Data Collected by Endpoint Agent

This article covers the data collected by ThousandEyes Endpoint Agent.

Website Visits

While Inside a Monitored Network

If the ThousandEyes Endpoint Agent browser extension (for Chrome, Edge or IE) is installed and enabled, it monitors all page navigations within a non-incognito session. This extension extracts the following metadata (which is then displayed on the ThousandEyes application):

  • Per Page

    • Title

    • Request URL (e.g., https://example.com)

    • Request Timings (e.g., DNS resolution time, connect time)

    • Page Load Timings (e.g. page load time)

    • Response Status Code

  • Per Page Resource

    • Request URL (e.g., https://example.com/static/image.jpg)

    • Request Timings

    • Response Status Code

    • Request/Response Cookies

    • Request/Response Headers

    • Request/Response Headers Size

    • Request/Response Body Size

Also the above metadata payload does not capture the content (body) of any request/response. Therefore, the extension will never capture nor forward the following:

  • JSON/HTML/etc data sent with POST requests

  • JSON/HTML/etc data received by responses

  • X-www-form-urlencoded input data sent by form submissions

The following sensitive request/response header values are explicitly omitted (not captured) by the extension:

  • Set-Cookie

  • Cookie

  • Authorization

While Outside a Monitored Network

No data is automatically collected while an Endpoint Agent communicates with ThousandEyes from outside a monitored network. Manual recording may still be initiated by the endpoint user, targeting ANY (monitored or unmonitored) domain. These results will be collected and reported back to ThousandEyes and will appear in the Endpoint Agent views.

Web Performance Data (Web and Session Details Views)

Web Performance data includes HTTP Archive (HAR) format data. HAR information collected by the Endpoint Agent includes each file accessed on a particular site, and includes request and response header information, timing, source and destination IP addresses, as well as wait and receive timing for each component loaded in each page visited. Sensitive information in headers (such as cookie information and authorization data) is suppressed at collection time.

For more information on the content of HAR format data, refer to http://www.softwareishard.com/blog/firebug/http-archive-specification/

Waterfall data is shown for each page visited. A “session” constitutes either:

  • a user visit to a domain, using a specific protocol (ie, http://www.google.com and https://www.google.com would be separate sessions, since the protocol differs between the two domains, however, multiple subsequent visits to https://www.google.com would be recorded in the same session)

  • a manual recording initiated by an endpoint user - the session will last from the first page that the user clicks the record button through the last page of the recording.

A waterfall (“page”) will be captured each time the DOM is reloaded in a session (ie, navigation to another page, form submission and/or page refresh). Multiple pages can be shown in a single session.

Network Data (Network and Session Details Views)

Network data is collected in a number of different ways, and differs from data captured by the ThousandEyes Enterprise Agent. A detailed list of each series of packets sent is shown below.

Network probes are done in the following ways:

  • ICMP ping: Sends 10 ICMP packets with 1 second interval. The round trip time (RTT) is captured and the sent/received ratio.

  • ICMP path trace: Performs an ICMP-based TTL path trace with a maximum of 32 hops. Information about each hop is captured, including RTT. If the Endpoint Agent is running on a Mac OS X client, MPLS information will also be captured and shown

  • TCP connect: Opens a TCP connection with a 10 second timeout and closes the connection if it was able to connect. Timing, and error code (if applicable) is captured.

  • TCP ping: This probe conceptually does not differ much from the ICMP-based one - the difference in the implementation can be found here.

  • TCP path trace: The network measurement done in this probe is similar to the ICMP-based TTL path trace but the differences can be found here.

Network Data for Scheduled Tests

The configuration option (protocol) determines what network probes are sent to collect the network data:

Network Data for Local Networks

Based on the connection topology of the Endpoint, network probes will be sent to the following destinations:

Computer Information (Session Details View)

Some information about the computer where the Endpoint Agent is installed is collected as well.

Network Information (Session Details and Network Topology Views)

In addtion to the computer information, the following network information is collected

Local Network Information (Network Access and Wireless)

The following data is continuously collected while the endpoint is active:

**Retransmisssion Rate** - The retransmission rate counter is not supported for Endpoint Agents installed on macOS as the information needed to calculate a retransmission rate is not publicly available on macOS.

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