label switching (networking) A routing technique that uses information from existing IP routing protocols to identify IP datagrams with labels and forwards them to a modified switch or router, which then uses the labels to switch the datagrams through the network.
Label switching combines the best attributes of data link layer (layer two) switching (as in ATM and Frame Relay) with the best attributes of network layer (layer three) routing (as in IP). Prior to the formation of the MPLS Working Group in 1997, a number of vendors had announced and/or implemented proprietary label switching. Last updated: 2007-10-17