-up/down)

① Failure of SF instance

③ VNF instance

replacement

② Detection of failure

VNF-A #1 VNF-B #1

VNF-B #2

Dynamic Adaptation of VNFFG

• Examples– Traffic optimization: construct NFPs with low stress

and stretch considering the different locations of multiple SF instances.

– Fail-over: select live VNF instances and replaces VNF instances in failure by checking their availability

– Load balancing: select VNF instances to distribute load for the traffic considering the current status of VNF instances or nodes where the instances are embedded

– Security threat: add or remove VNFs at a doubtful state of resource and traffic

Dynamic Adaptation of VNFFG

• Target actions– selection/replacement of {VNF, VNF instances}

• Target resources– VNF, VNF instances, nodes, links, traffic

• Metrics (what to consider)– Availability, load, performance of VNF instances,

nodes, links (among VNF instances)– Topological location of source, destination, VNF

instances, nodes– Volume of traffic flow– ...

Further Steps

• More use cases & metrics• Algorithms & approaches to adaptation• Required common functionalities

– e.g., metric calculation, monitoring, status query/report, topology extraction, ...

• Other issues– redundant NFPs with state synchronization for

resiliency– programmability of VNFFG/NFP adaptation

• As a control-plane mechanism in SFC WG