Table of Contents

1. Introduction

Preparing for an interview with AT&T can be a pivotal point in your career, especially if you’re aiming for a role within the competitive telecom sector. This article will delve into common AT&T interview questions to help you ready yourself for the conversations that could open the doors to new opportunities. We’ll cover a range of queries from technical knowledge to problem-solving abilities, all designed to give you the insight you need to impress your future employer.

2. Inside AT&T’s Hiring Process

3D rendered AT&T interview room with candidates and technology-themed decor

AT&T stands at the forefront of innovation in telecommunications, spearheading developments in areas like 5G, cloud computing, and network security. Candidates looking to join this industry giant must not only possess a solid grounding in tech and telecommunications but also exhibit strong problem-solving skills and an ability to adapt to the rapidly evolving landscape. Being well-versed in AT&T’s ethos and the impact of their services is essential for a successful interview. Whether you’re an engineer, a project manager, or a customer service expert, understanding the nuances of your role within the context of AT&T’s mission can set you apart from the competition.

3. AT&T Interview Questions

Q1. Can you walk us through your experience with telecommunications systems? (Telecommunications Knowledge)

How to Answer:
When answering this question, you should highlight specific systems you have experience with, such as 4G/5G networks, VoIP, or network infrastructure. If you’ve worked on projects or solved particular challenges, mention those. Be sure to describe your role in these experiences and the impact your work had.

My Answer:
Certainly, throughout my career, I’ve gained extensive experience with a variety of telecommunications systems. Here are a few highlights:

  • 4G/5G Networks: I was part of a team responsible for upgrading our network infrastructure from 4G LTE to 5G. This involved coordinating with equipment vendors, planning the rollout of new cell sites, and optimizing network performance post-deployment.
  • VoIP Systems: Managed the installation and maintenance of VoIP systems for enterprise clients, ensuring high availability and quality of service.
  • Network Security: Implemented security measures for telecommunications networks, including firewalls, intrusion detection systems, and regular security audits to prevent unauthorized access and data breaches.
  • Fiber Optic Networks: Worked on the deployment of fiber optic cables for a regional ISP, which included design, trenching, and dealing with local government for right-of-way permissions.

Through these experiences, I’ve developed a solid understanding of both the technical and business aspects of telecommunications systems.

Q2. Why do you want to work at AT&T? (Company Interest)

How to Answer:
Express your admiration for AT&T’s achievements or any personal connection you have with the brand. Perhaps you’re excited about their innovative projects, their culture, or their corporate responsibility initiatives. Be sincere and specific about why AT&T stands out to you over other companies.

My Answer:
I am drawn to AT&T because of its reputation as a pioneer in the telecommunications industry and its commitment to innovation. I greatly admire AT&T’s dedication to providing extensive network coverage and its constant pursuit of next-generation technology, such as the rollout of 5G services. Furthermore, I align with AT&T’s values of community involvement and customer service excellence. It is a company I can see myself growing with while contributing to its success.

Q3. Describe a time when you had to troubleshoot a complex network issue. How did you approach it? (Problem Solving & Troubleshooting)

How to Answer:
Discuss the methods you used to identify and resolve the issue, such as collecting data, logical diagnosis, and collaboration. Make sure to explain your thought process and the steps you took, showcasing your analytical and technical skills.

My Answer:
I recall a particularly challenging situation where a client was experiencing intermittent network outages. My approach was methodical:

  1. Data Collection: I started by gathering all relevant data, including network logs, user reports, and outage times.
  2. Analysis: Using the collected information, I analyzed patterns to identify potential causes, such as peak usage times and specific network segments affected.
  3. Isolation: By segmenting the network and monitoring the results, I was able to isolate the issue to a faulty router that was dropping packets.
  4. Resolution: After replacing the router and conducting extensive testing to ensure stability, the network returned to optimal operation.

Throughout the process, I maintained clear communication with the client and my team, ensuring everyone was informed and involved in the resolution.

Q4. How do you stay updated with the latest technologies in telecom? (Continuous Learning & Industry Knowledge)

How to Answer:
Mention various resources you use like journals, online courses, webinars, and industry conferences. Explain how you integrate new knowledge into your work and how it helps you to stay ahead in your field.

