Request management
========================

The request management module can select several sessions (a source node and destination node) randomly for large-scale evaluation. A ``Request`` includes the following attributions:

- ``src``: the source node
- ``dest``: the destination node
- ``attr``: the attributions of this session, such as the fidelity requirement, the QoS or the bandwidth requirement.

``QuantumNetwork`` provides ``add_request`` to manually add a new request and ``random_requests`` to randomly generate several requests:

.. code-block:: python

    # randomly generate 5 requests
    net.random_requests(number=5)

    # random generate 5 requests, but nodes can have multiple requests (allow overlay)
    net.random_requests(number=5, allow_overlay=True)

    # random generate 5 requests, with certain attributions
    net.random_requests(number=5, attr={"qos":2})

    # manually add a request
    net.add_request(Request(src=n1, dest=n3, attr={"qos":2}))

The network object and the nodes can query the related requests:

.. code-block:: python

    net.requests # get all requests

    n1.requests # get all requests related to n1
    
    n1.clear_request() # remote all requests on n1

Example applications and protocols
========================================

SimQN provides internal applications in ``qns.network.protocol``.

``BB84SendApp`` and ``BB84RecvApp`` is the simple demonstration protocol for BB84 QKD protocol without the after procedures, including error detecting, information reconciliation, and privacy amplification.

``EntanglementDistributionApp`` provides a hop-by-hop entanglement distribution protocol, where the source distribute entanglements to the destination at a fixed rate.

``ClassicPacketForwardApp`` can automatically forward all classic messages if the destination is not the current node. It will use the routing module (``qns.network.route``) to build classic routing tables.

``NodeProcessDelayApp`` can add processing delay on quantum nodes if they receive certain events.

Those examples may be helpful for users to implement their own protocols. SimQN is working on providing more internal protocols for more scenarios.