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Operating System (OS)

• Set of software that manages the hardware and provides services to computer programs.

• Cycle Hardware<OS<Application<User.• Real-time OS are for executing real-time applications• It is predictable response to Events. Has two aspects:

a) Event Driven b) Time Sharing

• Distributed OS: Many appear as 1 computer• Embedded OS: For embedded computer System.

Different Operating Systems

• Unix: All Console• Linux: GUI of Linux• Mac: As known• Windows: As known• Android: Mobile OS, Linux wrapped in Java• AIX: Customized Unix by IBM• HP-UX: Customized Unix by HP• Solaris: Customized Unix by Sun Microsystems

Architecture (Kernel OS)

OSI Model For Networking

OSI vs Internet

Middleware

• Computer Software that provides services to software applications beyond Operating System.

• It makes it easier for developer to perform communication (I/O) so that they focus on purpose of application.

• Communication & Mgmt of data ‘Dash in client- server’

• Software layer that lies between OS & Application.

Development Skills

• Languages: Assembly, C, C++, Java, .Net

• Difference between C & C++.

• OOPS

• Module Prog. & S/W architecture.

• Algorithm & its Optimization.

• Scripting: Perl, Shell, Tcl, Python.

Software Testing• Black-Box Testing: Internal System design not considered but based on

Requirement and functionality. (Not so strong).• White-Box Testing: Internal Logic, mainly codes (Strong).• Unit Testing: Components & modules.• Integration Testing: Bottom Up approach.• Functional Testing: Output as per Req.• System Testing: Entire system is tested as per requirement.• End to End Testing: Similar to System, but involves real world testing

(database,network,hardware).• Sanity Testing: Testing of Software versions.• Regression Testing: Testing whole application if any change in module or

functionality.• Acceptance Testing: System meeting customer requirements.• Load Testing: Testing system under load.• Stress Testing: System is stressed beyond its application.(data,query,connections).• Performance Testing: How system performing under different loads.• Usability Testing: Is customer understanding the system.

• Install/Uninstall testing: Recovery from crash and hardware failure.

• Security Testing: Penetrating via hacking.

• Compatibility Testing: Working on all platforms.

• Manual Testing: Strong/Values.

• Automation Testing: Test cases,Scripting,Automation.

Security Concepts

• IPSec: Internet Security Protocol is a protocol suite for securing IP by:

a) Authenticationb) Encrypting each IPv4 & v6 packet• Works on Internet Layer or Upper Layer.• SSL: Secure Socket Layer• TLS: Transport Layer Security• SSH: Secure Shell

IPSec Uses Following Protocols

• Authentication Header

• Encapsulating Security Payloads (ESP).

• Security Associations.

• Common Terms:

• Algorithm, Intergrity, Authentication, Keys,

Encapsulation,Encryption,Protocols.

Thanks

Any Questions?