CIR (Committed Information Rate); is the amount of bandwidth in bits per second (typically Kbps) that is guaranteed by the service provider in a Frame Relay network. CIR keeps the packets together during transmission from sender to receiver. In order to be able to accomplish this, a segment of the bandwidth must be guaranteed to carry these packets together.
CIR will not be affected by latency any differently than a standard, burstable link, the only difference is that the packets of information are sent together, thus arriving at their destination at the same time, avoiding the need to be re-compiled for the final transmission.