Question

Which field in the MPLS header identifies the stack button

Answer 1

Answer:

Each entry in the label stack contains four fields:

A 20-bit label value. A label with the value of 1 represents the router alert label.

a 3-bit Traffic Class field for QoS (quality of service) priority and ECN (Explicit Congestion Notification). Prior to 2009 this field was called EXP.[8]

a 1-bit bottom of stack flag. If this is set, it signifies that the current label is the last in the stack.

an 8-bit TTL (time to live) field.