> For the complete documentation index, see [llms.txt](https://docs.eseye.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.eseye.com/api-reference/connectivity-metrics/authentication-metrics.md). # Authentication metrics Investigate SIM network attachment events. Authentication records capture attempts by a SIM to authenticate onto the cellular network. This is the first thing that has to succeed before anything else can happen, so it is usually the first place to look when a device is silent. > **Question answered:** Did the device successfully attach to the network? ### What the records show * Initial network attach attempts. * Re-attachments following coverage loss. * Network or roaming changes. * Successful and rejected authentication events. Every attempt is captured, including the failures, you get the shape of the behaviour rather than just its outcome. A device that authenticates cleanly once looks very different from one that cycles through accepts and rejects all day, even though both may appear connected at a given moment. ### Common uses * **Identifying flapping devices:** Repeated accept and reject cycles are visible directly in the record stream, which makes it possible to find unstable devices across an estate rather than one at a time. * **Diagnosing provisioning, roaming and APN issues:** Rejection patterns and network changes narrow down whether the problem sits with the SIM configuration, the device, or the network it is trying to use. * **Correlating attach failures with later usage or session data:** An authentication record on its own tells you a device tried to connect when joined to [Accounting Metrics](/api-reference/connectivity-metrics/accounting-metrics.md), it tells you whether that attempt turned into a usable session. ### Interpretation Authentication data describes whether the device reached the network successfully. It does not show how long the resulting session remained active or where traffic travelled. Accounting and traffic flow records provide that later-stage context. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.eseye.com/api-reference/connectivity-metrics/authentication-metrics.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.