CESC Limited Telecom Analyst Interview: Rounds, Questions and Preparation

What the job involves

A Telecom Analyst monitors network performance, analyses call and data traffic, and supports planning and optimisation of telecom and internet services. In a company like CESC Limited, which runs its own communication infrastructure alongside power distribution, the role often involves tracking leased lines, fibre links, bandwidth usage, and service uptime for internal and customer-facing operations. Day to day work includes pulling data from network management systems, preparing reports, coordinating with field and NOC teams, and suggesting fixes for congestion, outages, or poor quality of service.

Role and Telecom Sector Knowledge

1. 1

   What does a Telecom Analyst do differently from a network engineer in a company that runs both power and telecom infrastructure?

   Explain that the analyst focuses on data, monitoring, reporting, and optimisation, while the engineer configures and maintains equipment. Mention that in a utility-like setup, the analyst often tracks both internal communication links and customer-facing internet services.

2. 2

   Which key performance indicators would you track for a leased line or broadband service, and why?

   Cover uptime, latency, jitter, packet loss, throughput, and mean time to repair. Link each KPI to customer experience, such as video calls needing low jitter and low latency.

3. 3

   How does the telecom regulatory environment in India affect the day-to-day work of a telecom analyst?

   Mention TRAI guidelines on quality of service, tariff reporting, and interconnection. Explain that analysts may need to prepare compliance or QoS reports and flag issues before they become regulatory concerns.

4. 4

   What is the difference between a circuit-switched and a packet-switched network, and why does it matter for internet services?

   Define circuit switching as dedicated paths, like traditional voice, and packet switching as shared, statistical multiplexing used for data. Explain that modern voice over LTE and internet traffic mostly ride on packet networks, so analysts focus on packet-level metrics.

Technical Fundamentals and Tools

1. 5

   Explain how you would use SNMP and syslog data to investigate a link that keeps flapping.

   Describe checking SNMP interface counters for up and down transitions, error rates, and CRC errors, then correlating with syslog messages for power or hardware faults. Mention escalating to field teams with timestamped evidence.

2. 6

   A customer reports slow internet during peak hours. What technical factors would you check first?

   Check bandwidth utilisation on the last-mile and backhaul, latency and packet loss to the gateway, and whether the issue is local or upstream. Mention comparing peak and off-peak baselines.

3. 7

   What is subnetting, and why would a telecom analyst need to understand it?

   Explain that subnetting divides an IP network into smaller logical networks. Analysts need it to read IP plans, identify overlapping ranges, and understand routing or addressing issues in reports.

4. 8

   How would you calculate Erlang and use it in traffic analysis?

   Define Erlang as a unit of traffic intensity, one Erlang being one circuit busy for one hour. Explain using it to estimate trunk or channel requirements and to compare busy-hour traffic against capacity.

Practical Scenarios and Problem Solving

1. 9

   You notice a sudden 40 percent drop in throughput on a fibre link but no alarm on the NMS. What steps do you take?

   Start with historical baselines, check for recent configuration changes, test with ping and traceroute, and inspect optical power levels. Mention coordinating with field teams for physical checks if logical checks are clean.

2. 10

   A new broadband plan is being launched for a small town. What data would you gather to plan capacity?

   Cover expected subscriber count, usage patterns, peak-hour concurrency, last-mile technology options like GPON or wireless, and backhaul availability. Mention building a simple traffic model and a growth buffer.

3. 11

   During a major outage, you have limited information and multiple teams asking for updates. How do you prioritise?

   Describe establishing a single source of truth, triaging by affected users and critical services, and sending short, regular updates. Mention documenting the timeline for a post-incident review.

4. 12

   How would you validate whether a reported improvement in network performance is real and not just a reporting error?

   Suggest cross-checking multiple data sources, comparing before and after periods with the same measurement method, and checking for changes in counters or sampling intervals. Mention involving a second analyst for review.

Behavioural and HR Questions for Freshers

1. 13

   Telecom operations often involve shifts or on-call support. How would you handle that as a fresher?

   Show awareness of 24x7 operations, give an example of adapting to a demanding schedule during college or projects, and mention prioritising health and handover discipline.

2. 14

   Tell us about a time you had to explain a technical issue to someone with no technical background.

   Use a simple project or lab example, describe how you avoided jargon, used analogies, and confirmed understanding. Relate it to explaining network issues to non-technical stakeholders.

3. 15

   Why do you want to work in telecom and internet services rather than pure IT or software?

   Connect your interest to connectivity as a basic service, the mix of field and desk work, and the visible impact on customers. Mention specific topics like 5G, fibre expansion, or rural broadband that excite you.

4. 16

   Describe a time you found a mistake in your own work or data. What did you do?

   Choose a real example, explain how you detected it, corrected it, and changed your process to prevent recurrence. Emphasise honesty and attention to detail, which matter in network reporting.