Black Box KV1700A/E, User Manual

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SERVSWITCH™ OCTET INSTALLER/USER GUIDE
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non-Black Box KVM switch. To use seamless cascading, you will need to configure the
cascaded target device as Multiple Device Mode (MDM).
Blocking and non-blocking configurations
Before setting up a cascaded Octet switching system, evaluate how many users and how
many target devices are needed in your system. You can then choose how to best
configure your system: as a blocking or a non-blocking configuration, or a combination.
Whether the configuration is blocking or non-blocking is determined by how user paths
are connected in the switching system. In a cascaded system, UTP cable is connected from
the server ports on the primary switch to the user ports on the secondary switches. To add
a tertiary level of switches, UTP cable is connected from the server ports on secondary
switches to the user ports on the tertiary switches (see Figure 3-11 on page 40 for an
example). Each length of UTP cable acts as a path to connect users to target devices.
Blocking and non-blocking configurations are defined as follows:
• Non-blocking configuration – the number of user paths between each level of
switches is equal to or greater than the number of users the primary switch supports.
The maximum number of user paths are available and thus any user (with the
appropriate access rights) can access any target device in the switching system at any
time.
• Blocking configuration – the number of user paths between each level of switches is
less than the number of users the top level switch supports. A limited number of user
paths are available in this configuration, which at times might prevent or block a user
from accessing a target device. However, you may be able to attach more target
devices to the switching system when using a blocking configuration.
Figure 3-10 illustrates one possible blocking configuration in an Octet switching system.
In this example, a four-user Octet switch is cascaded off of an eight-user Octet switch. The
target devices attached to the primary switch will never be blocked and can be accessed at
any time. The secondary switch has only four user paths attached to it, creating a blocking
configuration. When connections are made to four of the target devices on the secondary
switch, there are no more user paths available for that switch. The other users in the
system can share access to the connected target devices, but they cannot connect to any
other target device on that switch. Once a user closes a connection to a target device, that
user path is open and can be used to connect to any target device in the switching system.