What is the total length of an MPLS label stack entry (MPLS header)?

An MPLS label stack entry, often referred to as an MPLS header, is 32 bits long. This 32-bit structure consists of four fields: the 20-bit Label field, the 3-bit Experimental (EXP) field (now commonly used for QoS CoS), the 1-bit Bottom of Stack (S) field, and the 8-bit Time to Live (TTL) field. This fixed length allows for efficient processing by Label Switch Routers (LSRs). 16 bits is incorrect as it's too short to accommodate all necessary fields. 20 bits is incorrect because it only accounts for the Label field itself, not the entire stack entry. 28 bits is incorrect as it does not include the full 32 bits required for the complete MPLS header.