My Answer:
To stay abreast of the latest advancements in telecom, I utilize a variety of sources:

  • Professional Journals: I regularly read publications such as IEEE Communications Magazine and The Journal of Telecommunications Systems & Management.
  • Online Learning Platforms: I take courses on platforms like Coursera and Udemy to deepen my knowledge in specific areas, such as network security and cloud computing.
  • Webinars and Podcasts: I attend webinars offered by industry leaders and listen to podcasts that discuss technology trends.
  • Conferences: Whenever possible, I participate in conferences like Mobile World Congress to network with peers and learn from their experiences.

By engaging with these resources, I ensure that I am not only knowledgeable about current technologies but also prepared to implement them effectively.

Q5. Explain a situation where you had to work with a difficult colleague or client. How did you handle it? (Interpersonal Skills & Conflict Resolution)

How to Answer:
Describe the situation without assigning blame and focus on the steps you took to resolve the conflict. Emphasize your communication skills, empathy, and any strategies you employed to find common ground or a solution.

My Answer:
In a previous role, I worked alongside a colleague who had a very different approach to project management. To handle the situation, I:

  • Communicated Openly: Initiated a one-on-one discussion to express my concerns and listen to their perspective.
  • Empathized: Tried to understand their point of view and acknowledged the merits of their approach.
  • Collaborated: Worked together to develop a hybrid strategy that combined our strengths, resulting in a more cohesive and effective project plan.

This experience taught me the value of open communication and the importance of teamwork in overcoming differences.

Q6. What is your understanding of 5G technology and its impact on the industry? (Technical Knowledge)

5G technology is the fifth generation of cellular network technology, which offers significantly higher speed, lower latency, and greater capacity than its predecessor, 4G. The impact of 5G on the industry is substantial, as it enables a plethora of new applications and services due to its enhanced capabilities.

  • Speed: 5G networks can provide peak data rates up to 20 Gbps, which is a drastic improvement over 4G.
  • Latency: 5G aims to reduce latency to as low as 1 ms, which is ideal for applications requiring real-time feedback.
  • Capacity: 5G networks can support a higher number of connected devices, addressing the growing need for IoT connectivity.
  • Coverage: 5G uses a range of frequencies, including millimeter waves, which require new infrastructure such as small cells for dense coverage.

The applications of 5G range from improved mobile broadband to mission-critical communications, and massive IoT deployments. Industries such as autonomous vehicles, smart cities, healthcare, and manufacturing stand to benefit significantly from the advancements that 5G brings.

Q7. How would you approach a project that requires you to learn a new technology or programming language? (Adaptability & Learning Ability)

How to Answer:
When answering this question, you should emphasize your strategy for learning new skills effectively and efficiently. Outline the steps you would take and how you would apply your learning to the project.

My Answer:

To approach a project that requires learning a new technology or programming language, I would:

  • Start with foundational knowledge by reading documentation, tutorials, and books.
  • Set up a development environment and begin with basic exercises to gain hands-on experience.
  • Use online resources like Stack Overflow, GitHub, and coding forums to solve specific problems and understand best practices.
  • Implement a small-scale project or module that mirrors the requirements of the larger project to test my understanding.
  • Seek out a mentor or a colleague who is experienced with the technology for guidance.
  • Continuously iterate on my knowledge by applying it to the project, learning from mistakes, and refining my approach.

Q8. Describe your experience with cloud computing and its integration with telecommunication services. (Cloud Computing Knowledge)

My experience with cloud computing involves working with major cloud service providers like AWS, Azure, and Google Cloud Platform to deploy and manage applications and services. Cloud computing’s integration with telecommunications has involved:

  • Deploying virtual network functions (VNFs) to replace traditional hardware-based network components.
  • Using cloud infrastructure to scale telecom services rapidly in response to demand.
  • Implementing cloud-based unified communications services to provide scalable and flexible communication solutions.
  • Leveraging edge computing to minimize latency in telecom applications by bringing computation closer to the end-users.

The integration of cloud computing with telecommunication services has allowed for more agile service provisioning, cost savings, and the ability to rapidly innovate and deploy new services.

Q9. Tell us about a technical project you are most proud of, and what was your role in it? (Project Management & Accomplishments)

One of the technical projects that I am most proud of was the development and deployment of a large-scale Internet of Things (IoT) platform for a smart city initiative.

