Bridging Network Management and Software- Defined Networking

Transcription

1 Bridging Network Management and Software- Defined Networking Panel NOMS 2014 Alexander Clemm, 5/8/ Cisco and/or its affiliates. All rights reserved. 1

2 Early days: SDN very clearly separated Subject of control: FIBs (and RIBs) vs MIBs Real-time nature: Control vs Management Programmability: Focus on interfaces that used to be closed More recent developments Narrow scope, limited use cases à generalization and wider application Replace & commoditize à complement & add value to network functions Control à management automation Networking à management technology Compare early-days Openflow with today s Open Daylight 2010 Cisco and/or its affiliates. All rights reserved. 2

3 2010 Cisco and/or its affiliates. All rights reserved. 3

4 Mgmt UI Base mgmt services Model-driven architecture, tool chains Support for multiple protocols incl. SNMP Multiple (increasingly heterogeneous) devices 2010 Cisco and/or its affiliates. All rights reserved. 4

5 Heterogeneity >> Scale >> Algorithms Management s biggest challenge: variations in devices, capabilities, interfaces Mediation and adaptation at scale is difficult Management support can be bottleneck for deployment Integration investment as barrier to adoption Can t roll out devices & features unless supported by OSS Reluctance to invest in feature support unless proven demand Simplicity of server/agent instrumentation is key to adoption Simplicity (ease of instrumentation) beats ease of use Complexity is pushed up, even at the loss of efficiencies (example, SNMP) Separate Information/Data Models from transport/services Effort: Instrumentation: 90% & recurring, services/transport: 10% & once Consistency across interfaces Policies, promise theory are effective at addressing heterogeneity, scale 2010 Cisco and/or its affiliates. All rights reserved. 5

6 Delegating, distributing some management functionality makes sense Time scales, efficiency but redundant configuration doesn t Need for redundant configuration easily results in inconsistencies Large portion of downtimes due to misconfiguration TMN reference model & separation of concerns Abstraction layers: NE à EM à NM à SM à BM Functional partitioning: FCAPS; Specific Management Functions but layering applied naively creates problems Multi-layered cakes, redundant data and data models at each layer, slow TTM Excessive mediation impedes incentive for good interfaces Management as an afterthought by design 2010 Cisco and/or its affiliates. All rights reserved. 6

7 Single integrated platforms Generic platforms & jacks-of-all trades à ecosystems of specialized components / applications & masters-of-one Global all-encompassing information models Governance, learning curve, TTM Overreliance on polling Call home, reverse management patterns Event-Driven Management, Netflow Generic one-size-fits-all protocols SNMPà SNMP/Netflow/CLI/Netconf/DHCP/syslog/REST/ Need to support the right tool for the task, one hammer does not fit all nails 2010 Cisco and/or its affiliates. All rights reserved. 7

8 Data/information models: separate data/instrumentation and transport/services Accommodate possibility of multiple transports and message exchange patterns Avoid data mediation: network abstractions to complement, not hide device abstractions Lower meets upper Agent renders policy, avoid reliance on mediation by controllers Applications that complement and leverage (vs just reimplement) network value Business case, provide incentive for agents Allow smart choices where to put intelligence in controller or at the edge Allow for multiple controllers but avoid conflicting masters Avoid issues of resynchronization that make management hard Single point of ownership and administrative control for SDN functions Clear focus, narrow and well-contained use cases Avoid over-extension, rapid over-generalization Simple, confined interface functionality to ease implementation, proliferation 2010 Cisco and/or its affiliates. All rights reserved. 8

9 Single point of administration by design Easier to manage: greater consistency, better efficiency, less error-prone Forcing point to achieve interface alignment Lower meets upper; greater virtualization of device interfaces & functions Controlled system needs to meet controller interface, not other way round Allow management to focus on applications & algorithms instead of mediation Management not as afterthought but key to unleashing network value From Network functions independently of its need to be managed To Network does not function without management/control Network management applications and functions are hot again Mindshare is good 2010 Cisco and/or its affiliates. All rights reserved. 9

10 Of course not Network management is not a technology for its own sake, but driven by need to operate, administer, maintain, provision networks & services Still need to report, to monitor, to troubleshoot, to protect, Nature of management may be affected Control and management planes converge Management automation à SDN Nothing new, either, compare: Static route provisioning à routing protocols IP address management à DHCP SDN enables greater manageability, bring NM to a higher level From focus on mediation & dealing with heterogeneity to focus on mgmt algorithms From SDN to SDM: Software Defined Manageability 2010 Cisco and/or its affiliates. All rights reserved. 10

11 It depends on expectations Hype: Single controller solves all management problems Programming and extending network functionality will be super simple Decentralized and embedded intelligence inside network is obsolete Networks will become completely commoditized and dirt cheap Inconsistencies will be a thing of the past Getting there is easy Not hype: Programmable network, extensibility of network functionality Virtualization of interfaces, networking functions Operational considerations, simplification as major networking factor Network no longer considered independent of need to be managed 2010 Cisco and/or its affiliates. All rights reserved. 11

12 The key is not commoditization of the network, but adding value The opportunity of SDN is not simply about sucking intelligence into controllers The opportunity is to make networks easy to program, extend, operate while leveraging and complementing network-embedded value/intelligence where it makes sense Some of this functionality involves control loops that automate & shorten time scales of management tasks SDN does not replace management but helps bring it to a higher level SDM Software Defined Manageability Cisco and/or its affiliates. All rights reserved. 12

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