[K12OSN] designing a new school's network

[Sam Snow]

I read the following article this weekend and was reminded of the recent 
discussion on network designs for a school that would be terminal server 
friendly. The article talked about an alternative to the traditional 
network design that they claim offers both more bandwidth to the user and 
a lower cost. I've included a link and quick excerpt that talks about the 
bandwidth advantages of this design.

Sam


"Bringing increased bandwidth ever closer to the user"
A new architecture known as fiber-to the-telecom enclosure capitalizes on 
the bandwidth capabilities of optical circuits. 
http://cim.pennnet.com/display_article/281158/27/ARTCL/none/none/Bringing-increased-bandwidth-ever-closer-to-the-user/

A small excerpt:
"High performance is an additional key benefit of FTTE. Both the low- and 
high-density FTTE options provide excellent performance in terms of 
bandwidth delivered to the work area. In many enterprises, 32-port 
switches are typically deployed and configured with one 1-Gbit/sec fiber 
uplink to the ER. This provides each workstation approximately 31 
Mbits/sec of average throughput (1 Gbit/sec divided by 32 ports). Even if 
the 32-port switch is configured with two 1-Gbit/sec fiber uplinks, the 
average throughput available to each workstation is only 63 Mbits/sec.

In each of these cases, the backbone has insufficient capacity to carry 
the full traffic from all workstations, each running at their maximum rate 
of 100 Mbits/sec. This design results in an .oversubscribed. switch (32 
ports x 100 Mbits/sec = 3.2 Gbits/sec required, where only 1 or 2 
Gbits/sec is available).


The FTTE low-density design offers the highest performance to the work 
area because the 8-port mini-switch is totally non-blocking. That is, 
excess .capacity. exists as 200 Mbits/sec remains on the 1-Gbit/sec fiber 
backbone to the TR when all eight ports are operating at 100 Mbits/sec. 
The switch is able to provide connectivity to all eight workstations 
requiring 100 Mbits/sec simultaneously, because the aggregate total from 
the eight workstations is 800 Mbits/sec and the uplink can provide 1,000 
Mbits/sec. The mini-switch in the FTTE low-density design is 
.non-blocking. or .undersubscribed.. The high-density FTTE design 
represents a sacrifice in performance, but offers increased installation 
savings."