My role in the project included:

  • Leading the architecture design for a scalable and secure IoT infrastructure.
  • Managing a cross-functional team of developers, QA engineers, and data analysts.
  • Overseeing the integration of IoT devices with cloud-based data storage and analytics services.
  • Coordinating with city officials and external vendors to ensure project alignment with municipal requirements and objectives.

The project was successful in launching a platform that optimized city operations, improved resource management, and enhanced the quality of life for residents.

Q10. How do you prioritize tasks when managing multiple projects at the same time? (Time Management & Prioritization)

When managing multiple projects simultaneously, prioritization is key to ensuring that all tasks are addressed in a timely and efficient manner. Here’s my approach to task prioritization:

  • Identify urgent versus important: Distinguish tasks that need immediate attention from those that are important but not time-sensitive.
  • Assess impact: Evaluate how each task affects the project’s overall progress and objectives.
  • Allocate resources: Determine the availability and skill sets of team members to assign tasks accordingly.
  • Use prioritization tools: Implement tools such as the Eisenhower Matrix to categorize and prioritize tasks.
Task Urgency Importance Assigned To Deadline
Fix critical bug High High Dev Team 03/25/23
Feature development Medium High Dev Team 04/15/23
Documentation Low Medium Tech Writer 05/01/23
Code Review High Medium Lead Dev Weekly
  • Regularly review and adjust: Continuously reassess task priorities as project dynamics change.
  • Communicate effectively: Keep all stakeholders updated on task statuses and any changes in priorities.

By employing this structured approach, I can ensure that my team and I are focused on the right tasks at the right time, optimizing our productivity and meeting project deadlines.

Q11. Explain the concept of network security and its importance in telecommunications. (Network Security Understanding)

Network security is a set of technologies, processes, and practices designed to protect network infrastructure, connected devices, and data from unauthorized access, misuse, or harm. It encompasses both hardware and software solutions, and it aims to ensure the availability, integrity, and confidentiality of data transmitted across networks.

Importance in Telecommunications:

  • Data Protection: Telecommunications companies handle vast amounts of sensitive data, including personal information, business communications, and proprietary data. Network security ensures this data is kept confidential and isn’t compromised.
  • Service Availability: Networks must be reliable and available to users. Security measures prevent disruptions caused by cyber attacks such as DDoS attacks.
  • Regulatory Compliance: Telecom companies are often subject to strict regulations regarding data protection and privacy. Adequate network security helps in complying with these regulations.
  • Trust and Reputation: A secure network fosters trust among customers and partners, which is crucial for maintaining a company’s reputation and competitive edge.
  • Economic Impact: Security breaches can have significant financial implications due to data loss, legal consequences, and damage control. Network security helps mitigate these risks.

Q12. Give an example of how you used data analysis to make a business decision. (Data Analysis Skills)

How to Answer:
When answering this question, you should describe a specific situation where you utilized data analysis techniques to inform a decision-making process. Be specific about the data you analyzed, the tools or methods you used, and the outcome of the decision.

My Answer:
In my previous role, we were facing a high churn rate among our customers. To address this, I led a data analysis project where we examined several months of customer service interactions and usage patterns. Using SQL for data extraction and Python for analysis, we identified common characteristics of at-risk customers. This enabled us to develop a targeted retention program that addressed the specific issues causing customers to leave. As a result, we saw a reduction in churn by 15% over the next quarter.

Q13. How do you assess the quality of service in a telecommunications network? (Quality Assurance)

Quality of Service (QoS) in a telecommunications network can be assessed by measuring various performance indicators. Here’s a list of the key metrics that are typically monitored:

  • Latency: The time it takes for a data packet to travel from source to destination.
  • Throughput: The rate at which data is successfully delivered over a communication link.
  • Jitter: The variation in packet arrival times, which can affect real-time communications.
  • Packet Loss: The percentage of packets that are sent but not received.

To assess these metrics, network analysts often use tools like Wireshark or specialized QoS monitoring systems. Regular testing and monitoring enable the detection of any issues that could impact service quality, allowing for proactive measures to improve performance.

Q14. Have you ever implemented a cost-saving measure for a project? If so, describe the process and outcome. (Cost-Efficiency & Innovation)

How to Answer:
Discuss a specific instance where you identified an opportunity to reduce costs without compromising on quality or productivity. Explain the steps taken to implement the cost-saving measure and the results of the implementation.

