What Does End-to-End Testing Mean for Telecoms?

The digitization of telecommunications has led to the adoption of many software testing methodologies, including end-to-end (E2E) testing. Sometimes confused with system testing, E2E testing goes much farther, validating the interoperability of different network components and their complex interactions.

Telcos often treat E2E testing as a necessary evil, an expensive and labor intensive process that doesn’t always deliver clear ROI. But automating E2E testing can help overcome some of its challenges.

The Purpose of E2E Testing

The testing team already conducts thorough and thoughtful tests on individual units, systems, and integrations. So you’d think that everything would interact as designed, right? Not always.

Sometimes there are “communication breakdowns” between different network components, which must seamlessly share command and data information. These timing and content issues often emerge only in the context of E2E testing. Essentially, E2E testing ensures that the whole network ecosystem works as more than simply the sum of its parts.

E2E testing should focus on real-user scenarios and validate a system and its individual components for not only integration, but also data integrity. When executed well, E2E testing detects issues with components, subsystems, and workflows, contributing to increased efficiency and reliability of the entire system.

Challenges of E2E Testing

E2E testing requires complex test scenario planning. In a perfect world, the test team would have a comprehensive, detailed list of conditions for every single user function. But in reality, the time and resources required for manual testing usually mean that E2E testing can only be completed for some user stories.

Since other tests should catch many critical issues, this selective E2E testing can be adequate. However, more complete E2E testing is naturally preferable. Automation of E2E testing can help telcos attain a more thorough, rigorous E2E testing protocol, along with reducing the costs associated with manual E2E testing. However, automation can present its own set of challenges:

• Scalability: E2E testing protocols will continue to become more complex in the coming years. And every change to a mission-critical system means that the E2E test must be updated and documented. While this increased demand makes automation absolutely critical, tests much also be run in parallel, demanding more resources.
• Coordination: Workflows for E2E tests must be scheduled in the same sequence they would be executed in the real world. The intricate interdependencies of all these systems can be difficult to manage across diverse testing scenarios. 
• Accessibility: E2E tests run across entire systems in a pre-production environment, and often each system is administered by a different team. Once tests are automated, individual testers lose the ability to improvise in the case of exceptions, because they can’t access the E2E test itself.

Best Practices in E2E Testing Automation 

These challenges shouldn’t deter telcos from automating E2E testing; the potential benefits far outweigh these challenges. Following best practices can help maximize the advantages of automated E2E testing.

• Put end users first. Design E2E tests with user stories, acceptance tests, and behavior-driven design (BDD) in mind. This approach helps to keep the focus on features, rather than implementation. 
• Stick to the “happy path.” Focus on high-use cases that represent typical use-case scenarios. These are sometimes called the “happy path” or “golden path.” Limit exception testing to lower unit- or integration-level testing. 
• Remember your risk analysis. E2E testing is expensive. Focus on features that are high-risk, that is, those that are more likely to fail and will also have significant impact on customer experience. 
• Choose the right framework. Look for a testing automation partner that offers full access to systems under test. That access should include signaling trace and system log analysis.

• Use a common-sense testing sequence. When you test a single application, it’s relatively easy to diagnose and fix a failure. But E2E testing looks at much more complex systems, so identifying the root cause of a failure can be much more difficult. Save E2E testing for last, after more straightforward testing has been used to address most bugs.

• Create the ideal testing environment. Build an efficient test environment, thoroughly document its requirements, and communicate those requirements to the entire testing team. Be sure to address how to handle updates and other changes. 

• Concentrate on the most common devices. Given the vast variety of connected devices, E2E testing on every device is basically impossible. Use the most popular iOS and Android devices for physical testing, and use simulations or emulators for less popular devices.

• Avoid direct interaction with user interfaces (UI). Changes in UI can cause test failure. By separating your test logic from UI elements, you’ll get a more stable test. When a test must interact with UI, be sure to set wait times just a bit longer than it should normally take for a UI element to appear. That way the test won’t fail unnecessarily due to brief UI-related delays. 
• Account for manual testing needs. Not everything can be automated; testing usability, for example, will remain a manual task. Don’t forget to account for the cost and time associated with this manual testing.