This is the guaranteed minimum bandwidth, in Kbps, for this DiffServ rule, settable only for rules in the Assured Forwarding class, with the constraint that the sum across all such rules must not exceed the modem's total Tx data rate. Because Expedited Forwarding and plain Class-N rules can't have a minimum guarantee set at all, this field only matters for the Assured Forwarding rows, and an admin who over-allocates minimums across those rows beyond the link's actual capacity is setting up guarantees the modem can never honor. For example, on a 512 kbps link, setting AF1's minimum to 200 kbps and AF2's minimum to 400 kbps would exceed the link capacity and violate the documented constraint, even though each individual value falls within its own valid range.