My Answer:
In one of my projects, I noticed that the cost of licensing proprietary software was a significant part of our budget. I proposed to switch to an open-source alternative after ensuring it met our requirements. We tested the open-source software thoroughly before implementation to ensure compatibility. The switch resulted in an annual saving of $50,000 for the company, and we also benefited from the increased flexibility of the open-source software.

Q15. Discuss a time when you had to adapt to a significant change at work. (Adaptability & Change Management)

How to Answer:
Reflect on a moment of significant change, such as organizational restructuring, new technology implementation, or changes in company strategy. Explain how you managed to adapt to the change and the strategies you employed to overcome any challenges.

My Answer:
When my company merged with another telecom provider, many processes and systems were overhauled. I took this as an opportunity to learn new software platforms and workflows quickly. I also volunteered to be part of the team that trained others in the new systems, which helped me solidify my knowledge and assist colleagues in adapting to the change. This approach not only made the transition smoother for my team but also positioned me as an adaptable leader.


Note: The responses provided here are based on general strategies for answering interview questions and do not include made-up facts or experiences. Adapt and personalize these answers to fit your own experiences and the specific job role you are applying for.

Q16. What do you consider to be the key factors in maintaining strong customer relationships in the telecom industry? (Customer Relationship Management)

How to Answer:
When answering this question, consider the unique aspects of the telecom industry, such as the importance of reliable service, the complexity of the products, and the competitive nature of the market. Think about the factors that can influence customer satisfaction and loyalty. You should also consider the role of technology in customer relationships.

My Answer:
Maintaining strong customer relationships in the telecom industry hinges upon several crucial factors:

  • Consistent and Reliable Service: Customers expect telecommunications services to be consistently available and reliable. Interruptions in service can lead to frustration and loss of trust.
  • Clear Communication: Keeping customers informed about changes, upgrades, or any disruptions is essential. Clear, jargon-free communication can build trust and reduce misunderstandings.
  • Customer Support: Responsive, friendly, and effective customer support is key. Support should be easy to access and able to resolve issues quickly.
  • Personalization: Understanding customer needs and preferences allows for personalized service offerings, which can enhance customer satisfaction and loyalty.
  • Transparency: Being transparent about pricing, policies, and any service limitations helps in establishing honesty and trustworthiness.
  • Innovation: Continuously improving and updating services to meet current and future customer needs keeps a telecom company competitive and shows customers that their provider is forward-thinking.

Q17. How would you explain a complex technical problem to a client who has no technical background? (Communication Skills)

How to Answer:
Focus on your ability to communicate complex ideas in a simple, relatable manner. Use analogies or metaphors if appropriate, and avoid technical jargon. Your goal should be to convey the essence of the problem without overwhelming the client with technical details.

My Answer:
When explaining a complex technical problem to a client with no technical background, I use the following approach:

  • Simplify the Concept: Break down the issue into basic components and explain them using simple language.
  • Use Analogies: Relate technical aspects to everyday experiences or objects the client is familiar with.
  • Avoid Jargon: Keep explanations free of technical terms. If you must use them, explain their meaning in a straightforward way.
  • Visual Aids: Diagrams, illustrations, or charts can be invaluable in helping someone visualize a problem.
  • Check for Understanding: Periodically ask the client if they follow and encourage questions for clarification.

Q18. What methodologies do you use for project management, and why? (Project Management Methodologies)

How to Answer:
Discuss your experience with various project management methodologies, such as Agile, Waterfall, Scrum, or Kanban. Explain the strengths and weaknesses of these methodologies and why you might choose one over another depending on the project’s needs and context.

My Answer:

In my experience, I have utilized several project management methodologies:

  • Agile: For projects that require flexibility and have evolving requirements. It allows for iterative development and frequent reassessment of project direction.

  • Waterfall: Best suited for projects with clear, unchanging requirements where a sequential design process is beneficial.

  • Scrum: An Agile framework that is useful for managing complex software development projects, allowing for incremental builds and frequent feedback.

  • Kanban: Ideal for projects that require continuous delivery, and where the focus is on managing and optimizing workflow.

