Understanding MPLS Label Stacking

jdoyle — Mon, 28 Jan 2008 22:25:04 -0500

In the last two posts I discussed the role of FECs in MPLS networks, and implicit and explicit null labels. In this brief post I’d like to discuss MPLS label stacking, as a preliminary to a couple of posts on MPLS VPNs.

Label stacking is the encapsulation of an MPLS packet inside another MPLS packet – that is, adding an MPLS header “on top of” (hence stacking) an existing MPLS header. The result of stacking is the ability to tunnel one MPLS LSP inside another LSP.

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