Ethernet
6-22 Ethernet Workgroup Design
The Network Designer is looking for one or more per-port Ethernet switches that
can be used to make network connections to the stations in the CAD department.
The Network Designer examines the selection field of Ethernet switches, shown
in Table 6-2. All of these devices meet the initial criteria; they are manageable
Ethernet switches with similar expansion capabilities. Because of the Network
Designer’s intent to connect the Ethernet switches directly to the corporate FDDI
backbone, the products that do not support BRIM connections are eliminated
from consideration. This leaves the selection field shown below.
The Network Designer then moves on to examining the port count and media
type of the remaining devices. The NBR-620 is immediately removed from
consideration due to the low port count it provides. In order to meet the needs of
the network, the Network Designer would have to configure 6 NBR-620 Ethernet
switches, each of which would have to contain four EPIMs for 10BASE-T
connections and one BRIM for a connection to the FDDI backbone. As such a
solution would cost more than comparable solutions, without providing a
significant benefit over those solutions, the NBR-620 is removed from
consideration.
This leaves the selection field with the ESX-1320 and ESX-1380, two Ethernet
switches that support RMON management, one BRIM connection, and 12 switch
interfaces. The port count requirements are not met by either device alone,
however. The Network Designer refers back to the full selection field, looking for
a device that will support all 21 of the stations in the workgroup.
The device that is capable of supporting 24 switched Ethernet connections, the
FN10, has already been removed from consideration, but it is re-introduced due
to its higher port count. The Network Designer takes a second look at the
capabilities of the FN10 in comparison to those of the ESX-1320 and ESX-1380.
Deciding that the BRIM capability and advanced network management of the
ESX-1320 and ESX-1380 outweigh the higher port count of the FN10, the Network
Designer again removes it from consideration and continues.
The Network Designer than examines the media that are supported by the two
devices still under examination. The ESX-1380 supports 12 multimode fiber optic
connections, while the ESX-1320 supports unshielded twisted pair cabling.
Name Max
Management Media Port Count Switch
Interfaces PIMs/BRIMs
NBR-620 SNMP – 0 6 4 EPIMs
2 BRIMs
ESX-1320 RMON UTP 12 13 1 BRIM
ESX-1380 RMON Multimode
Fiber Optics 12 13 1 BRIM