The CAC is enforced when an administrator bandwidth is configured on a SAP, which may be when the administrator bandwidth is initially configured or when an existing administrator bandwidth value is modified.
The CAC enforcement is achieved by comparing the newly requested SAP administrator bandwidth (the incremental administrator bandwidth being configured above any currently assigned administrator bandwidth) with the available administrator bandwidth on its port or LAG.
The operation is as follows:
If a SAP's admin bandwidth is increased and the incremental requested admin bandwidth is:
larger than the port or LAG available bandwidth then the command to increase the SAP admin bandwidth fails.
smaller or equal to the available port or LAG bandwidth then the incremental bandwidth is subtracted from the available port or LAG bandwidth.
If a SAP's admin bandwidth is reduced then the available port or LAG bandwidth is increased accordingly.
If the port or LAG admin bandwidth is increased, the available port or LAG bandwidth is increased accordingly.
If the port or LAG admin bandwidth is decreased, the available port or LAG bandwidth is decreased accordingly. However, if the resulting available bandwidth would be less than the sum of the currently allocated SAP admin bandwidth on that port or LAG, then the command to decrease the admin bandwidth fails.
If the port or LAG booking factor is decreased, the available port or LAG bandwidth is decreased accordingly. However, if the resulting available bandwidth would be less than the sum of the currently allocated SAP admin bandwidth on that port or LAG, then the command to decrease the booking factor fails.
If the SAP admin bandwidth is removed, it is excluded from the SAP bandwidth CAC function. Its admin bandwidth is added to the related port or LAG available bandwidth.
The port or LAG admin bandwidth can only be removed if all of its SAPs are excluded from the CAC function.
In the following example, a port is configured with an administrator bandwidth of 500 Mb/s, and a SAP on that port is configured with a bandwidth of 10 Mb/s. The show output displays these configured values together with the available and booked administrator bandwidth for the port. An increase of the SAP administrator bandwidth to 600 Mb/s is attempted; the operation fails because of insufficient available administrator bandwidth on the port.
The booking factor for the port is increased to 200% and the increase of the SAP administrator bandwidth to 600 Mb/s is successful as the available administrator bandwidth for the port becomes 1 Gb/s. The booked administrator bandwidth for the port is 600 Mb/s and so the available administrator bandwidth for the port becomes 400 Mb/s.
*A:PE# configure port 1/1/1 ethernet access bandwidth 500000
*A:PE# configure service vpls 1 sap 1/1/1:1 bandwidth 10000
*A:PE# show service id 1 sap 1/1/1:1 detail | match Bandwidth
Bandwidth : 10000
*A:PE# show port 1/1/1 detail | match expression "Bandwidth | BW"
Access Bandwidth : 500000 Booking Factor : 100
Access Available BW: 490000
Access Booked BW : 10000
*A:PE# configure service vpls 1 sap 1/1/1:1 bandwidth 600000
MINOR: SVCMGR #2664 Insufficient bandwidth available
*A:PE# show service id 1 sap 1/1/1:1 detail | match Bandwidth
Bandwidth : 10000
*A:PE# *A:PE# configure port 1/1/1 ethernet access booking-factor 200
*A:PE# configure service vpls 1 sap 1/1/1:1 bandwidth 600000
*A:PE# show service id 1 sap 1/1/1:1 detail | match Bandwidth
Bandwidth : 600000
*A:PE# show port 1/1/1 detail | match expression "Bandwidth | BW"
Access Bandwidth : 500000 Booking Factor : 200
Access Available BW: 400000
Access Booked BW : 600000
*A:PE#