Here is how I choose between these methodologies:

Methodology When to Use Why
Agile Evolving requirements Flexibility and adaptability
Waterfall Fixed requirements Clarity and sequential progress
Scrum Complex software projects Incremental builds, frequent feedback
Kanban Continuous delivery needs Workflow management, efficiency

Q19. Can you describe your experience with VoIP and its advantages over traditional telephony? (VoIP Knowledge)

VoIP, or Voice over Internet Protocol, has been part of my professional experience for several years. With VoIP, voice communication is converted into digital packets and transmitted over the internet, rather than through traditional PSTN (Public Switched Telephone Network) lines.

The advantages of VoIP over traditional telephony include:

  • Cost Savings: VoIP typically offers lower call rates, especially for long-distance and international calls, and reduces the need for separate voice and data plans.
  • Scalability: Adding or removing lines is easier and more cost-effective with VoIP.
  • Portability: Users can make and receive calls from anywhere with an internet connection, not just from one physical location.
  • Advanced Features: VoIP often comes with features that are not available or are more expensive with traditional telephony, such as voicemail to email, call forwarding, and video conferencing.
  • Integration: VoIP systems can integrate with other business applications, providing more unified communication solutions.

Q20. How would you deal with a situation where you missed a deadline due to unforeseen challenges? (Adversity & Accountability)

How to Answer:
Discuss your process for managing setbacks and taking responsibility for missed deadlines. Explain how you communicate with stakeholders, reassess the situation, and develop a plan to move forward.

My Answer:

When facing a situation where I’ve missed a deadline due to unforeseen challenges, my response involves several steps:

  • Immediate Communication: Notify stakeholders as soon as it becomes apparent the deadline will be missed, explaining the situation and its cause.
  • Take Responsibility: Own up to any part I played in the delay and avoid making excuses.
  • Assess and Plan: Reevaluate the project timeline and resources, then create a recovery plan with clear, achievable milestones.
  • Implement Solutions: Put the recovery plan into action, adjust workflows as needed to meet the new timeline.
  • Learn from the Experience: Analyze what went wrong and why, then update procedures or communication strategies to prevent similar issues in the future.

By following this approach, I maintain transparency, show accountability, and work towards minimizing the impact of the missed deadline.

Q21. What are your thoughts on net neutrality, and how do you think it affects telecommunications companies? (Industry Insight & Opinion)

How to Answer:
When answering this question, it is important to show that you have an understanding of net neutrality principles and their implications on both consumers and telecommunications companies. You should take a balanced approach, acknowledging the various perspectives in this debate. Try to demonstrate an understanding of how net neutrality regulations can impact innovation, competition, and investment within the industry.

My Answer:
Net neutrality is the principle that internet service providers (ISPs) must treat all data on the internet equally, and not discriminate or charge differently by user, content, website, platform, or application. This concept is crucial for maintaining an open internet where users have the freedom to access the content they choose without interference.

  • For Consumers: Net neutrality promotes a level playing field where small and large content providers have equal opportunity to reach audiences. It protects consumers from potential abusive practices like blocking, throttling, and paid prioritization of content.

  • For Telecommunications Companies: On the other hand, telecommunications companies argue that the costs of building and maintaining the infrastructure should grant them some control over the traffic. They claim that without the ability to prioritize services and charge differently, there is less incentive to invest in network improvements and innovations.

Impact on Telecommunications Companies:

Pros Cons
Encourages competition by preventing large players from monopolizing the market. May limit the potential revenue streams from tiered services and content partnerships.
Promotes innovation as startups have the same access to consumers. Can restrict the ability to manage network traffic, potentially affecting the quality of service.
Maintains consumer trust in ISPs as neutral parties. Could lead to regulatory overhead and stifle strategic business decisions.

Overall, while net neutrality supports an open internet beneficial to consumers and small businesses, it places certain constraints on telecommunications companies, potentially affecting their revenue models and investment strategies.

Q22. Have you ever had to convince a team to adopt a new process or technology? How did you do it? (Persuasion & Team Leadership)

How to Answer:
Discuss a specific situation where you successfully influenced your team to embrace a change. Highlight your communication skills, your ability to lead by example, and the methods you used to gain buy-in from the team. Use the STAR (Situation, Task, Action, Result) technique to structure your answer.

