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 harvesting the crop, the tenant sold it and received income from it. From that income, he paid the landowner the amount of rent owed. Sharecroppers seldom owned anything. Instead, they borrowed practically everything â not only the land and a house but also supplies, draft animals, tools, equipment, and seeds. The sharecropper contributed his, and his familyâs, labor. Sharecroppers had no control over which crops were planted or how they were sold. After harvesting the crop, the landowner sold it and applied its income toward settling the sharecropperâs account. Most tenant farmers and sharecroppers bought everything they needed on credit from local merchants, hoping to make enough money at harvest time to pay their debts. Learn more about the crop-lien system.