Uses RSVP to revers bandwidth
Service garantee is end-to-end
Can perform CAC
RSVP uses various mssage types to setup;
- PATH Message (from the initiator)
- RESV Messgage (back towards the sender)
- TEARDOWN Messgae (from either sender or reciever)
There are 3 types of QoS services offered by RSVP,
- Best-effort (FIFO, so not really QoS)
- Guranteed rate
- Controlled load (form of CAC)
RSVP works in both control plane and data plane. In the control plane the job of RSVP is CAC (permit or deny reservation request). In the data plane function give priority to traffic (WRED, WFQ) with scheduling and policing. RSVP has very high priority on the data plane.
router(config-if)# ip rsvp bandwidth [interface-kbps] [single flow kbps] #Enables RSVP
router(config-if)# ip rsvp resource-provider none #Disables Reserving Interface resources
router(config-if)# ip rsvp data-packet classification none #Disables Packet Classification
IntServ and DiffServ can intergrate together.