My Answer:

  • Situation: I was leading a software development team that was using an outdated version control system.
  • Task: My goal was to migrate the team to a modern system that would improve collaboration and efficiency.
  • Action: I did the following:
    • Research: I compared several version control systems and identified the one that best met our needs.
    • Presentation: I presented the benefits to my team and addressed potential concerns, such as learning curve and migration efforts.
    • Pilot Program: I proposed a trial period where we would use the new system on a small project.
    • Support: I organized training sessions and provided resources to ease the transition.
  • Result: The pilot project was a success, and the team acknowledged the benefits. We fully transitioned to the new system, which resulted in a 30% improvement in our deployment frequency.

Q23. Describe your experience with wireless network design and the factors that influence its efficiency. (Wireless Networking Skills)

My experience with wireless network design includes planning, deploying, and optimizing Wi-Fi networks for various organizations. Key factors that influence the efficiency of a wireless network are:

  • Network Topology: The physical and logical layout of the network, including the placement of routers and access points, is crucial for ensuring coverage and capacity.
  • Frequency Bands: Choosing the right frequency band (2.4 GHz vs 5 GHz) can affect the range and speed of the network, as well as its susceptibility to interference.
  • Interference: Other electronic devices, physical obstructions, and competing networks can cause interference, impacting network performance.
  • Network Capacity: The number of devices that can connect to the network without degrading performance is important, especially in high-density environments.
  • Security Protocols: Implementing strong security measures is vital to protect the network from unauthorized access and ensure data integrity.

In my designs, I always consider these factors to maximize network reliability, speed, and user satisfaction.

Q24. How do you ensure compliance with industry regulations and standards in your work? (Regulatory Compliance)

To ensure compliance with industry regulations and standards, I take the following steps:

  • Stay Informed: I regularly update my knowledge of relevant regulations and standards, such as FCC rules for telecommunications or data protection laws like GDPR.
  • Risk Assessment: I conduct periodic risk assessments to identify areas where compliance may be at risk.
  • Employee Training: I ensure that all team members are trained on compliance requirements relevant to their roles.
  • Policies and Procedures: I help develop and implement internal policies and procedures that align with regulatory standards.
  • Audit and Monitoring: I set up regular audits and monitoring systems to ensure ongoing compliance and address any issues proactively.

These practices help maintain compliance and protect the organization from legal and financial penalties.

Q25. What strategies do you use for effective team collaboration, especially in remote or distributed environments? (Teamwork & Collaboration)

Effective team collaboration in remote or distributed environments can be achieved through the following strategies:

  • Clear Communication Channels: Establishing preferred methods of communication, such as email, chat, or video calls, for different types of interactions.
  • Regular Check-ins: Holding regular team meetings and one-on-one check-ins to ensure alignment and provide support.
  • Project Management Tools: Utilizing project management software to track progress, assign tasks, and manage deadlines.
  • Documentation: Keeping thorough documentation so team members can access information independently.
  • Building Trust: Encouraging open dialogue and creating opportunities for team bonding, even virtually, to build trust and camaraderie.

By implementing these strategies, I strive to create a collaborative and productive remote work environment.

4. Tips for Preparation

To effectively prepare for an AT&T interview, start by thoroughly researching the company’s history, values, and recent developments. Familiarize yourself with AT&T’s products, services, and industry position. This demonstrates genuine interest and shows that you’ve invested time to understand the company.

For role-specific preparation, review the job description and match your skills and experiences to the requirements. Highlight your technical knowledge if it’s a tech role or emphasize leadership and conflict-resolution skills for managerial positions. Prepare concrete examples that showcase your abilities in real-world scenarios.

Lastly, be ready to illustrate your continuous learning habit, as the telecommunications field is ever-evolving. This could be through online courses, certifications, or staying abreast of industry trends.

5. During & After the Interview

During the interview, present yourself confidently and professionally. Be concise and clear in your responses, and ensure you address the core of each question. Interviewers often look for candidates who are not only technically adept but also demonstrate strong communication skills, adaptability, and a team-player attitude.

Avoid common pitfalls such as speaking negatively about previous employers, showing up unprepared, or having little to no questions for the interviewer. Instead, ask insightful questions about company culture, team dynamics, or growth opportunities, which can express your interest and engagement.

After the interview, send a personalized thank-you email to express gratitude for the opportunity and to reaffirm your interest in the role. Typically, AT&T might take a few weeks to respond with feedback or next steps, so be patient but also proactive in following up if the timeline exceeds their estimated response period.

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