Hi,

In frame relay there is more than one speed. First one is access speed, that is your circuit speed and is generally the same in both directions, except for satellite links and special cases.

Then you have CIR that is kind of a service guarantee for a max rate you can send and will be delivered, that would be a conservative speed for upstream, because is less (but may be equal) to access speed.

The other direction can also have same or different CIR.

Hope this helps, please rate post if it does!