IBM OPTIONS ATM OC-3c, User Manual

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4-2 C
HAPTER
4: P
UTTING
Y
OUR
ATM N
ETWORK
T
OGETHER
■
Does your network meet safety specifications?
You should always follow safety requirements and
ensure that your device environment meets all
technical specifications.
For the ATM Module these requirements are specified
in Appendix A. For other devices, refer to the user
guides that accompany those devices.
■
Does your network conform to the ATM
configuration rules?
Make sure that your network meets the configuration
rules described in “ATM Configuration Rules”.
ATM Configuration Rules
There are several things that you should consider
before configuring your network:
■
Your cables and equipment must meet all of
the technical specifications.
The ATM cable you connect to the ATM Module,
must conform to the Multi-Mode Fiber (MMF-PMD)
standard defined by ANSI x.3-166-1992.
3Com supports 62.5/125mm multi-mode fiber
(MMF-PMD) cable. The maximum inter-station
distance (including device-to-network connectors)
should not exceed 2km (1.25 miles).
■
Allow for attenuation (weakening of signal)
when calculating cable lengths.
■
Ensure that you have sufficient bandwidth.
Refer to Appendix C, “ATM Module Technical
Specifications” for more details.
You cannot connect an IBM 8271 Nways Ethernet
LAN Switch ATM OC-3c Module to another IBM 8271
Nways Ethernet LAN Switch ATM OC-3c Module; this
is due to the signalling requirements used by ATM
and LANE. There must be a standards-based ATM
Switch between the two modules for them to operate
correctly.
Extending VLANs Through the ATM Network
When setting up VLANs and extending them into the
ATM network you should consider the following:
■
What logical network domains, VLANs, do
you wish to set up?
Traffic from one
Emulated LAN (ELAN)
will not be
seen on another ELAN (unless a router is used), as
they are logically separate domains. For this reason
you should consider:
■
What ELANs you require.
■
How the VLANs will map to the ELANs.
■
If you need to route between any of your ELANs.
■
Will you have sufficient ELAN resources?
When calculating the resources you require, you
should consider the number of:
■
ELANs that your LAN Emulation services can
support.
■
VLANs/ELANs that each edge-device can support.