Determining Network Connectivity Strategies

ATM Design Considerations

ATM networks are made up of three distinct components: endpoint elements (users), ATM switches, and interfaces. Consider the guidelines discussed in the following sections when you design an ATM network.

Use the Default ELAN

Windows 2000 ATM is initially configured with a default unspecified ELAN name. If you plan to implement a small LAN emulation, it is recommended that you use the preconfigured default unspecified ELAN. If you are implementing a large ATM network, multiple ELANs are more manageable and secure.

When purchasing an ATM switch, it is recommended that you check the product specifications to ensure that it is preconfigured with an ELAN that uses the default unspecified ELAN name. Switches that are preconfigured with a default ELAN allow for a more trouble-free setup in a small ATM environment.

Use Supported ATM Adapters

Before you buy an ATM adapter for use with Windows 2000, be certain that it is on the Windows 2000 Hardware Compatibility List. For more information, see the Hardware Compatibility List link on the Web resources page at http://windows.microsoft.com/windows2000/reskit/webresources.

Note Configurations Before You Upgrade

Before upgrading from Windows NT 4.0 to Windows 2000, note the following configuration information for each of the LAN emulation clients you plan to upgrade:

The ELAN name
The media type to be emulated on the LAN
ATM addresses for the LAN Emulation Server (LES) and Broadcast and Unknown Server (BUS) associated with the ELAN

Configure the ELANs

After you note these configuration parameters, use the configuration interface on your ATM switch to configure the LAN Emulation Configuration Service (LECS), the LAN Emulation Service (LES), and the Broadcast and Unknown Service (BUS) to support the ELANs and their associated parameters. Next, install Windows 2000 and configure the ELAN name for each LEC.

Use Only One ATM ARP/MARS for Each Logical IP Subnet

If your network uses IP/ATM, it is recommended that you configure only one ATM ARP/MARS for each logical IP subnet on your network. If you have multiple ARP servers on the same network segment, and your ARP client is configured with the addresses for these servers, the ARP caches could become out of sync. This can render parts of the network unreachable.