Specifications

Defining Operating Parameters
5-21
• ELong - 1.076 seconds for line rates of 2.4 and 4.8 Kbps, 888 milliseconds for a
line rate of 9.6 Kbps (multiport framing disabled), and 640 milliseconds for line
rates of 9.6 (multiport framing enabled), 19.2, and 56 Kbps.
Notes: When this parameter is set to ELong, it is recommended that you set the
Automatic Poll parameter to disabled.
This parameter is used by the DAP only for internal processing of the alignment table. It
is not used for customer data.
If you know the network propagation delay, you can optimize this selection to the one
best suited for your network. Add the network propagation delay to the worst case
remote unit response time for the selected line rate as listed in Table 5-6. Select the
setting that is closest to but greater than the network propagation delay plus the worst
case remote unit response time value. For example, the correct setting for a unit running
at 4.8 Kbps with 34 µs propagation delay is: 432 ms (worst case remote unit response
time) + 34 µs (propagation delay) = 432.034 ms = Short.
Table 5-6. Remote Unit Response Time
Aggregate Rate
Worst Case Remote
Unit Response Time
2.4, 4.8 Kbps 432 ms
9.6 Kbps (multiport
framing disabled. 222 ms
9.6 (multiport framing
enabled), 19.2, 56 Kbps 117 ms
56 Kbps 134.5 ms
If any remote units are out-of-state, the recommended setting is Long. Otherwise, the
default setting, Med, should be suitable for most applications.
Automatic Poll
This parameter specifies whether the central unit automatically detects the presence of
any remote drops that have been added to or removed from the circuit. This parameter is
available only when the service is set for DDSNI, the Location parameter is set to central,
and the Network parameter is set to multipoint. The polling table can also be updated
manually using the Modify Drop Table feature described in the following section or it
can be updated by activating the Auto-Learn Network feature. (See Chapter 4, "Auto-
Learn Network" for instructions.) The disabled setting is recommended for networks
with infrequent topology changes.