You can configure the scheduler buffer size in three ways: as a temporal value, as a percentage, and as a remainder. On a single logical interface (MLPPP or a FRF.16 DLCI), each queue can have a different buffer size.
If you specify a temporal value, the queuing algorithm starts dropping packets when it queues more than a computed number of bytes. This number is computed by multiplying logical interface speed by the temporal value. For MLPPP bundles, logical interface speed is equal to the bundle bandwidth, which is the sum of constituent link speeds minus link-layer overhead. For MLFR FRF.16 DLCIs, logical interface speed is equal to bundle bandwidth multiplied by the DLCI shaping rate. In all cases, the maximum temporal value is limited to 200 milliseconds.
Buffer size percentages are implicitly converted into temporal values by multiplying the percentage by 200 milliseconds. For example, buffer size specified as buffer-size percent 20 is the same as a 40-millisecond temporal delay. The link services IQ implementation guarantees 200 milliseconds of buffer delay for all interfaces with T1 and higher speeds. For slower interfaces, it guarantees one second of buffer delay.
The queueing algorithm evenly distributes leftover bandwidth among all queues that are configured with the buffer-size remainder statement. The queuing algorithm guarantees enough space in the transmit buffer for two MTU-sized packets.