QoS - RSVP bandwidth and flow reservations
When implementing RSVP as a QoS mechanism, we use the ip rsvp bandwidth command on participating routers to reserve resources along the communication path.
In its most basic form, this command specifies two values:
- The maximum amount of bandwidth, in kb/s, that can be allocated by RSVP flows. The range is from 1 to 10000000.
- The maximum amount of bandwidth, in kb/s, that may be allocated to a single flow. The range is from 1 to 10000000.
An example of the command on a particular interface is as follows:
Router(config-if)#ip rsvp bandwidth 256 64
This command reserves a total of 256 kb/s for all RSVP flows, and reserves a maximum of 64 kb/s for each individual flow.
Thus, this interface can support RSVP flows of up to 64 kb/s each, and can support a total flow bandwidth of 256 kb/s.
That means that the interface can support four flows of 64 kb/s each, or eight flows of 32 kb/s each or a combination of two flows of 64 kb/s each and four flows of 32 kb/s each, and so on. As long as the total bandwidth of all the flows does not surpass 256 kb/s.
Any attempts at creating individual flows larger than 64 kb/s or creating a number of flows that will surpass a total of 256 kb/s will fail.
Links:
https://forum.networklessons.com/t/introduction-to-rsvp/1008/47?u=lagapides
https://networklessons.com/quality-of-service/introduction-to-rsvp
https://www.cisco.com/c/en/us/td/docs/ios/qos/command/reference/qos_book/qos_i1.html#wp1051778