In layered systems, PDU represents a unit of data specified in the protocol of a given layer, which consists of protocol control information and user data. PDU is a significant term related to the initial four layers of the OSI model. In Layer 1, PDU is a bit, in Layer 2 it is a frame, in Layer 3 it is a packet and in Layer 4 it is a segment. In Layer 5 and above, PDU is referred to as data.
During Reconstruction, however, the conflict over labor resulted in the sharecropping system, in which black families would rent small plots of land in return for a portion of their crop, to be given to the landowner at the end of each year.nstead of receiving wages for working an ownerâs landâand having to submit to supervision and disciplineâmost freedmen preferred to rent land for a fixed payment rather than receive wages. By the early 1870s, the system known as sharecropping had come to dominate agriculture across the cotton-planting South.
After deducting the cost of supplies for which the owner had paid, the owner shared the remaining profits with the sharecroppers. Sharecroppers usually received between one-third and one-half of the remaining profits. When the weather was poor or prices for the crops were low, profits often did not cover much more than the cost of supplies. Sharecroppers frequently wound up in debt. Sharecroppers who managed to make a profit and save money eventually gained more independence as farmers.