RSVP Basic features Simplex reservation one way reservation
RSVP • Basic features: – Simplex reservation: one way reservation – Receiver oriented: receivers decide what resources to reserved and initiates the reservation – Routing independent – Policy independent: e. g independent of admission control – Soft state: dealing with the changing of group members – Various reservation styles
• Operation overview – PATH messages and RESV messages (Figure 2. 6) • PATH messages (downstream) – Distribute traffic source information – Collect path information – Install necessary state • RESV messages (upstream) – Follow the reserved path of PATH messages – Specify the resource requirements – Setup state in the path
• RSVP messages • Sent between hops as raw IP datagrams (prototype Id 46) • Can be encapsulated in UDP packets (used in end systems) • These packets need special treatment: Use Router Alert • Refresh periodically – PATH message: • • Previous Hop Sender Template TSpec Adspec (optional, OPWA) collect path information.
• RSVP messages – RESV messages • Reservation style • Flow spec and filter Spec (Flow descriptor) – Flow spec: Desired Qo. S and parameters for packet scheduling depending on the service requested » Service Class » RSpec » TSpec – Filter Spec (sender template) + session specification defines the flow
• RSVP messages – Message format: common header (Figure 2. 7) + RSVP objects (Figure 2. 8) – Reservation Styles: • Wild-card-filter (WF) style: WF(*, {Q}) • Fixed-filter (FF) style: FF(S 1(Q 1), S 2(Q 2), …, Sn(Qn)) • Shared explicit (SE) style: SE((s 1, s 2, …, sn){Qn}) • Example: Figure 2. 10 -2. 12
• Adspec – Pass the path information for the destination – Three components: a default general parameters fragment, a guaranteed service fragment, and a controlled load service freament – Default general parameters: • • • Minimum latency Path bandwidth Int. Serv hop count Global break bit Path MTU
• Adspec – Guaranteed service fragment • Ctot, Dtot, Csum, Dsum – Controlled load service fragment: • Controlled load service break bit and options • How to compute RSpec for guaranteed service? – Required bandwidth – Slack Term • RFC 2205, 2208, 2209, 2210
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