PRG Mbox Designer Manual 3.9 - Manual (Page 176)

168 MBOX ® MEDIA SERVER USER MANUAL
MBOX NETWORKING GUIDELINES
Concepts
The majority of communications to and from Mbox use Ethernet protocols. This means Ethernet networks route the
data into the Mbox server and from the server to other connected devices. Because all of these protocols need to live
in harmony, steps need to be taken to avoid interference between protocols, and to maximize the available network
bandwidth/speed. Due to these requirements, it is recommended that the computer used as an Mbox server have
more than one network interface. For more complex setups, three or four network interfaces are preferable.
While all the network interfaces on a computer could be connected to the same network to gain some amount of
additional bandwidth, doing so would bypass the desire to keep certain protocols separate. Therefore, it is far more
useful if each network interface on the computer is configured for and connected to a separate physical Ethernet
network - or, if connected to the same physical network, then with a system of VLANs enabled to segregate different
protocols.
Connecting more than one network interface to different networks is only the first step. Each interface needs to have
its IP Address and subnet mask set correctly for the network that it is being connected to. Getting the IP Address and
subnet mask correct ensures that communications to and from the computer will use the correct interface and arrive
at the intended destination without any ambiguity or loss of data.
Concept definitions:
+ Network Interface - the physical Ethernet connection (typically RJ-45) on the computer that may be used to
connect the computer to a physical network.
+ Network - a group of devices physically connected to each other that can potentially communicate using Ethernet
IP protocols. The word "network" describes not just the physical connection of multiple devices, but also the
"web" of electronic communication between them.
+ Subnet (subnetwork) - a logical subdivision of a network such that multiple interfaces can be connected to the
same physical network, but are placed on different subdivisions of that network for the purposes of routing or for
keeping some communications separate. (Note: a subnet is not the same as a VLAN.)
+ IP Address - an interface property using the dot-decimal (e.g., 2.0.0.123) notation, where each of the four
numbers separated by decimal points is referred to as an octet (because each is an 8-bit number). In combination
with the interface’s subnet mask, the octets in the IP address designate either the device's sub-network or the
device's unique identifier on that subnet.
+ Subnet Mask - a second interface property, also using dot-decimal notation (e.g., 255.0.0.0). The value of each
octet in the subnet mask determines which of the octets in the device's IP address specify the sub-network and
which specify the interface’s unique identifier on that sub-network. The subnet is specified by setting one or
more of the octets to a value other than 0.
Subnet Masking Basics
For pretty much all communication to and from Mbox, each octet in an interface's subnet mask will be set to either 0
or 255. Values other than 0 or 255 can be used for more complicated subnetting, but are typically not needed with
Mbox and won't be discussed here.
In order to understand how an interface's subnet mask works, you need to look at it together with the interface's IP
address. If an octet in the subnet has a value of 255, then the corresponding octet in the interface's IP address is used
to designate the subnet that the interface belongs to. If an octet in the subnet mask has a value of 0, the
corresponding octet in the IP address is used as part of the interface's unique identifier on that subnet. Within the
structure of sub-networks and unique identifiers, it is possible to have multiple interfaces on the same subnet, each
being uniquely identifiable. Data can be sent to all interfaces in the subnet by broadcasting, to groups by multicasting,
or to individual members by unicasting.