This specification describes the NSIS Signaling Layer Protocol (NSLP) for signaling Quality of Service (QoS) reservations in the Internet. It is in accordance with the framework and requirements developed in NSIS. Together with General Internet Signaling Transport (GIST), it provides functionality similar to RSVP and extends it. The QoS NSLP is independent of the underlying QoS specification or architecture and provides support for different reservation models. It is simplified by the elimination of support for multicast flows. This specification explains the overall protocol approach, describes the design decisions made, and provides examples. It specifies object, message formats, and processing rules.