This object indicates the direction of data flow, such as forward or reverse, on this particular incoming GMPLS label switch path segment. An administrator sets this when manually configuring an in-segment as part of building or troubleshooting a GMPLS label-switched path, since direction determines how traffic through this segment is expected to flow relative to the overall LSP. With the default of forward, a newly created in-segment would assume traffic flows in the standard direction unless explicitly set otherwise.