Black Box 5000 series Reference Manual page 87

Menus Reference Manual: Edit Remote Site - Connection Set-Up - ISDN Call -Advanced Settings Menu
Auto-Call Considerations:
When two ISDN numbers are defined in the ISDN Call Set-Up menu of the remote site entry, the router will
alternate between the two numbers when re-dialing.
When the router attempts to establish an Auto-Call ISDN call and the PPP router at the remote site does not
respond, the router will try up to the number of times defined in the Redial Count to establish the ISDN call. The
interval between the successive attempts is defined by the Redial Timer. If after the defined number of redials the
router cannot establish a call to the remote partner, the router will wait for one minute and then try to establish
the ISDN call again using the Redial Count and the Redial Timer values. If the call is not established after these
attempts, the router will wait for 2 minutes and then try again. The router will keep trying to establish the call
(according to Redial Count & Redial Time) in blocks with the time intervals: 4 minutes, 8 minutes, 15 minutes, 15
minutes, etc.) until the remote partner answers the call.
When the ISDN switch type is set to KDD or NTT, the minimum time between re-dialing blocks is 3 minutes.
When the Redial Count is set to zero (0), the router will redial the remote partner indefinitely at one minute
intervals using the defined ISDN numbers for the remote site according to the redial blocks explained earlier. The
router will alternate between the two defined ISDN numbers for the partner in blocks of #1, #2 with a time
between the two ISDN numbers of 4 seconds.
Address Connect Considerations:
When the router attempts to establish an Address Connect ISDN call and the remote partner does not respond,
the router will not attempt to redial the remote partner until the next Address Connect connection is required.
If two ISDN numbers are defined in the ISDN Call Set-Up menu of the remote site entry, the router will dial the
alternate ISDN number after waiting 4 seconds if the first ISDN number does not respond.
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