ABSTRACT
Layer 1 of the OSI model is responsible for carrying an electrical current through the computer hardware to perform an exchange of information. The physical layer is defined by the following parameters:
• Bit transmission rate
• Type of transmission medium (twisted-pair, coaxial cable, or fiber-optic cable)
• Electrical specifications, including voltage-or current-based, and balanced or unbalanced
• Type of connectors used (normally RJ-45 or DB-9)
• Many different implementations exist at the physical layer
Installation Considerations
Layer 1 can exhibit error messages as a result of overusage. For example, if a file server is being burdened with requests from workstations, the results may show up in error statistics that reflect the server’s inability to handle all incoming requests. An overabundance of response timeouts may also be noted in this situation. A response timeout (in this context) is a message sent back to the workstation stating that the waiting period allotted for a response from the file server has passed without action from the server.
