Multiprotocol Label Switching (MPLS)

Teahnique that is leveraged by service providers to elevate the efficency and flexibily of their networks.

opperates behindd the scenes and streamlines and speeds up the data flow.

introduces label switching - just fowrard data buy path info.

1 label assignment short fixed legenth ID.

2 label switching - router looks at the label and then determines the packets next hop. faster than route look up.

3 label removal - label is removed then it is back to normal TCP/IP routing.

Versatility - can carry any type of protocol. used by ISP and back haul.

Great for QoS can enforce traffic engineering.

Reliability

Redundancy

Used by servide providers for forwarding data in the back end. improved performance and service on modern networks. Above tradational IP routing.

MPLS = Label Routing

MPLS (Multiprotocol Label Switching)

Purpose

Service provider technique to improve efficiency, flexibility, and speed of data forwarding.
Works behind the scenes → faster than traditional IP routing.
Common in ISP backbones and enterprise WANs.

How MPLS Works

Label Assignment
- Packets entering an MPLS network are given a short, fixed-length label.
Label Switching
- Routers (Label Switch Routers, LSRs) forward packets based on labels, not full IP lookups.
- Much faster than traditional routing.
Label Removal (Penultimate Hop Popping)
- Before the packet exits the MPLS domain, the label is stripped.
- Normal IP routing resumes.

Key Features

Protocol-Agnostic → can carry IPV4, IPV6, Ethernet, ATM, Frame Relay, etc.
Performance → faster forwarding than IP routing.
Quality of Service (QoS) → supports traffic engineering (prioritize voice/video).
Reliability & Redundancy → enables robust service provider backhaul.

✅ Exam Must-Knows

MPLS = Label-based forwarding, not IP header lookup.
Improves QoS (great for VoIP, streaming).
Used mainly by ISPs & large enterprise WANs.
Steps: Label assignment → Label switching → Label removal.

⚡Memory Trick:

MPLS = "Maps Packets with Little Stickers" → Labels act like stickers that tell routers where to send the packet, no need to read the whole address.