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Path Computation Element (PCE) Extensions for Link State Conflict Avoidance Mechanism in Optical Transport Networks

Document Type Expired Internet-Draft (individual)
Expired & archived
Authors Xuefeng Lin , Li Xin , Jie Zhang , Min Zhang , Hongxiang Wang
Last updated 2013-07-05 (Latest revision 2013-01-01)
RFC stream (None)
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Expired
Telechat date (None)
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


This document proposes a PCE based link state conflict avoidance mechanism. Path Computation Element (PCE) can compute a network path or route based on the information stored in Traffic Engineering Database (TED) and TED collects the link resources information through the OSPF-TE protocol. The proposed conflict avoidance mechanism gives each link two state which respectively represents the resource in this link is changed or not. The extended OSPF-TE protocol will also flood the link state information when it floods the link resources information. PCE will add the link state to the calculated path when it returns the calculated path to Path Computation Clients (PCC). When the RSVP-TE protocol reserves the resource along the calculated path, it will compare the link state stored in the calculated path with the link state stored in the local. If the link state between the calculated path and the local is inconsistent then the RSVP-TE protocol will stop the resource reservation process, release the reserved resource and promote the OSPF-TE protocol to flood the Link resources information immediately.


Xuefeng Lin
Li Xin
Jie Zhang
Min Zhang
Hongxiang Wang

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)