A customer is discussing QoS requirements with a network consultant. The customer has specified that endto-end path verification is a requirement. Which QoS solution meets this requirement?

The Integrated Services (IntServ) model with Resource Reservation Protocol (RSVP) provides end-to-end path verification by reserving resources along the entire data path. RSVP ensures that the necessary bandwidth and delay guarantees are available from source to destination for specific traffic flows, making it suitable for applications requiring strict QoS guarantees.

The Differentiated Services (DiffServ) model with Per-Hop Behavior (PHB) focuses on classification and marking at each hop, providing local QoS treatment rather than end-to-end path verification or strict resource reservation.

Marking traffic at the access layer with DSCP is a component of the DiffServ model, which provides localized QoS treatment but does not inherently offer end-to-end path verification or resource reservation.

Marking traffic at the access layer with CoS (Class of Service) is a Layer 2 marking mechanism, similar to DSCP, used in the DiffServ model and also does not provide end-to-end path verification or resource reservation.