Hello ;
Ive a very complicated time with this concept "MPLS FEC" when i review the INE course called "MPLS fundamentals". He said when you talked about MPLS FEC "it is referring to the MPLS path thats supposed to be taked from site-1 to site-2 once they are labeled ".then He said "the technical term for the FEC is a group of paackets that are forwarded in the same manner without any priority for these packets and take the same path with the same treatment"and now supposed that in this diagram
if P5 has 3 equal cost paths in his LFIB and in his forwarding table to the dst 1.1.1.1/32 on CE-1 .
P5-P2 is the first path
P5-P3 second path
P5-P4 third path
when we first talk about MPLS FEC he said " it is used in order to take the EXACT SAME PATH EACH TIME TO REACH TO THE FINAL DST"which means if we have this scenario and P5 have more than one path to get to the final dst 1.1.1.1/32 and P5 wants to use his own MPLS FEC that means P5 MUST USE THE EXACT SAME PATH for each packet .that is the point i`m asking about. so, if P5 wants to use MPLS FEC P5 must use the same label EVEN THOUGH he has more than one label . P5 is going to choose the path via P2 so he is going to choose the label=200 and the labe=300 or label=400 are not going to be used at all. why you said P5 is going to do multipath? that breaks the rule of MPLS FEC.