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Requirements for the
Resilience of Control Plane in
GMPLS
(draft-kim-ccamp-cpr-reqts-00.txt)
CCAMP WG (59th IETF)
Apr.04, 2004
Young Hwa Kim
([email protected])
Contents
1. Summary of the draft
2. Necessities for Resilience of Control Networks
3. Conclusion
59th IETF(CCAMP WG) (2/9)
1. Summary of the draft (2/1)
▣ 3 components of CP : entities, nodes, and channels
▣ Control networks
 Control modes
 Network configurations
▣ Some concepts for the resilience of control networks
 Control packet type
 Active and standby control channels
 Protection group …
▣ Requirements for the resilience of control networks
 Configuration of control networks
 Priorities in control channels
 Reverting and non-reverting modes of control
channels
59th IETF(CCAMP WG) (3/9)
1. Summary of the draft (2/2)
▣ Necessities for the resilience of control networks
▣ Relation to LMP
▣ Possible functions for the resilience of control
networks
 Identification of an active control channel
 Negotiation of switchover attributes
 Verification of standby control channels
 Automatic switchover
 Forced switchover
 Inquiry of switchover attributes
 Notification of protocol errors
 Parameter negotiation and Hello protocol
59th IETF(CCAMP WG) (4/9)
2. Necessities for Resilience of Control Plane (1/3)
▣ Current status of control plane
 Weak concept of control network
 Slow convergence of IP routing protocols due to
hello intervals and expiration timer values
 Alternative diverse paths between communication
entities
 A control network to experience an independent
failure from the transport network, and its impact
on connection setup and teardown requests
 Also, control channels to share common physical
routes with the transport network, and its impact
on restoration of existing connections
 Separation of control channels in GMPLS
 Control channel management in LMP
59th IETF(CCAMP WG) (5/9)
2. Necessities for Resilience of Control Plane (2/3)
▣ Control channel management in LMP
 Control channel activation with parameter
negotiation
 Hello protocol
 Control channels independent of TE links
 Possible multiple active control channels between
a pair of nodes
 If a failure on an active control channel occurs,
alternative active control channels can be used, or
the activation procedure can be performed.
 No guarantee of the same level of service about TE
links in a Degraded state
59th IETF(CCAMP WG) (6/9)
2. Necessities for Resilience of Control Plane (3/3)
▣ Is the status satisfactory? No. Then, why?
 Few consideration of control modes and several
control network configurations
 While admitting the resilience of transport plane, no
care of the resilience of control plane
 No resilience concept in LMP
 If there is no active control channel under the situation
that a control channel is responsible for several TE
links, the links fall into the Degraded state. We do not
want it.
 Even when there is a failure of an active control
channel on restoration of existing connections, we do
not want to start the control channel activation again,
and we should be capable of identifying an alternative
active control channel promptly.
59th IETF(CCAMP WG) (7/9)
3. Conclusion
▣ The draft introduced a framework for the resilience of
control plane.
▣ The control channel management in LMP is not
sufficient for the resilience of control plane in GMPLS.
▣ The resilience of transport plane may be included the
current charter of the CCAMP WG, but whether the
one of control plane is included in the WG or not …
▣ If agreed to this point, let’s put the resilience of
control plane into a basket of re-chartering items.
▣ Then, I propose this draft as a WG document of the
CCAMP WG.
▣ Future works
 Refinement of this draft; and
 Proposal of a preliminary protocol specification.
59th IETF(CCAMP WG) (8/9)
Thank you.
Young Hwa Kim
([email protected])