MPLS FAQ – For Beginners
April 3rd, 2010
Here is a basic overview of MPLS describing:
- What is Multi?Protocol Label Switching (MPLS)?
- What is a label? What is the structure of the label?
- Where will the label be imposed in a packet?
- What is a Forwarding Equivalence Class (FEC)?
- What is an upstream label switch router (LSR)?
- What is a downstream LSR?
- What do the terms incoming, outgoing, local, and remote mean when referring to labels?
- Can an LSR transmit/receive a native packet (non?MPLS) on a MPLS interface?
- Can an LSR receive/transmit a labeled packet on a non MPLS interface?
- What platforms and Cisco IOSs® support MPLS?
- Generic Routing Encapsulation (GRE) tunnel has a overhead of 24 bytes. How much overhead does an MPLS LSP tunnel have?
- How does the LSR know which is the top label, bottom label, and a middle label?
- What is the range of label values? What label values are reserved andWhat do the reserved values signify?
MPLS FAQ For Beginners (.pdf)