{"draft":"draft-ietf-pce-hierarchy-fwk-05","doc_id":"RFC6805","title":"The Application of the Path Computation Element Architecture to the Determination of a Sequence of Domains in MPLS and GMPLS","authors":["D. King, Ed.","A. Farrel, Ed."],"format":["ASCII","HTML"],"page_count":"33","pub_status":"INFORMATIONAL","status":"INFORMATIONAL","source":"Path Computation Element","abstract":"Computing optimum routes for Label Switched Paths (LSPs) across multiple\r\ndomains in MPLS Traffic Engineering (MPLS-TE) and GMPLS networks presents a\r\nproblem because no single point of path computation is aware of all of the\r\nlinks and resources in each domain.  A solution may be achieved using the Path\r\nComputation Element (PCE) architecture.\r\n\r\nWhere the sequence of domains is known a priori, various techniques can be\r\nemployed to derive an optimum path.  If the domains are simply connected, or\r\nif the preferred points of interconnection are also known, the Per-Domain Path\r\nComputation technique can be used.  Where there are multiple connections\r\nbetween domains and there is no preference for the choice of points of\r\ninterconnection, the Backward-Recursive PCE-based Computation (BRPC) procedure can\r\nbe used to derive an optimal path.\r\n\r\nThis document examines techniques to establish the optimum path when\r\nthe sequence of domains is not known in advance.  The document\r\nshows how the PCE architecture can be extended to allow the optimum\r\nsequence of domains to be selected, and the optimum end-to-end path\r\nto be derived through the use of a hierarchical relationship between\r\ndomains.  This document is not an Internet Standards Track \r\nspecification; it is published for informational purposes.","pub_date":"November 2012","keywords":[],"obsoletes":[],"obsoleted_by":[],"updates":[],"updated_by":[],"see_also":[],"doi":"10.17487\/RFC6805","errata_url":null}