Question : Can Cisco 3550 use for rate-limit ???

Hi,
  Does anybody know how to limit bandwidth consumption with Cisco 3550 ???
 Or what kind of Layer-2 switch which can be used to limit bandwidth ???
   I heard that have a zone of Carrier or ISP using Layer-2 switch for rate-limit ,do you know what kind  of equipment they're using ???
  Show me how ,thanks !!!!

Cheers !!  

Answer : Can Cisco 3550 use for rate-limit ???

You should be able to do that with the 3550, although what you're asking is a layer 3 function, not layer 2.
The SMI feature set includes advanced QoS, rate-limiting, access control lists (ACLs), and basic state and RIP routing functionality. Use the Police function to set bit rates:
http://www.cisco.com/univercd/cc/td/doc/product/lan/c3550/12113ea1/3550cr/cli1.htm#1864073

If you want up to Gigabit, check out the Cisco 3750. You can specify individual port rates in 8k increments.

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_data_sheet09186a0080161371.html

Granular rate limiting
 Cisco Committed Information Rate (CIR) function guarantees bandwidth in increments as low as 8 Kbps.
Rate limiting is provided based on source and destination IP address, source and destination MAC address, Layer 4 TCP/UDP information, or any combination of these fields, using QoS ACLs (IP ACLs or MAC ACLs), class maps, and policy maps.
Asynchronous data flows upstream and downstream from the end station or on the uplink are easily managed using ingress policing and egress shaping.
Up to 64 aggregate or individual policers are available per Fast Ethernet or Gigabit Ethernet port.