Grass Valley MRC v.1.2 - Manual (Page 151)

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Miranda Router Configurator
User’s Guide
Devices that reside on the same subnet may communicate with each other. For devices to
communicate on a network, they must reside on the same subnet.
The subnet is determined by a subnet mask.
What is a Subnet Mask?
The subnet mask is a 32-bit mask that determines how many bits of an IP address are used for
the subnet and how many bits are used for device identifiers.
Generally, the left-most 24 bits are used for the subnet and the right-most 8 bits are used for a
device identifier. Thus, the typical subnet mask is represented by 255.255.255.0. (The value 255
is the decimal value of eight “1” bits.)
A subnet mask does not need to be 24 bits. A mask of 22 bits (255.255.252.0) allows 4 times as
many devices on the subnet. Most NVISION equipment defaults to 24-bit subnet masks.
What is a Gateway IP Address?
A gateway is a network router that allows two subnets to communicate. A gateway IP address
identifies the gateway, allowing a device to communicate with the other subnet.
Cabling
Use Category 5 Ethernet cable for all Ethernet connections. (Ethernet connectors are RJ-45.)
Some router connections (particularly for automation) require serial cables. These connectors
are DE-9, female.)
Using Switches
When several devices must be interconnected, a network switch is required. Switches transmit
data from any one port to all other ports, and receive data from any port. All Miranda products
support communication at 100
Mb/s. When you are selecting a switch, make sure it works at this
speed. It will need one port for every device you intend to connect.
Note: when you are connecting only two devices (for example, the configuration PC and a single
router control card), you can use an Ethernet crossover cable between the PC and the control
card. A switch is not required.
Routing
Routing is the connection of (output) signals from one device to the input(s) of another device
through another device (the router) under software control. The term device represents a broad
range: cameras, video recorders, satellite feeds, monitors, meters, up/down converters, distribu-
tion amplifiers, and so on.
The term device, in the context of NV9000-SE Utilities, is defined as a set of related router
inputs and outputs, possibly spanning multiple routers of different types. The inputs and
outputs in the set are usually connected to a single physical device.
It is possible, and sometimes desirable, to define multiple devices that use the same ports.
You might do this to be able to treat audio input or output as stereo at times and as mono at
other times.