Transcript IPO-4

Considerations on the Development
of an Optical Control Plane
draft-freeland-octrl-cons-00.txt
Darren Freeland, Neil Harrison, Sergio Inglima,
Keith James, Alan McGuire, Shehzad Mirza, Stewart
Ritchie, Mel Robinson, Ali Salman, Peter Willis
Overview
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ID considers OTN control plane requirements
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Protocol Independent approach
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In response to exploder discussions
Current IETF approach
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Extending IP control protocols to the OTN control plane.
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May be the right answer, but has not been proven.
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Based on assumption that “IP traffic volumes will dominate the OTN”
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Is this argument valid though? …...
Darren Freeland et al
Considerations on the Development of an Optical Control Plane
IETF49 San Diego - 15th December 2000
1
Nature of the OTN User-Plane
OTN User Plane:
IP User Plane:
- Connection Oriented (CO)
- Connectionless (CNLS)
- Circuit Switched
- Packet Switched
- No buffering
- Buffering
- Transparent to Clients
- IP traffic only
- Control & User planes separable
- Control & User planes congruent
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User Plane & Control Plane traffic need not be congruently routed in the OTN.
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User Plane can accommodate large BW + new emerging client layers.
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User Plane is agnostic regarding type of traffic it carries (ATM, IP, GbE, etc).
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Is it valid to assume that control protocols
developed for a CNLS environment are suitable for the CO OTN?
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IP control plane should be analysed against OTN requirements.
Darren Freeland et al
Considerations on the Development of an Optical Control Plane
IETF49 San Diego - 15th December 2000
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Some Carrier Issues
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Large proportion of carriers require a multi-client OTN
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Different types of client layer networks may have different control planes
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Clients may use different naming/addressing schemes
De-coupling client & OTN layer control planes therefore ...
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ensures true multi-client OTN
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ensures that support for future client layers is not hampered by legacy technology
Clients will generally not be given full visibility of the OTN
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Topology/resource invisible to users at higher layers
Concern over type of info conveyed between carriers
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Inter-working will generally be restricted to requests for service
Darren Freeland et al
Considerations on the Development of an Optical Control Plane
IETF49 San Diego - 15th December 2000
3
Control Plane facets
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Naming & Addressing
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Signalling Network
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Interfaces
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Signalling Protocol
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Topology/Resource Discovery
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Routing Process
Darren Freeland et al
Considerations on the Development of an Optical Control Plane
IETF49 San Diego - 15th December 2000
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A few considerations
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OTN control plane will receive set-up requests for 10’s of thousands of
connections per day (per domain)
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Control Plane network must be at least as reliable as User Plane network
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Addressing scheme must be scalable enough to cope with future demands
Signalling failures should not affect existing user plane connections
Connection Admission Control (CAC) required at signalling interfaces
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e.g. user authentication & permissibility, verification of service level parameters, billing
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should provide a secure interface between the OTN and it’s various clients
OTN will consist of elements growing to the order of 1000+ ports
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implies much larger # of links between neighbours (in contrast to higher layers)
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routing processes must be able to scale in order to support them
Darren Freeland et al
Considerations on the Development of an Optical Control Plane
IETF49 San Diego - 15th December 2000
5
Interfaces
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Generally 2 types of control interface ... O-UNI & O-NNI
IP/MPLS client
FR/ATM client
Other client
O-UNI
O-UNI
O-UNI
i-ONNI
OTN 2
e-ONNI
other
UNI
O-UNI
IP/MPLS
UNI
FR/ATM
UNI
Access D1
OTN 1
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UNI may use in-band or out-band signalling
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NNI should use out-band signalling
Darren Freeland et al
Considerations on the Development of an Optical Control Plane
IETF49 San Diego - 15th December 2000
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Topology / Resource Discovery
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OTN will consist of a number of administrative domains
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owned by different carriers
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requires distinction between NNI’s within and between domains
IP/MPLS client
FR/ATM client
Other client
O-UNI
O-UNI
O-UNI
other
UNI
OTN 2
e-ONNI
i-ONNI
OTN 1
O-UNI
 Topology/Resource discovery
may be supported at i-ONNI
 Topology/Resource discovery
will not be supported at e-ONNI
 Topology/Resource discovery
will not be supported at OUNI
Darren Freeland et al
Considerations on the Development of an Optical Control Plane
IETF49 San Diego - 15th December 2000
IP/MPLS
UNI
FR/ATM
UNI
Access D1
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Proposals
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A number of carrier requirements are considered in
draft-freeland-octrl-cons-00.txt
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We propose that the list of conclusions from above draft be
considered as a contribution towards the ‘IPO Framework’ ID.
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Would also like to see an analysis of all control plane facets
against carrier requirements for the OTN.
Darren Freeland et al
Considerations on the Development of an Optical Control Plane
IETF49 San Diego - 15th December 2000
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