Shared Explicit (SE) Style

Shared Explicit (SE) Style

Shared Explicit style reservations are characterized by a shared reservation and an explicit sender, creating a reservation that is shared by specific senders. The SE style is represented by

SE((S1,S2,...Sn){Q})

indicating that the list of senders shares the reservation Q. SE style type reservations are illustrated in Figure 10-6 with the bandwidth allocations listed in Table 10-4.

Figure 10-6: Shared Explicit SE(S{Q}) reservation style example

Table 10-4: Bandwidth Allocations for the Shared-Explicit (SE) Style Example

Router

Interface E0

Interface E1

Interface S0

Interface S1

Interface S2

A

300K

300K

300K

100K

B

100K

100K

C

300K

300K

D

200K

200K

E

300K

300K

F

300K

300K

When router A in Figure 10-6 receives the requests

SE(S1{{200K}) + SE((S1,S3){300K})

from routers C and D, the filter specs are combined and the flow spec is set to the largest flow spec received. The resulting flow descriptor will be ((S1,S2,S3){300K}).

Reservation Style Summary

The three RSVP styles and the actions a router will take when merging requests are summarized in Figures 10-7 through 10-10.

Figure 10-7: The merging of WF style RSVP requests. The size of the resource allocated is equal to the largest, regardless of the senders.

Figure 10-8: The merging of FF style RSVP requests for distinct sources is shown. For each distinct source allocated, the requested resource is shown also. For a common source allocated, the largest of the resource is requested. The allocated bandwidth equals 300.

Figure 10-9: The merging of FF style RSVP requests for a common source. For a common source, allocate the largest of the resources requested. The allocated bandwidth equals 100.

Figure 10-10: The merging of SE style RSVP requests. Merge all sources and allocate the largest of the requested resource for all specified sources. The total bandwidth allocated equals 300.