Single Number Isdn Dial-Up; Channel And Modem Error Detection - Bay Networks 5399 Release Note

Single Number ISDN Dial-Up

The single number ISDN dial-up feature allows you to configure the unit
to discriminate automatically between the various protocols that may be
used for dial-up over ISDN. This allows you to lower operating costs by
purchasing a single dial-in number to cover all remote access needs, rather
than having separate numbers for TA (V.120 and V.110), synchronous
PPP, and modem users. The design of this method great flexibility to
determine how to handle calls because it does not require any particular
disposition of a call solely based on the protocol in use. Instead, the
session parameter block (SPB) mechanism is used to determine how to
handle the call after the protocol has been detected, and a set of carefully
chosen defaults allows simple configuration.
X.75 connections require a separate number, since X.75 is not
autodetecting in this release.

Channel and Modem Error Detection

The RAC detects call errors by comparing counts of different events in
the progress of calls coming in through channels (for CAS only) and
modems. The error counts are kept separately because modems are
assigned to channels dynamically, and are not mapped directly.
Mismatches between the event counts for a call on a channel or modem
indicate errors in the call. A call fails if it does not reach DCD assertion,
or, in the case of a non-modem call, if it is not assigned to a device
successfully. Failed calls for each channel or modem are counted as well,
and when the count of consecutive failures reaches a specified threshold
value, three events occur: a syslog message is sent, an SNMP trap is sent,
and the corresponding channel or modem is taken out of service (busied-
out). The intent of this is to notify a network administrator who can
examine and correct the problem.
Remote Access Software Version 5.3 Release Notes
300115-B Rev. A
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