Experiment

Configuration

Mini-NDN uses a configuration file describing the topology and its parameters to setup a network.

The [nodes] section:

At the bare minimum, the node section describes the nodes present in the topology.

[nodes]
a: key1=value1 key2=value2
b: key1=value1

Any key and value passed here is accessible in Mini-NDN as:

ndn = Minindn(...)
value = ndn.net.hosts[0].params['params'].get('key1', "defaultValue")

One can specify log levels for each node’s NFD and NLSR using this key-value system:

[nodes]
a: nfd-log-level=DEBUG nlsr-log-level=DEBUG
b: nfd-log-level=INFO

To specify a log level for certain modules of NFD, the following line can be added to nfd.py:

node.cmd('infoedit -f {} -s log.Forwarder -v {}'.format(self.confFile, 'INFO'))

This will turn on FORWARDER logging to INFO for all nodes.

The [links] section:

The links section describes the links in the topology.

e.g.)

[links]
a:b delay=10ms

This would create a link between a and b. ‘b:a’ would also result in the same. The following parameters can be configured for a node:

  • delay : Delay parameter is a required parameter which defines the delay of the link (1-1000ms)
  • bw : Bandwidth of a link (<1-1000> Mbps)
  • loss : Percentage of packet loss (<1-100>)

Example configuration file

[nodes]
a:
b:
[links]
a:b delay=10ms bw=100

See ndn_utils/topologies for more sample files

Sample

Sample experiment may written as follows:

from mininet.log import setLogLevel, info

from minindn.minindn import Minindn
from minindn.util import MiniNDNCLI
from minindn.apps.appmanager import AppManager
from minindn.apps.nfd import Nfd
from minindn.apps.nlsr import Nlsr
from minindn.helpers.routing_helper import IPRoutingHelper

if __name__ == '__main__':
    setLogLevel('info')

    Minindn.cleanUp()
    Minindn.verifyDependencies()

    # Can pass a custom parser, custom topology, or any Mininet params here
    ndn = Minindn()

    ndn.start()

    # IP reachability if needed
    # IPRoutingHelper.calcAllRoutes(ndn.net)
    # info("IP routes configured, start ping\n")
    # ndn.net.pingAll()

    # Start apps with AppManager which registers a clean up function with ndn
    info('Starting NFD on nodes\n')
    nfds = AppManager(ndn, ndn.net.hosts, Nfd)
    info('Starting NLSR on nodes\n')
    nlsrs = AppManager(ndn, ndn.net.hosts, Nlsr)

    # or can not start NLSRs with some delay in between:
    # nlsrs = AppManager(ndn, ndn.net.hosts, Nlsr)
    # for host in ndn.net.hosts:
    #     nlsrs.startOnNode(host)
    #     time.sleep(30)

    MiniNDNCLI(ndn.net)

    # Calls the clean up functions registered via AppManager
    ndn.stop()

Users may look at how the NFD and NLSR applications are written as a sub class of Application in the minindn/apps folder. Or users may choose to directly run their application on nodes such as ndnpingserver is run in minindn/helpers/experiment.py.

Note: A certain log-level can be set-up for all the NFD or NLSR nodes at once by passing it as an argument during the startup.

nfds = AppManager(self.ndn, self.ndn.net.hosts, Nfd, logLevel='DEBUG') (same for NLSR)

Execution

To run Mini-NDN with the default topology, ndn_utils/topologies/default-topology.conf, type:

sudo python examples/minindn.py

To run Mini-NDN with a topology file, provide the filename as the first argument:

sudo python examples/minindn.py my-topology.conf

After Mini-NDN is installed, users can run examples from anywhere with python directly as follows:

sudo python /path/to/myexample.py

The user no longer needs to create an experiment in the old Mini-NDN way, then install it to the system before executing it via the minindn binary. The new examples can be separate from the Mini-NDN folder if the core is not being modified.

CLI Interface

During set up, the list of nodes in the network will be listed as they are initialized:

*** Adding hosts:
a b c d

After set up, the command-line interface (CLI) will display a prompt.

mini-ndn>

To interact with a node, first type the node’s name and then the command to be executed:

mini-ndn> a echo "Hello, world!"
Hello, world!

To see the status of the forwarder on the node:

mini-ndn> a nfdc status report

To see the status of routing on the node:

mini-ndn> a nlsrc status

To exit Mini-NDN, type quit in the CLI or use ctrl + D:

mini-ndn> quit

Ctrl + C is used to quit an application run in the foreground of the command line.

For a more in depth explanation of the CLI, please see the Mininet Walkthrough.

To run NDN commands from the outside the command line user can also open a new terminal and export the HOME folder of a node export HOME=/tmp/minindn/a && cd ~

Working Directory Structure

Currently Mini-NDN uses /tmp/minindn as the working directory if not specified otherwise by using the option –work-dir.

Each node is given a HOME directory under /tmp/minindn/<node-name> where <node-name> is the name of the node specified in the [nodes] section of the conf file.

NFD

  • NFD conf file is stored at /tmp/minindn/<node-name>/nfd.conf
  • NFD log file is stored at /tmp/minindn/<node-name>/log/nfd.log
  • .ndn folder is stored at /tmp/minindn/<node-name>/.ndn

NLSR

  • NLSR conf file is stored at /tmp/minindn/<node-name>/nlsr.conf
  • NLSR log file is stored at /tmp/minindn/<node-name>/log/nlsr.log

When security is enabled, NLSR security certificates are stored in: /tmp/minindn/<node-name>/security Note that no NLSR publishes the root certificate, Mini-NDN installs root.cert in security folder for each NLSR.

Routing Options

NDN Routing Helper

Computes link-state or hyperbolic route/s from a given minindn topology and installs them in the FIB. The major benefit of the routing helper is to eliminate the overhead of NLSR when using larger topology. See examples/static_routing_experiment.py on how to use the helper class.

IMPORTANT: NLSR and NDN Routing Helper are mutually exclusive, meaning you can only use one at a time, not both.

Note: The current version of ndn_routing_helper is still in the experimental phase. It doesn’t support node or link failure and runtime prefix advertisement/withdrawal. If you find any bug please report here or contact the authors.

IP Routing Helper

The routing helper allows to run IP-based evaluations with Mini-NDN. It configures static IP routes to all nodes, which means that all nodes can reach all other nodes in the network reachable, even when relaying is required. Please see examples/ip_rounting_experiment.py for a simple example.