Inter-Area TE LSP (ERO Expansion Method)

Inter-area contiguous LSP scheme provides end-to-end TE path. Each transit node in an area can set up a TE path LSP based on TE information available within its local area.

A PE node initiating an inter-area contiguous TE LSP does partial CSPF calculation to include its local area border router as a loose node.

Area border router on receiving a PATH message with loose hop ERO does a partial CSPF calculation to the next domain border router as loose hop or CSPF to reach the final destination.