Frequently Asked Questions
Networking Setup in an EEG Alta VM
What is the default network configuration for a new Alta VM?
Usually you will need to explicitly enable one or more physical adapters to be assigned to the Alta VM in your VM hypervisor software (such as VirtualBox, VSphere, etc.). Most of these systems have several options for how the network ports will behave – for example in VirtualBox, “Bridged Adapter” puts the guest VM directly on the network the host is on, while “NAT” puts the guest VM on an internal network to its host, where it will not be directly accessible from outside the host. Please consult the documentation on your hypervisor if you have questions.
All interfaces in the Alta guest VM will initially be configured for DHCP.
How can I set static IP addresses on the Alta guest VM?
To set a static IP address, start the Alta VM, log into its desktop, and go to “Applications Menu” > “Settings” > “Network Connections”. Choose the appropriate NIC (which physical connections come up is determined through the VirtualBox menu described in the previous step – if there is any question about which NIC is which go to “Ethernet” > “Device MAC Address” and match these values up to the ones in the VirtualBox menu), and go to “IPv4 Settings”. Change from “Automatic (DHCP)” to “Manual” if needed, and then add the desired IP address, netmask, gateway, and DNS servers as appropriate. For this work, the IP address and subnet have to be appropriate for the network that is being reached through the physical adapter that is reached through the VirtualBox settings for this virtual NIC.
Linux command line tools such as the “ip” command may also be used inside the Alta VM. Check the appropriate man pages or reference guides.
How many networks can Alta connect to simultaneously? How can multiple networks be used?
There is no specific limit set by EEG on how many networks an Alta VM can be connected to. You may be restricted by the number of physical networking ports on your host machine, or by the number supported by your virtualization software per VM.
It is possible to run all Alta-related functions (receive & transmit of media streams, web-based management, outbound connections to iCap/Lexi, and licensing validation) through a single network interface (NIC). It is also possible to divide these functions for reasons including increased bandwidth for media streams, QoS, and security separation of outbound iCap traffic and media networks.
The Alta VM will have a separate IP address for each separate network it is connected to.
The network for outbound iCap traffic should usually go through eth0 or the “first” network adapter if possible. This will prevent you from having to re-configure a different adapter as the “default route” for outbound traffic out of your local subnets.
For multicast media streams, use the “Multicast Interface” setting on each stream to set the IP address that for media transmit/receive.
For unicast media stream reception, provide the IP address of the interface to receive the stream on in the “input” field of the Alta channel. If only a port number is provided, unicast streams will be received across all interfaces on that port (and you must not send multiple unicast streams on the same port, even to different interfaces). For unicast stream transmission, the lowest numbered interface with a subnet matching the destination will be used (unless a different default route is set up in the Alta underlying Linux system).