# Topic covered
* Network Devices
* Repeater, Hub, Bridges, Switch, Router Modem
* Client, Server, Host, Noise, Distortion
* Who governs the Internet?
* Internet, Intranet and Extranet
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02-CN Fundamentals
OSI and TCP/IP model
# Topic covered
* OSI Model
* Physical, Data-link Layer
* Network Layer
* Transport Layer
* Session, Presentation, Application Layer
* TCP/IP model
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01-CN Fundamentals
CN Types, Transmission Medium and Modes, Network Topology
# Topic covered
* Computer Network
* Types of computer networks
* PAN, LAN, CAN, MAN, WAN
* Types of Transmission Media
* Guided Media
* Unguided Media
* Transmission Modes in Computer Networks
* Simplex, Half-Duplex, Full-Duplex
* Types of Network Topology
* P2P, Bus, Ring, Star, Tree, Mesh, Hybrid
* Data Transmission
* Unicast, Broadcast, Multicast
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08-Operating Systems
Non-contiguous Allocation, Virtual Memory
Non-contiguous Allocation
- The non-contiguous memory allocation also reduces memory wastage caused by internal and external fragmentation.
Paging
andSegmentation
are the two ways that allow a process’s physical address space to be non-contiguous.
07-Operating Systems
Contiguous Memory Allocation, Logical versus Physical Address
Memory Management Techniques
Logical versus Physical Address Space
- Logical Address
- An
address generated by the CPU
while a program is running - The logical address is basically the address of an instruction or data used by a process.
- User can access logical address of the process.
- User has
indirect access to the physical address through logical address
- Logical address does not exist physically. Hence,
aka, Virtual address
- The set of all logical addresses that are generated by any program is referred to as
Logical Address Space
- Range:
0 to max
- An
06-Operating Systems
Deadlock(Prevention, Avoidance, Detection, Recovery)
Deadlock
- A situation where a set of
processes are blocked
because each process isholding a resource and waiting for another
resource acquired by some other process. - This block situation is
called Deadlock(DL)
- DL is a bug present in the process/thread synchronization method
- In DL, processes never finish executing, and the system resources are tied up, preventing other jobs from starting.
05-Operating Systems
Concurrency, Concurrency Problem, Synchronization Problem
Concurrency
- Concurrency is the
execution of the multiple instruction sequences at the same time
. - It happens in the operating system when there are
several process threads running in parallel
04-Operating Systems
CPU Scheduling in Operating Systems
CPU Scheduling in Operating Systems
- Short-term schedular
- Move processes from:
Ready Queue (Ready state)--> Running state
- CPU scheduling can be of two types
Non-Preemptive
schedulingPreemptive
scheduling
03-Operating Systems
32-Bit vs 64-Bit OS, Storage, Process(PCB, Life Cycle, Schedular)
32-Bit vs 64-Bit OS
- A 32-bit OS
has 32-bit registers
, and it can access 2^32 unique memory addresses.- i.e.,
4GB
of physical memory.
- i.e.,
- A 64-bit OS
has 64-bit registers
, and it can access 2^64 unique memory addresses.- i.e.,
17,179,869,184 GB
of physical memory.
- i.e.,
- 32-bit CPU architecture can process 32 bits of data & information.
- 64-bit CPU architecture can process 64 bits of data & information.
02-Operating Systems
Kernel & User Space, IPC, System calls, BIOS/UEFI, PC ON process
Components of OS
Kernel
- A kernel is that part of the operating system which
interacts directly with the hardware
and performs the most crucial tasks. - Heart of OS/Core component
- Very first part of OS to load on start-up.
- A kernel is that part of the operating system which
User space
- Where application software runs,
apps don’t have privileged access
to the underlying hardware. It interacts with kernel. - App: GUI, CLI
- Where application software runs,