Data Communication Access Methods: A Comprehensive Guide
Data Communication
Access Methods
1. Types of Access Methods
Access methods are categorized into three main types:
- Round Robin: Each station gets a chance to transmit data one at a time in a sequential manner.
- Reservation: Time is divided into segments called slots. A station must reserve a slot before transmitting and can only transmit during its reserved slot.
- Contention: There’s no fixed order for transmission. Stations transmit data whenever they have it, potentially leading to collisions.
2. Evaluating
Read MoreUnderstanding TCP/IP and Network Protocols
Introduction to Network Protocols
Overview of Operating Systems and Protocols
Windows uses TCP/IP as its native network protocol, accessible through NetBIOS. While NetBEUI was traditionally used, TCP/IP is now the standard. Linux and UNIX-based systems, including macOS X, also utilize TCP/IP as their native protocol. Novell’s NetWare operating system uses SPX/IPX. Network adapter drivers enable the operating system to communicate with the network hardware.
Common Protocol Stacks
Several protocol stacks
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Optimizing Windows Vista Performance
Disabling Unnecessary Services and Features
Much has been said about the Windows Vista operating system being heavier and slower than its predecessor, Windows XP. Many have asked about “tricks” to make Windows Vista faster and more efficient. After extensive research on Windows Vista and XP features, I’ve found several unnecessary services that start up in Vista, causing slowdowns.
Below is a list of services you can safely disable without causing problems.
Disabling
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OSI Model and Protocols
Connectionless Protocols
When connectionless protocols are implemented at lower layers of the OSI model, which layers are used to acknowledge receipt of data and solicit retransmission of missing data? B
IP Protocol and Retransmission
What OSI layer protocol does IP depend on to determine whether packets are lost and to request retransmission? E
Routing at the Network Layer
Which of the following statements are true regarding routing at the network layer? C, D, F
TCP/IP Stack Functionality
A
Read MoreCryptography and Authentication Cheat Sheet
Cryptography Cheat Sheet
General Concepts
- Cryptography: The study of encryption principles and methods.
- Cryptanalysis: The process of deciphering ciphertext without knowing the key.
- Cryptosystem: A system that combines algorithms, keys, and key management to perform cryptographic operations.
- CIA Triad:
- Confidentiality: Protects against unauthorized disclosure.
- Integrity: Protects against unauthorized modification.
- Availability: Ensures reliable access to information.
Key Terminology
- Plaintext: The original
Computer Architecture: Memory Hierarchy, Von Neumann Model & Parallel Processing
Memory Hierarchy
Memory hierarchy organizes computer memory based on speed, cost, and size, balancing fast access with large capacity. It ranges from fast, small CPU registers to slow, large storage devices.
Memory Types
Registers
Speed: Fastest memory, within the CPU.
Size: Extremely small (a few bytes).
Purpose: Stores data the CPU is currently processing.
Access Time: Nanoseconds or less.
Cache Memory
Speed: Very fast, close to the CPU, divided into levels.
Size: Small (kilobytes to megabytes).
Purpose: