Post on 21-Dec-2015
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