3Com CoreBuilder 9000, Руководство пользователя

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Network -to- Network Interface (NNI) 329
ILMI Connectivity
Polling
The CoreBuilder 9000 ATM Enterprise Switch polling facility continuously
verifies the connectivity of the ILMI channel of a port. It determines that
the adjacent IME has failed when it does not receive a response for 120
consecutive retry polling requests.
After the polling facility determines that the ILMI connection has
failed—a period of about 10 minutes—the ILMI restarts its operation on
that port after clearing all previous information including registered
addresses.
The polling interval is normally 30 seconds. You can enable or disable the
polling facility by management and you can set the polling interval. (For
more information, see “Display ILMI Channel Polling Status” on page 128
and the commands that follow.) Shortening the polling interval increases
the speed of detection of an Change Of Attachment Point event. (For
more information, see “Gateway Interface (GWY)” on page 331.)
Parameters Polled
Each time that the IME polls its peer IME, it requests the current values of
the variable Network Management IP Address — atmfMyIpNmAddress.
(When the Change of Attachment Point mechanism is enabled, a
different set of variables is polled; see “Gateway Interface (GWY)” on
page 331.)
Network -to-
Network Interface
(NNI)
The Network-to-Network Interface (NNI) is a protocol that interconnects
two ATM switches in a network. The NNI provides the same interface
management features as does the UNI. In addition, it provides an ability
to determine the best route through the network to a given destination.
It provides the following:
Switch-to-Switch interface management
Database of network connections
Method for routing over the NNI interfaces
Ability to route over various network topology configurations, for
example, star, mesh, or tree