Data Flows - Session Data flow identified by destination Resources allocated by router for duration of session Defined by – Destination IP address Unicast or multicast – IP protocol identifier TCP, UDP etc. – Destination port May not be used in multicast

Flow Descriptor Reservation Request – Flow spec Desired QoS Used to set parameters in node’s packet scheduler Service class, Rspec (reserve), Tspec (traffic) – Filter spec Set of packets for this reservation Source address, source prot

Treatment of Packets of One Session at One Router

RSVP Operation Diagram

RSVP Operation G1, G2, G3 members of multicast group S1, S2 sources transmitting to that group Heavy black line is routing tree for S1, heavy grey line for S2 Arrowed lines are packet transmission from S1 (black) and S2 (grey) All four routers need to know reservation s for each multicast address – Resource requests must propagate back through routing tree

Filtering G3 has reservation filter spec including S1 and S2 G1, G2 from S1 only R3 delivers from S2 to G3 but does not forward to R4 G1, G2 send RSVP request with filter excluding S2 G1, G2 only members of group reached through R4 – R4 doesn’t need to forward packets from this session – R4 merges filter spec requests and sends to R3 R3 no longer forwards this session’s packets to R4 – Handling of filtered packets not specified – Here they are dropped but could be best efforts delivery R3 needs to forward to G3 – Stores filter spec but doesn’t propagate it

Reservation Styles Determines manner in which resource requirements from members of group are aggregated Reservation attribute – Reservation shared among senders (shared) Characterizing entire flow received on multicast address – Allocated to each sender (distinct) Simultaneously capable of receiving data flow from each sender Sender selection – List of sources (explicit) – All sources, no filter spec (wild card)

Reservation Attributes and Styles Reservation Attribute – Distinct Sender selection explicit = Fixed filter (FF) Sender selection wild card = none – Shared Sender selection explicit= Shared-explicit (SE) Sender selection wild card = Wild card filter (WF)

Wild Card Filter Style Single resource reservation shared by all senders to this address If used by all receivers: shared pipe whose capacity is largest of resource requests from receivers downstream from any point on tree Independent of number of senders using it Propagated upstream to all senders WF(*{Q}) – * = wild card sender – Q = flowspec Audio teleconferencing with multiple sites

Fixed Filter Style Distinct reservation for each sender Explicit list of senders FF(S1{Q!}, S2{Q2},…) Video distribution

Shared Explicit Style Single reservation shared among specific list of senders SE(S1, S2, S3, …{Q}) Multicast applications with multiple data sources but unlikely to transmit simultaneously

Reservation Style Examples