Need Explanation on data link layer..

I need explanation on few things.

1. Data rate.
2. Maximum transmission units

and another thing which is confusing me is abut "Data Link Layer"

Data link layer has 2 sub layers that is
1. MAC Sublayer
2. LLC Sublayer.

i shall be very thankful if any friend explain me these things in detail
specially about "MAC & LLC" sublayers


Waiting for Answer
GOD bless u all

Not sure what you mean by Data Rate, but if you mean the bandwidth - this is the links bandwidth.

MTU - Maximum Transmission Unit: This is the largest for a packet. If your packet is larger than this, it will be split into 2 or more packets (or datagrams).

As far as the Data Link Layer, you can get a pretty good explanation on this under the Networking Menu at Networking/The OSI Model/OSI Layer 2.

Anything problems give us a shout.

Tom.