|  | 9.1 | OSI Model
| 9.1.8 | Physical layer
The Physical Layer defines the electrical, mechanical, procedural, and functional specifications for activating, maintaining, and deactivating the physical link between end systems. Such characteristics as voltage levels, timing of voltage changes, physical data rates, maximum transmission distances, physical connections and other similar attributes are defined by physical layer specifications. Physical Layer standards include: 10BASE-T 100BASE-TX V.35 RS-232
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