Bandwidth Control for ISPs

Hi,
I want to know how ISP allocate bandwidths for each client?
like they have a client with 128 DL kbps and another with 512 kbps DL

Another question (related): is that possible to use Frame Relay between a router and a LAN? I mean if we have a LAN with Exchange server for example and other servers, how can I limit the bandwidth for each server from the router?
Is that possible to use Frame Relay from the router that connected to same switch of servers?

regards,

It would depend on the WAN access technology being used. i.e. for FR / ATM you can set a CIR / PIR on the PVC, for Ethernet you can use Layer 2 rate limiting on the VLAN. Or if you wish to supply a full speed circuit you can limit at certain point or your network, like the egress edge - customers would have full speed within your network and then be limited as they leave, you can do this with a Layer 7 policing box - like the Cisco SCE.

For your other question I would use Ethernet and rate limit per VLAN.

Thanks.. but rate limit will not let us to use less than 1 M..
what if i want to limit each server to 128 kbps?

where do you get the 1mb limit? on my 1720 the minimum input/output rate limit value on a fastethernet subinterface is 8000 bits.

i saw it in some websites..i think thye used srr ...etc comand
could you please be more specific like show me commands and how to control both inbound and outbound connections on a certain port on the switch?

maybe (: what switch / router model are you doing this on?