Initial
Configuration:
Building A West
will initially be configured to run at 100 Mbps via Gigabit capable fiber with
10/100 media converters on each end. It will be connected to the MDF at the
Cisco 2948-GL3 in an Ethernet port running at 100 Mbps. It will connect in the
IDF side at the Cisco 2980G-A in an Ethernet port also running at 100 Mbps. The
two 2980G-As will cascade to each other via 10/100 Ethernet ports running at
100 Mbps.
All PCs will run
initially at 10 Mbps. (Bear in mind that the servers are in the MDF and will be
directly connected to the Cisco 2948-GL3 in that closet at 100 Mbps.) All
circuits will terminate in a lockable cabinet which will contain one 8-port hub
per circuit. All circuits will be Category 6 certified using an Agilent
Wirescope 350 test unit.
The data
terminations at the remote ends will be configured utilizing dual RJ45 data
jack modules. As the faceplate can hold as many as three dual data modules,
most terminations will consist of a faceplate, 2 dual data modules and 1 blank
filler plate, allowing for another data module to be added later, if necessary.
Some of the administrative offices only require a single data outlet. For these
locations, dual data modules will still be used, with one side of the modules
not being cabled. As vendors change their termination packaging, this will
ensure that if another cable has to be added, the addition can be done without
the need to re-terminate the existing user’s circuit onto new hardware and thereby
avoid downtime for that user.
To Upgrade the
Network Configuration:
To increase the
speed of the PCs and the backbone is a simple matter. The PCs can be
reconfigured for 100 Mbps because the cabling is Category 6. (True, this can be
done with Cat 5e, but at a later point in time, this cabling scheme will
support Gigabit Ethernet over the same copper/terminating hardware with no
additional expense incurred.)
To increase the
backbone speed, remove the Ethernet connection between the two switches. Next, install
two 2 GBICs in the primary 2980G-A and one in the cascaded 2980G-A. This will
allow the 2980G-As to communicate with each other at Gigabit speed using one
GBIC in each. The second GBIC in the primary 2980G-A will replace the media
converter connecting to the MDF. Once a GBIC has been installed in the
2948-GL3, the backbone connection can be reconfigured to run at Gigabit
Ethernet speed. As the GBICs are included in the Parts list, this involves no
additional expense.
Intent:
Yes, the TCS
required Cat 5, which is less expensive (and already obsolete). However, I have
been involved in installing cabling infrastructures for 15 years and in that
time I have dealt with Categories 3, 4 (briefly), 5 and 5e (4 in 15 years).
Each time a new technology has evolved, a major investment has had to be made
to replace the cabling, closet and remote terminating hardware. The TCS calls
for a 10-year life span for the infrastructure. Although using Category 6 components is approximately 1/3 more
costly, it is the only way I can foresee this installation having a 10 year
life span.