Helllo,
The terms "unsolicited downstream distribution" (frame-mode MPLS) and "downstream on demand" (cell-mode MPLS) usually refer to two different modes of label distribution with LDP (or TDP) and not for RSVP. Unlike LDP, where both distribution modes exist and are implemented, for MPLS TE and RSVP there is no analogy to "unsolicited downstream".
If you want to use those terms for RSVP in MPLS TE I would say "downstream on demand" would suite best, because the labels for a MPLS TE tunnel are only distributed to those LSR, which transport traffic along the path of the tunnel. With unsolicited downstream distribution a LSR distributes labels to all of his neighbors - no matter whether they will ever be used or not.
From another point of view: RSVP with MPLS TE behaves similar to LDP in cell mode MPLS - both are used to signal a vc-like LSP.
Hope this helps! Please rate all posts.
Regards, Martin
