i would like to ask what the total bandwidth performance means for a supervisor engine . For example II plus 10 GE engine support 108Gbps , is this the total bandwidth that can aggregate for a lan ?
It means that the switch fabric can support up to 108Gbps of throughput. It's like the Sup720 being able to support up to 720Gbps switch fabric.
How much throughput you get on the switch is totally dependant on which linecards you use. If the total throughput of your linecards does not exceed 108Mbps and each individual linecard does not exceed it's allocated bandwidth then you are non-blocking on the switch fabric.
The bandwidth your reading is what's offered by the fabric/backplane of the switch. Often switches will offer less internal bandwidth than all the connection ports could use.
A switch with 48 gig ports would require 96 Gbps of bandwidth (2x for duplex traffic).
The original 4500 chassis provides 6 Gbps per line card slot. A 4506 or 4607R each have 5 card slots, (6 Gbps * 5 slots * 2 duplex =) 60 Gbps. The dual 10 gigs is 40 Gbps. The 4 gig ports on the sup2+-10GE is another 8 Gbps. This combined 108 Gbps corresponds to the values seen in Table 1 in: http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps4324/product_data_sheet0900aecd80356bde.html