Verilink DIU 2130 (880-503297-001) Product Manual - Manual (Page 88)

DIU/DIM Details
7-8 Verilink
Carrier
Requirements
Contact the T1 line provider (telco) and verify that the network will
support the B8ZS encoding scheme.
Clear-channel operation and data equipment rates
When using a DIU 2130, the requirement for a clear-channel T1 line
depends upon the data equipment transmission that will be used.
The following guidelines apply:
1. If you have selected a data rate of 56 kbit/s or a multiple of 56
kbit/s, the DIU 2130 can operate at any data rate up to and
including 1.344 Mbit/s without a clear-channel T1 line.
2. If you have selected a data rate that is a multiple of 64 kbit/s,
the following guidelines apply:
• If you assign alternate DS0 channels (i.e., odd-numbered or
even-numbered channels only), the DIU 2130 can operate
at any data rate up to and including 768 kbit/s. This mode
is used when B8ZS is not available.
• If you assign DS0 channels randomly such that two
channels in a frame are never next to each other (i.e., 1, 4,
6, and 9), then a clear-channel T1 line is not required.
• If you assign DS0 channels such that two channels in a
frame are next to each other (i.e., 1, 2, 6, and 7), then a
clear-channel T1 line is required.
• If you assign DS0 channels contiguously (in numeric
sequence), a clear-channel T1 line is required at all data
rates at 128 kbit/s and above. Include 64 kbit/s if the
adjacent channels are also used for 64 kbit/s or if rates
higher than 64 kbit/s are required by the application.
• Simply put, for rates = n × 64, B8ZS is required.
Drop and Insert
Mode
If you are connected to a DS1 channel bank using 64 kbit/s data
and configured for drop and insert, all of the guidelines apply.
DIU Interface Operation
The CSU of the NCC or TAC can operate with DIU 2130s for high-
speed customer data transmission over the T1 network. The CSU
provides this data service in either a T1 multiplexer mode or a
drop-and-insert mode.
T1 Mux Mode Figure 7-12 shows how the CSU of an SCC, NCC, or TAC interfaces
with one or more DIUs in a T1 multiplexer mode. In the transmit
direction toward the network, each DIU multiplexes the incoming
data from the customer data equipment. It places the data in the