Hello Siva,
in the output the values inside the TLV are expressed in bytes/s instead of bps, as a result of this everything is divided by 8.
Priority classes 0 to 3 are left untouched to 2500000 bytes / s = 20 Mbps .
The tunnel 7 having setup priority and hold priority 4 reduced the unrserved bandwidth for pool Pri 4 and all the lower values by a 12500 bytes/ s = 100 Kbps.
Tunnel 6 does the same but from traffic class priority 5 to 7 and with a stated bandwdith of 500 kbps = 62500 bytes /s of reduction.
The end result is that traffic classes 5 to 7 have an unused bandwidth of 2500000 -12500 -62500 = 2425000 bytes /sec.
Why a tunnel with priority 4 impacts on traffic classes 4 to 7: because a new tunnel with setup priority 4 to 7 cannot take its place over the link. This is the reason why the unused bandwidth is reduced in multiple classes the Constrained SPF must take in account that the resource is not available for those levels of priorities.
Your lab test clearly show this one tunnels impacts on traffic classes from 4 to 7 and the other one from 5 to 7 and this also shows that the hierarchy is the lowest priority is the best.
For a new tunnel with setup priority 3 and bandwidth 20 Mbps is configured it will be able to setup using R3 : gi3/0 and will cause the tunnel 6 and tunnel 7 to be rerouted.
Hope to help
Giuseppe
