I have a requirement to rate limit one of the customer to 40Mbps. Unfortunately I have to do it in Cisco router. The customer is landed on POS interface with encapsulation configured as FR. Customer has got 2 services so 2 different DLCI are used. In one DLCI, 40Mbps CAR is configured. Whenever there is a flap in the POS interface the router has very high CPU. I guess configuring CAR makes the router to do a process switch of every packet it receives.
If policing is configured rather than CAR does it reduce the load on CPU. Because class-map and policy-map works on CEF and it reduces load on CPU.
Would like to know:
1. When CAR is configured, router does Process switching or still does CEF. How about the load on CPU.
2. If policing is configured, router does CEF. But how about the load on CPU. Will it be the same like CAR or somewhat better.
thanks in advance