The best value for the sequence multiplier is one that is no larger than it needs to be but ensures that there is no wrap-around of sequence numbers as contained in the available Multiple-Use bits of a Burst Control Word.
If the channel extension is set to 256 channels, the multiplier is found by satisfying the following equation:
If the multiplier is 1, the buffer should be no deeper than 252 which ensures no sequence number appears more than once in the buffer when minimum sized bursts are stored. If the multiplier is 2, the buffer should be no deeper than 504 which ensures no sequence number appears more than twice in the buffer when minimum sized bursts are stored.
If the multiplier is 4, the buffer should be no deeper than 1008 which ensures no sequence number appears more than four times in the buffer when minimum sized bursts are stored, and so forth.
If the channel extension is set to something greater than 256 channels, the number of bits available for sequence numbers in the Multiple-Use bits of a Burst Control Word is reduced. Thus, if the channel extension is set to 512 channels, the multiplier is found by satisfying the following:
If the channel extension is set to 1024 channels, the multiplier is found by satisfying the following:
If the channel extension is set to 2048 channels, the multiplier is found by satisfying the following:
Both the TX and RX link partners must be assigned the same multiplier.