Initiate Disjoint LSPs                    
                 |                                       
                 |                       PCReq/PCRpt
                 V                        {DAG Y}      
              +-----+                ----------------> +-----+
   _ _ _ _ _ _| PCE |               |                  | PCE |
  |           +-----+               |      ----------> +-----+
  | PCInitiate                      |     |    PCReq/PCRpt
  |{DAG X}                          |     | {DAG Y}
  |                                 |     |
  |              .-----.            |     |         .-----.
  |             (       )           | +-----+      (       )
  |         .--(         )--.       | |PCC 2|--.--(         )--.
  V        (                 )      | +-----+ (                 )
+---+     (                  )      |        (                  )
|PCC|----(   (G)MPLS network )   +-----+    ( (G)MPLS network   )
+---+    (                   )   |PCC 1|-----(                  )
{DAG X}   (                 )    +-----+      (                )
           '--(         )--'                   (           )--'
               (       )                         (        )
                '-----'                            '-----'

Case 1: Disjointness initiated by   Case 2: Disjointness initiated by
    PCE and enforced by PCC              PCC and enforced by PCE