Cognizant Data Center Engineer Interview Questions, Process, and Tips

OSI Layer is a conceptual model that describes the communication functions of a telecommunication system.

• OSI stands for Open Systems Interconnection.

• It consists of 7 layers, each with a specific function.

• The layers are: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

• Each layer communicates with the layer above and below it.

• The model helps ensure interoperability between different system...read more

Hardware and software layers are part of the OSI model, which defines how data is transmitted over a network.

• Hardware layer (Layer 1) is responsible for transmitting raw bits over a physical medium.

• Software layer (Layer 7) is responsible for providing user applications with access to the network.

• Other layers in between handle tasks such as error detection and correction, routing, and data formatting.

• Examples of hardwar...read more

The heart of OSI Layer is the Transport Layer.

• The Transport Layer is responsible for end-to-end communication between hosts.

• It ensures reliable and error-free data transfer.

• It provides flow control and congestion control mechanisms.

• Examples of protocols at this layer include TCP and UDP.

A data center is a facility used to house computer systems and associated components, such as telecommunications and storage systems.

• Data centers are used to store, manage, and disseminate large amounts of data.

• They typically have backup power supplies, cooling systems, and security measures to ensure continuous operation.

• Examples of data centers include those operated by Google, Amazon, and Microsoft.

• Data centers can ...read more

There are mainly four types of data centers: enterprise, colocation, cloud, and edge.

• Enterprise data centers are owned and operated by a single organization.

• Colocation data centers are facilities where multiple organizations rent space to host their IT equipment.

• Cloud data centers are used to provide cloud services to customers.

• Edge data centers are smaller facilities located closer to end-users to reduce latency and i...read more

Uptime of data centers refers to the amount of time they are operational and available for use.

• Uptime is typically measured as a percentage of total time in a year

• Data centers strive for high uptime to ensure continuous availability of services

• Factors that can impact uptime include power outages, hardware failures, and maintenance downtime

• Industry standards for uptime include Tier I, II, III, and IV, with Tier IV offer...read more