Black Box 12-Port 1000BASE-TX L2 Managed PoE Switch User Manual page 21

12-Port 1000BASE-TX L2 Managed PoE Switch with 2 SFP Dual Media Ports
1000BASE-X TP , Fiber
Round-Trip Delay: 4096
Cat. 5 TP Wire: 11.12/m
Fiber Cable: 10.10/m
Bit Time Unit: 1 ns
(1 sec./1000 Mega bit)
The sum of all elements' bit-time delay and the overall bit-time delay of wires/devices must be within the
bit-time (round-trip) delay in a half-duplex network segment (collision domain). For full-duplex operation, this
will not apply. Use the TP-Fiber module to extend the TP node distance over fiber optic cable and to provide
the long-haul connection.
Typical Network Topology in Deployment
A hierarchical network with minimum switch levels may reduce the timing delay between the server and the
client station. This approach will minimize the number of switches in any one path. It will also lower the
network loop possibility and will improve network efficiency. If more than two switches are connected in the
same network, select one switch as the Level 1 switch and connect all other switches to it at Level 2. We
recommend that you connect a server/host to the Level 1 switch.
Example 1: Same LAN.
All switch ports are in the same local area network. Every port can access each other (see Figure 3-3).
12-Port 1000BASE-TX L2
Managed PoE Switch with 2
SFP Dual Media Ports
18
Table 3-1. Cable's bit-time (round-trip) delay.
1000BASE-TX TP
Cat. 5 TP Wire: 1.12/m
TP to Fiber Converter: 56 kbps
Bit Time Unit: 0.01 ms (1 sec./100 Mega bit)
PCs
Figure 3-3. No VLAN configuration.
100BASE-FX Fiber
Round-Trip Delay: 512
Fiber Cable: 1.0/m
12-Port 1000BASE-TX L2
Managed PoE Switch with 2
PCs
SFP Dual Media Ports
Server/host