The Open Systems Interconnection (OSI) model describes a conceptual framework that standardizes the communication functions of a computer network. The OSI model comprises seven layers, each of which has a specific function in the communication process. By breaking down the communication process into separate layers, the OSI model ensures that each layer performs a specific function, and that the layers work together to ensure the integrity of data communications. Here are the seven layers of the OSI model and their functions: 1. Physical Layer: This layer is responsible for the transmission of raw bits over a physical medium, such as copper wires, fiber optic cables or radio waves. 2. Data Link Layer: This layer provides error-free transfer of data frames between nodes over the physical layer. Functions included in this layer include error detection, flow control, and access control. 3. Network Layer: This layer helps to route data between different networks. It is responsible for receiving packets from the data link layer, adding the logical address (such as an IP address) and forwarding the packet to the next node along a path. 4. Transport Layer: This layer is responsible for end-to-end error-free data transfer between systems. It ensures that data is broken into smaller chunks known as segments, and that each segment arrives at the destination location in the correct order. 5. Session Layer: This layer manages the communication sessions between hosts. It establishes, maintains, and terminates communication sessions, and ensures that communication session integrity is maintained in the event of a failure or error. 6. Presentation Layer: This layer ensures that the data being exchanged between systems is in a format that can be interpreted by the receiving system. This layer is responsible for content encryption, compression, and decryption. 7. Application Layer: This layer provides services that directly access all other layers of the OSI model. It is the top-most layer and includes application programs such as web browsers, email clients, and instant messaging applications. By breaking down the communication process into these distinct layers, the OSI model ensures that each layer performs a specific task, making it easier to troubleshoot problems, and ensures that data communication is standardized and remains reliable, secure, and scalable. <<<<END>>>>> The Open Systems Interconnection (OSI) model is a conceptual model that is used to describe how different computing systems can communicate with each other over a network. It is divided into seven abstraction layers, each of which is responsible for different aspects of the communication process. Starting from the lowest layer, the layers are: 1. **Physical Layer:** The physical layer is responsible for transmitting raw bits over a communication channel. It defines the electrical, mechanical, and procedural aspects of the physical connection. 2. **Data Link Layer:** The data link layer is responsible for transmitting data frames between adjacent network nodes over a physical layer connection. It ensures that the data is error-free and the transmission is reliable. 3. **Network Layer:** The network layer is responsible for routing network traffic between different network nodes. It provides logical addressing and routing services and enables inter-network communication. 4. **Transport Layer:** The transport layer is responsible for establishing end-to-end connections between network applications. It provides reliable transmission and flow control services. 5. **Session Layer:** The session layer is responsible for managing communication sessions between applications. It provides mechanisms for session establishment, maintenance and termination. 6. **Presentation Layer:** The presentation layer is responsible for translating data between application formats and network formats. It handles data compression, encryption and decryption. 7. **Application Layer:** The application layer is the layer closest to the end user. It provides services that directly support user applications such as email, web browsing, and file transfer. Each layer communicates with its adjacent layers to ensure that data is properly transmitted and received. The lower layers handle the technical aspects of communication, while the upper layers handle the application-specific aspects. By dividing communication into these distinct layers, the OSI model ensures that data communications are reliable and efficient. <<<END>>>> The Open Systems Interconnection (OSI) model is a conceptual framework used to describe the functions of a networking system. It consists of seven layers, each of which performs a specific function in the process of network communication. Here is a brief overview of each layer and the protocols associated with them: 1. Physical layer: This layer deals with the physical connection between devices and the transmission of data. This includes the specification of cables, connectors, and signaling. Protocols at this level include Ethernet, Wi-Fi, and USB. 2. Data link layer: This layer is responsible for the reliable transmission of data across a physical medium. It ensures that data is transmitted without errors and handles the flow of data. Protocols at this level include ARP, MAC, and PPP. 3. Network layer: This layer deals with the routing of data across multiple networks. It determines the path that data takes to reach its destination, and handles fragmentation and reassembly of data. Protocols at this level include IP, ICMP, and IGMP. 4. Transport layer: This layer provides end-to-end communication between devices on the network. It ensures that data is transmitted reliably and handles congestion control. Protocols at this level include TCP, UDP, and SCTP. 5. Session layer: This layer manages the communication between applications running on different devices. It establishes, maintains, and synchronizes communication sessions between devices. Protocols at this level include TLS, SSL, and NetBIOS. 6. Presentation layer: This layer handles data encryption, decryption, compression, and decompression. It ensures that data is in a format that can be easily understood by the receiving device. Protocols at this level include MIME, SSL, and JPEG. 7. Application layer: This layer contains protocols used by specific application programs. It enables communication between application programs running on different devices. Protocols at this level include HTTP, FTP, and SMTP. Each layer of the OSI model has its own set of functions and protocols that work together to ensure reliable communication between devices on a network. <<<< end>>>>>> Based on the provided search results, it seems that you have pasted a question related to a network solution for Netcare Hospital. Here are the answers to the specific questions within the question: 2.1.1. The business requirements of Netcare Hospital are to have a network solution that allows medical staff to access medical systems from any patient room, including patient medical records, x-rays, and prescriptions. 2.1.2. There is no mention of any specific financial constraints in the question. 2.1.3. The technical requirements of the network include having highly available servers, having secure WLAN access on floors 6-10, and reducing the reliance on Class C networks. 2.1.4. The technical constraints of the network include slow server access and the need for faster switches to provide faster access to the servers. 2.1.5. A logical diagram of the existing network would require additional information not provided in the question, such as the exact layout and components. 2.1.6. To improve the switching speed between floors, one approach could be to use distributed switching with edge switches on each floor connected to the core switch. 2.1.7. An IP addressing scheme that reduces the reliance on Class C networks could include using Class B or Class A networks, depending on the size of the hospital's network. 2.1.8. Recommendations for routing protocols could include using Routing Information Protocol Version 2 (RIPv2) for faster convergence and support for Variable-Length Subnet Masks (VLSM). 2.1.9. Recommendations for WLAN access and network upgrades could include upgrading to faster access points and wireless controllers, implementing quality of service (QoS) policies to prioritize medical traffic, and using security protocols such as WPA2 with AES encryption. 2.1.10. An example proposed network solution diagram could include a core switch connected to edge switches on each floor, with separate VLANs for medical staff and patients, and separate subnets for wired and wireless traffic. The servers would be housed in a separate secure data center segment, and redundant links and power supplies would be implemented for high availability.