FAQ

Contents

• What log level should you use when running emane?
• Does EMANE require virtualization?
• What operating systems does EMANE run on?
• Why would an event be attached to an OTA transmission?

What log level should you use when running emane?

Log output can have a significant impact on the fidelity of your emulation. It is recommended that you run all of the emane family of applications using log level 3. This will result in the output of all log messages INFO level and lower which will show you the current running configuration as well as any detected errors.

Does EMANE require virtualization?

EMANE does not require virtualization but that is not the right question to ask. EMANE can safely be thought of as being composed of two major subsystems. The first subsystem handles network emulation and the second handles routing traffic to and from the emulator. We refer to the second subsystem as the transport or application/emulation boundary. If you are using the Virtual Transport you need to provide network stack isolation for each NEM in your EMANE deployment. There are a number of ways to achieve this: use multiple physical computers, use virtualization or use LXC containers. So the proper question to ask yourself is how are you going to achieve network stack isolation?

What operating systems does EMANE run on?

EMANE runs on Linux.

Why would an event be attached to an OTA transmission?

EMANE 0.9 introduced attached events to the downstream packet API. DownstreamPacket::attachEvent() can be used to attach events to a packet for transmission across the OTA channel instead of the event channel.

Sometimes there is event information that originates from a radio model instance that must be synchronized across the emulation prior to the reception and processing of a packet. There is no way to guarantee this using two separate communication channels. When attached events are received as part of an OTA packet transmission, they are deserialized and pushed onto the message queue before the upstream packet is enqueued. This provides a guarantee that receiving NEMs will process the events prior to processing the received packet.

An example of this is the Antenna Profile control message and Antenna Profile event relationship. A radio model can send an Antenna Profile control message along with a downstream packet transmission. When this occurs, the emulator physical layer creates an Antenna Profile event and attaches it to the packet. All receivers will update the antenna profile information for the transmitter before processing the transmission.

If a radio model sends an Antenna Profile control message by itself, with no packet data, the physical layer will send out an Antenna Profile event using the event channel.

Attached events are for the exclusive use of radio models. It is considered extremely bad form for an event generator to send an event over the OTA channel.