Incident: Tele2 Network Outage in Sweden: June 2019, Voice Calls Affected.

Published Date: 2019-07-05

Postmortem Analysis
Timeline 1. The software failure incident at Tele2 in Sweden occurred in June 2019 [87940].
System The systems that failed in the software failure incident at Tele2 in Sweden were: 1. Mobile network 2. Fixed network 3. IP-based calls These systems were affected by a combination of hardware and software faults [87940].
Responsible Organization 1. Tele2 - The software failure incident at Tele2 in Sweden was caused by a combination of hardware and software faults [87940].
Impacted Organization 1. Private customers and companies in Sweden [Article 87940] 2. Users' ability to dial emergency service numbers in Sweden [Article 87940]
Software Causes 1. The software causes of the failure incident at Tele2 in Sweden were a combination of hardware and software faults, affecting fixed, mobile, and IP-based calls [87940].
Non-software Causes 1. Hardware faults [87940] 2. Combination of hardware and software faults [87940]
Impacts 1. The software failure incident at Tele2 in Sweden resulted in a national network outage that knocked out voice calls for many private customers and companies for several hours, affecting their ability to make calls [87940]. 2. The disruption caused by the outage was particularly serious as it impacted users' ability to dial emergency service numbers, posing a potential risk to public safety [87940].
Preventions 1. Implementing thorough testing procedures for both hardware and software components to catch faults before they lead to outages [87940]. 2. Conducting regular audits and reviews of the network infrastructure to identify and address potential issues proactively [87940]. 3. Enhancing redundancy and failover mechanisms in the network to minimize the impact of hardware and software faults [87940].
Fixes 1. Conducting a thorough review of what happened and why, what actions were taken to solve the problems, and what measures are being implemented to prevent future occurrences [87940].
References 1. Tele2 spokesperson 2. CEO Anders Nilsson 3. Sweden's National Post and Telecom Agency (PTS) 4. Dutch government 5. Reporting by Esha Vaish; Editing by Anna Ringstrom and Edmund Blair 6. Our Standards: The Thomson Reuters Trust Principles. [87940]

Software Taxonomy of Faults

Category Option Rationale
Recurring one_organization, multiple_organization (a) The software failure incident having happened again at one_organization: Tele2, Sweden's second-largest telecoms company, experienced three crippling outages in the last 12 months, with the most recent outage occurring on June 17-19 [87940]. The company mentioned that the issue arose due to a combination of hardware and software faults affecting fixed, mobile, and IP-based calls. (b) The software failure incident having happened again at multiple_organization: The Dutch government launched an inquiry into an outage at telecoms company KPN in the Netherlands, which also knocked out emergency service numbers for nearly four hours. KPN blamed the outage on a software error [87940].
Phase (Design/Operation) design (a) The software failure incident at Tele2 in Sweden was attributed to a combination of hardware and software faults, indicating a failure related to the design phase of the system development. The company mentioned that the issue affected fixed, mobile, and IP-based calls, pointing towards underlying design flaws in the system [87940]. (b) The article did not provide specific information about the software failure incident at Tele2 being related to operation factors.
Boundary (Internal/External) within_system (a) within_system: The software failure incident at Tele2 in Sweden was attributed to a combination of hardware and software faults within the system. The Tele2 spokesman mentioned that the issue affected fixed, mobile, and IP-based calls, indicating an internal system failure [87940]. (b) outside_system: The CEO of Tele2, Anders Nilsson, clarified that the issue was not due to a cyber attack or security breach, suggesting that the failure did not originate from an external source [87940].
Nature (Human/Non-human) non-human_actions (a) The software failure incident at Tele2 in Sweden was attributed to a combination of hardware and software faults, indicating a non-human action as the contributing factor [87940]. (b) The CEO of Tele2, Anders Nilsson, clarified that the issue was not due to a cyber attack or security breach, suggesting that the failure was not caused by human actions [87940].
Dimension (Hardware/Software) hardware, software (a) The software failure incident at Tele2 in Sweden was attributed to a combination of hardware and software faults [87940]. The article mentions that the issue arose due to a combination of hardware and software faults affecting fixed, mobile, and IP-based calls. CEO Anders Nilsson clarified that the issue was not due to a cyber attack or security breach. (b) The software failure incident at KPN in the Netherlands was blamed on a software error [87940]. The article states that the Dutch government launched an inquiry into the outage at KPN, which knocked out emergency service numbers for nearly four hours. KPN attributed the outage to a software error.
Objective (Malicious/Non-malicious) non-malicious (a) The articles mention that the software failure incident at Tele2 in Sweden was not due to a cyber attack or security breach, indicating that the failure was non-malicious in nature [87940].
Intent (Poor/Accidental Decisions) accidental_decisions (a) The software failure incident at Tele2 in Sweden was not due to a cyber attack or security breach, as confirmed by CEO Anders Nilsson [87940]. This indicates that the failure was not a result of poor decisions related to cybersecurity measures. (b) The article mentions that the issue at Tele2 arose due to a combination of hardware and software faults, affecting fixed, mobile, and IP-based calls. This suggests that the failure was more likely due to accidental decisions or mistakes rather than intentional poor decisions [87940].
Capability (Incompetence/Accidental) development_incompetence (a) The software failure incident at Tele2 in Sweden was attributed to a combination of hardware and software faults, indicating a potential issue related to development incompetence [87940]. (b) The article did not mention any information suggesting that the software failure incident was accidental.
Duration temporary (a) The software failure incident mentioned in the articles was temporary. It caused a national network outage at telecoms company Tele2 in Sweden, knocking out voice calls for many private customers and companies for several hours [87940]. The outage lasted from June 17-19, indicating a temporary disruption rather than a permanent one.
Behaviour crash, other (a) crash: The software failure incident at Tele2 in Sweden was described as a crash where the network outage caused voice calls to be knocked out for many private customers and companies for several hours [87940]. (b) omission: The article did not specifically mention the software failure incident as an omission where the system omitted to perform its intended functions at an instance(s). (c) timing: The article did not specifically mention the software failure incident as a timing issue where the system performed its intended functions correctly, but too late or too early. (d) value: The software failure incident at Tele2 in Sweden was not attributed to the system performing its intended functions incorrectly [87940]. (e) byzantine: The article did not mention the software failure incident as a byzantine failure where the system behaves erroneously with inconsistent responses and interactions. (f) other: The software failure incident at Tele2 in Sweden was described as a combination of hardware and software faults affecting fixed, mobile, and IP-based calls, leading to the network outage [87940].

IoT System Layer

Layer Option Rationale
Perception None None
Communication None None
Application None None

Other Details

Category Option Rationale
Consequence harm, theoretical_consequence The consequence of the software failure incident reported in the articles was the potential harm to people due to the disruption of emergency service numbers. The outage at Tele2 in Sweden affected users' ability to dial emergency service numbers, which could have resulted in harm if individuals were unable to reach emergency services during critical situations [87940].
Domain information, utilities, government (a) The failed system was intended to support the information industry as it caused a national network outage at telecoms company Tele2 in Sweden, disrupting voice calls for private customers and companies [87940]. (g) The incident also affected the utilities industry as it disrupted users' ability to dial emergency service numbers, impacting power, gas, steam, water, and sewage services [87940]. (l) Additionally, the government sector was impacted as the Swedish National Post and Telecom Agency (PTS) launched an inquiry into the outage at Tele2 to investigate the disruption of emergency service numbers and ensure it doesn't happen again [87940].

Sources

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