Specifications

Chapter 6: Programming
Configuring a Single-Port/Dual-Port T1/E1/PRI Module (T1M/T1M-2)
Page 6-130 Mitel
®
5000 Installation Manual – Issue 3.0, October 2008
CRC Processing
(Applies only to E1/PRI equipped modules.) The CRC Processing flag is a configuration flag
that can be enabled/disabled for each E1 module. The setting for this flag must match the
setting for the remote-end E1 signal. When CRC Processing is enabled only at one end of an
E1 connection, the E1 signal with the CRC enabled will never reach the CRC Multiframe
synchronization state and will transmit the RAI signal to the remote end until either the CRC
Processing is disabled for that E1 signal or the CRC Processing is enabled for the remote-end
E1 signal.
This flag enables the transmission of a CRC Multiframe pattern and a CRC-4 value computed/
transmitted for every 16 frames of data. At the same time, the CRC Processing flag enables the
E1 module to look for this CRC Multiframe pattern and CRC-4 value on the received E1 signal.
When CRC Processing is enabled on both ends of an E1 connection, both ends will reach the
CRC Multiframe synchronization. In this multiframe synchronized state, both ends will compute
a CRC-4 value and transmit it to the other end along with the E1 data. On the receive ends of
the E1 connection, both receivers will then calculate their own CRC-4 value for the received
data and if the received and the computed CRC-4 values match, the corresponding 16 frames
of E1 data are assumed to be have been received with no bit errors.
Haul Mode
This field applies only for a T1 or T1/PRI configuration (E1/PRIs do not display this field). Short-
haul implies a shorter span and the corresponding loop length field lists lengths for the cable.
Long-haul implies a longer cable with the need for a repeater and the line build out field lists its
associated signal strengths. In previous versions, only Long Haul was available for the T1 or
T1/PRI. It is set to Long Haul by default.
To change the setting:
1. Select the current Value, then use the drop-down list box to scroll to the desired setting.
2. Press ENTER or click another field to save the change.
Line Build-Out
(Applies only to T1 and T1/PRI modules.) The LBO attenuation of the T1 trunk connected to the
module value is determined by the distance to the nearest public network T1 repeater. The
selections are shown below.
• 0 dB (DSX-1)
• –7.5 dB (this is the best setting for T1/E1/PRI modules)
• –15 dB
• –22.5 dB
The Auto option should be used during initial installation. The other settings can be used if the
build-out needs to be adjusted later.
To change the setting:
1. Select the current Value, and then use the drop-down list box to scroll to the desired
setting.
2. Press ENTER or click another field to save the change.