# On MPLS Forwarding Performance Myths

DevFeed: [On MPLS Forwarding Performance Myths](<https://devfeed.tech/articles/on-mpls-forwarding-performance-myths-11329.md>)

Original publisher: [Read original article](<https://blog.ipspace.net/2026/02/mpls-forwarding-performance/>)

Published: 2026-02-05T07:20:00Z

Content type: opinion

Language: en

Sources: [ipSpace.net blog](<https://devfeed.tech/sources/ipspace-net-blog.md>)

Topics: [networking](<https://devfeed.tech/topics/networking.md>), [Ethernet](<https://devfeed.tech/topics/ethernet.md>), [Cisco](<https://devfeed.tech/topics/cisco.md>), [Hardware](<https://devfeed.tech/topics/hardware.md>)

Tags: [cisco](<https://devfeed.tech/tags/cisco.md>), [devices](<https://devfeed.tech/tags/devices.md>), [hardware](<https://devfeed.tech/tags/hardware.md>), [ietf](<https://devfeed.tech/tags/ietf.md>), [ip](<https://devfeed.tech/tags/ip.md>), [mpls](<https://devfeed.tech/tags/mpls.md>), [performance](<https://devfeed.tech/tags/performance.md>), [switching](<https://devfeed.tech/tags/switching.md>)

## AI overview

The article examines claims about the original motivation for MPLS, arguing that aggregate forwarding performance in core devices mattered more than accelerating individual IP table lookups. It describes how mid-1990s service providers combined routers at the network edge with ATM switches in the core because routers lacked sufficient aggregate bandwidth.

## Source excerpt

Whenever I claim that the initial use case for MPLS was improved forwarding performance (using the RFC that matches the IETF MPLS BoF slides as supporting evidence), someone inevitably comes up with a source claiming something along these lines: The idea of speeding up the lookup operation on an IP datagram turned out to have little practical impact. That might be true1, although I do remember how hard it was for Cisco to build the first IP forwarding hardware in the AGS+ CBUS controller. Switching labels would be much faster (or at least cheaper), but the time it takes to do a forwarding table lookup was never the main consideration. It was all about the aggregate forwarding performance of core devices. Anyhow, Duty Calls. It's time for another archeology dig. Unfortunately, most of the primary sources irrecoverably went to /dev/null, and personal memories are never reliable; comments are most welcome. Read more ...