3Com Switch 7700 Configuration Manual page 313

By default, RADIUS request packet will be retransmitted up to three times.
Enabling the Selection of the RADIUS Accounting Option
If no RADIUS server is available or if RADIUS accounting server fails when the
accounting optional is configured, the user can still use the network resource,
otherwise, the user will be disconnected.
Perform the following configurations in RADIUS server group view.
Table 24 Enable the Selection of the RADIUS Accounting Option
Operation
Enable the selection of the RADIUS accounting
option
Disable the selection of the RADIUS
accounting option
The user configured with accounting optional command in RADIUS scheme longer
sends a real-time accounting update packet or offline accounting packet.
The accounting optional command in a RADIUS server group view is only
effective on the accounting that uses this RADIUS server group.
By default, selection of RADIUS accounting option is disabled.
Setting a Real-time Accounting Interval
To implement this feature, it is necessary to set a real-time accounting interval.
After the attribute is set, NAS will transmit the accounting information of online
users to the RADIUS server regularly.
Perform the following configurations in RADIUS server group view.
Table 25 Set a Real-Time Accounting Interval
Operation
Set a real-time accounting interval
Restore the default value of the interval
The minute variable specifies the real-time accounting interval in minutes. The
value must be a multiple of 3.
The value of minute is related to the performance of NAS and RADIUS server. The
smaller the value is, the higher the performances of NAS and RADIUS have to be.
When there are a large amount of users (more than 1000, inclusive), we suggest a
larger value. The following table recommends the ratio of minute value to the
number of users.
Table 26 Recommended Ratio of Minute to Number of Users
Number of users
1 to 99
100 to 499
500 to 999
1000
By default, minute is set to 12 minutes.
Configuring the AAA and RADIUS Protocols
Command
accounting optional
undo accounting optional
Command
timer realtime-accounting minute
undo timer realtime-accounting
Real-time accounting interval (minute)
3
6
12
15
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