3Com CoreBuilder 3500, Руководство по внедрению, Страница: 78 / 592

78 C
HAPTER
5: E
THERNET
Key Guidelines for
Implementation
Consider these important factors when you implement and configure
Ethernet networks.
Link Bandwidths Recommended link capacities in a network normally depend on the
speed requirements of end-user workstations, as shown in Table 5. In
areas that may benefit from 1000 Mbps pipelines, you may be able to
substitute trunked Fast Ethernet, subject to the issues raised in Chapter 8.
Trunks Consider these important factors when you implement and trunk Fast
Ethernet or Gigabit Ethernet links:
■
3Com recommends that you use trunks to increase network
availability in the following circumstances:
■
Switch-to-switch connections in the data center and campus
interconnect areas
■
Switch-to-server connections in the data center and campus
interconnect areas
■
Downlinks from the data center to the campus interconnect area
■
When multiple links are trunked, it can be difficult to manage and
troubleshoot individual port-to-port connections if a connectivity
problem occurs. This issue may not be of concern in a server farm
room. But if you use trunking extensively between wiring closets and
data centers, the large number of connections involved and their
distributed nature may make their management and troubleshooting
difficult.
When you work with trunks, be sure that you understand the port
numbering for your system. For port-numbering information on the
CoreBuilder 3500, see Chapter 4. For more information about trunking,
see Chapter 8.
Table 5 Recommendations for Structuring Bandwidth Across the LAN
Desktops to
Wiring Closet Wiring Closet to
Data Center Data Center to
Campus Interconnect
Mainstream
networks Switched 10 or
Shared 10/100 Switched 100 Switched 1000
Power
networks Switched 10/100 Switched 1000 Switched 1000+