Frequently Asked Questions (FAQ) =============================== This section addresses common questions about the NOS Testbed (NOS-T). General Questions --------------- What is NOS-T? ^^^^^^^^^^^^^ NOS-T (New Observing Strategies Testbed) is a digital engineering environment developed by NASA to facilitate the development, testing, and evaluation of new observing strategies for space missions. Who can use NOS-T? ^^^^^^^^^^^^^^^^ NOS-T is available to NASA personnel, contractors, academic partners, and other authorized users working on relevant projects. Contact the NOS-T team for access information. Is NOS-T open source? ^^^^^^^^^^^^^^^^^^ Parts of the NOS-T toolkit are open source. Please refer to the repository license for specific details on usage and distribution. Technical Questions ----------------- What computing resources are required? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ NOS-T can run on standard workstations for basic simulations. More complex modeling may require high-performance computing resources. See the installation guide for specific requirements. Can NOS-T interface with other simulation tools? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Yes, NOS-T is designed with an interoperability framework that allows integration with various external tools and models. See the API documentation for details. What messaging protocol does NOS-T use? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ NOS-T uses the Advanced Message Queuing Protocol (AMQP) for communication between distributed simulation components. AMQP is an open standard application layer protocol for message-oriented middleware focused on reliability, security, and interoperability. Do I need to understand AMQP to use NOS-T? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ A deep understanding is not necessary to start using NOS-T. However, familiarity with basic concepts like brokers, exchanges, queues, and bindings will help you work more effectively with the system. See the :doc:`../operators_guide/modules/amqpProtocol` section for more details. Where is the NOS-T broker hosted? ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The NOS-T broker is hosted on an Amazon Elastic Compute Cloud (EC2) instance. Connection details are provided during the onboarding process. Troubleshooting ------------- Simulation crashes with memory error ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This typically occurs when running complex scenarios on insufficient hardware. Try reducing the simulation fidelity or using a machine with more RAM. Cannot connect to distributed simulation ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Check your network configuration and firewall settings. The distributed simulation features require specific ports to be open. See the network configuration guide. Messages aren't being received by components ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Verify that your exchanges and queues are properly bound with correct routing keys. Check that publishers and consumers are using matching exchange types and binding patterns. Getting Additional Help -------------------- If your question isn't answered here, consider: * Checking the detailed documentation sections * Posting in the user forum * Submitting a GitHub issue * Contacting the NOS-T support team: * PI: Paul T. Grogan, `paul.grogan@asu.edu `_ * Research Scientist: Emmanuel M. Gonzalez, `emmanuelgonzalez@asu.edu `_