Which of the following modes are used by RSVP-TE on an Alcatel-Lucent 7750 SR?

RSVP-TE, as implemented on the Nokia 7750 SR and defined by IETF standards, uses a specific combination of label distribution and control modes. It employs "downstream-on-demand" label distribution, where a downstream router allocates and sends a label upstream only after receiving a request (a Path message) from an upstream router. It uses "ordered control," meaning a router will only send a label mapping upstream (in a Resv message) after it has received a label mapping from its own next-hop downstream neighbor for the same Forwarding Equivalence Class (FEC).

A. Independent control is not used by RSVP-TE. In independent control, a router can advertise a label without waiting for its downstream peer.
B. RSVP-TE uses neither independent control nor downstream unsolicited label distribution. Downstream unsolicited is characteristic of LDP, not RSVP-TE.
D. While RSVP-TE uses ordered control, it does not use downstream unsolicited label distribution. Labels are only provided upon request.

1. Nokia 7750 SR OS MPLS Guide, Release 21.10.R1, "RSVP-TE," Section: RSVP-TE Protocol Overview. The guide describes RSVP-TE's operation which aligns with ordered control and downstream-on-demand principles.

2. RFC 3209, "RSVP-TE: Extensions to RSVP for LSP Tunnels," Section 4.1. "LSP Tunnel Control." This RFC specifies that label allocation is downstream-on-demand and the signaling process (Path downstream, Resv upstream) inherently creates an ordered control plane for label distribution.