FAQ
=========

* ``How does Mini-NDN work?``

Mini-NDN's principles of operation most heavily rely on the underlying Mininet code it relies on.
Mininet uses a combination of limited containerization via network namespaces (which give processes
isolated interfaces and routing tables) and emulated ethernet connections via veth connections.
In practical terms, Mini-NDN ensures that processes running on distinct nodes will run seperately
and without interfering with each other.

* ``How does Mini-NDN apply link loss/delay/etc.?``

Mini-NDN relies on Mininet's code, which in turn uses the Linux tc utility on a stations' virtualized
interfaces to apply configurations known as qdiscs to these links. Note that these will only be applied
on egress packets from a station where it's applied.
For more information on qdiscs and tc, view the information `here <http://wiki.linuxwall.info/doku.php/en%3aressources%3adossiers%3anetworking%3atraffic_control>`_.

* ``Why use Mini-NDN rather than a simulator such as ndnSIM?``

Mini-NDN is easier and faster to use because, rather than serving as a mathematical model of a network,
it is instead running real NDN code on a real Linux kernel. This also means it's quite useful for testing code changes, as it can more accurately test the interaction of software componenents.

+--------------------------------+-----------------------------------------------------------+-----------------------------------------+
| Criteria                       | Mini-NDN                                                  | ndnSIM                                  |
+--------------------------------+-----------------------------------------------------------+-----------------------------------------+
| Based On                       | Mininet                                                   | ns-3                                    |
+--------------------------------+-----------------------------------------------------------+-----------------------------------------+
| Language                       | Python                                                    | C++                                     |
+--------------------------------+-----------------------------------------------------------+-----------------------------------------+
| Library/Forwarder/Applications | Use system binaries (free to use any compatible versions) | Integrated (fixed release version)      |
+--------------------------------+-----------------------------------------------------------+-----------------------------------------+
| Application language           | C++ (ndn-cxx), CCL (ndn-cpp, PyNDN, ndn-js, jNDN)         | C++ (ndn-cxx)                           |
+--------------------------------+-----------------------------------------------------------+-----------------------------------------+
| Simulation size                | Medium - Large (cluster edition in development)           | Large (can be parallelized using MPI)   |
+--------------------------------+-----------------------------------------------------------+-----------------------------------------+
| Simulation time                | Real time                                                 | Quick (depending on size/memory)        |
+--------------------------------+-----------------------------------------------------------+-----------------------------------------+
| Porting real applications      | Drop in                                                   | Changes required                        |
+--------------------------------+-----------------------------------------------------------+-----------------------------------------+
| Interactivity                  | Can interact directly with NFD, NLSR or Apps              | Can show stats while running            |
+--------------------------------+-----------------------------------------------------------+-----------------------------------------+
| Logs                           | May need to manually setup to collect                     | Available with tracer                   |
+--------------------------------+-----------------------------------------------------------+-----------------------------------------+
| Post processing scripts        | Not available, users need to write their own              | Available to use to process the logs    |
+--------------------------------+-----------------------------------------------------------+-----------------------------------------+
| Other                          | Not yet supported (Wifi in development)                   | WiFi, LTE, etc available from ns-3      |
+--------------------------------+-----------------------------------------------------------+-----------------------------------------+