Jul 02, 2015
SDN, NFV, and the Hype Cycle
Disclaimer
These are my own personal opinions, not Official Party Line(tm).
“A short (<1000 words) response to one (or more) of the following questions”
- What is SDN?- Why are you excited about SDN?- How does the network of the future differ from today’s?”
What is SDN?
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OpenFlow ‘Shimmer’ProgrammableNetworks
Scope creep, hype creep
SDN
• Match IP src/dest addr and src/dest ports
• Rewrite some packet bits (e.g., DSCP)
• Set QoS policy
• Set outgoing interface
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• OpenFlowroute-map foo
match ip address <acl>
set ip precedence <number>
set interface <name>
SDN
So what’s new?SDN (OpenFlow) is performant, high-scale, standardized policy routing
That’s pretty cool, and I’m sure I can do some cool stuff with it.
Is it Sliced Bread v2.0? No.
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• OpenFlow
SDN
“SDN for Video”: Level(3) has had this for 15 years
“Transport SDN”: Open APIs to transport gear
“Software Defined Data Center”: ???
“Software Defined Application Services”: ???
“Software Defined Enterprise WAN”: ?? ?? ??
Includes NFV, which it shouldn’t
“no one really knows what SDN is”
- Bob Metcalfe
Feels like the early days of MPLS
(which changed the world once we figured out what it was for)
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• ‘Shimmer’
SDN
• What does this mean? What does it enable? How does it work? What’s new and different about it?
i) Breaking things down into pieces
ii) Commoditizing those pieces
iii) Using those pieces to rebuild and to build new
8
• Programmable Networks
SDN
• Separate the control plane from the forwarding plane
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• Breaking things down into pieces
9
SDN
• RP-> Controller
• IPC -> OpenFlow/Netconf/I2RS/etc
• Router -> Linecard
10
• Breaking things down into pieces
This is interesting.
Makes for all sorts of interesting combinations
RP
Cisco
Juniper
Open$FOO
$BAR
$BAZ
LC
Cisco
Juniper
Open$FOO
$BAR
$BAZ
Why are you excited about SDN?
• I’m not.
Why are you excited about SDN?
• I’m not.
• What I *am* excited about is NFV.
How does the network of the future differ from today’s?• Network as programmable fabric
• This isn’t about SDN. It’s about customer-facing APIs
• Tricky part: what do we actually want to offer?
• NFV is a big (the biggest?) part of this
• Virtualizing the heretofore un-virtualizable• Some value in separating hardware and software
• Need to be careful, this isn’t a Hadoop cluster - a CPE is a single point of failure
• Downside of mix and match is that I’m the one responsible for it
• Some value in moving CPE functions to a data center• Economies of scale
• Easy relocation on failure
What do we need to get there?
• Is the network now a data center, or is the data center now a network?
• Just because you’re good at one doesn’t mean you’re good at both• c.f. DC virtualization – fixed bit space, Ethernet as the One True Protocol
What do we need to get there?
• NEED:• Smooth handoff between host and network (MPLS?)
• Tools that do the hard parts ...and do them in a sensible, extensible, componentized, cross-vendor way.
• Enough knobs and levers that we can still build competing products• How do we compete if everyone runs the same VNFs, orchestrator, service chain and
abstraction layer?