Zhone 891630, Справочное руководство системы

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Reference Guide IMACS System Release 5.1.9 2-13
Applications Data Modules and Applications
An OCU-DP port on the 8249 card may be programmed for OCU mode or CSU mode. OCU
mode is the most common and is used whenever the OCU-DP port attaches to a CSU/DSU
over a four-wire circuit. CSU mode allows the card to be connected directly to the digital
network.
Software initiated diagnostics supported by the OCU-DP card include the setting of six
different loop backs. Three of these act on the OCU-DP card itself and are known as local loop
backs and the other three generate loop back patterns to remote devices and are known as
remote loop backs. Among local loop backs, there are three types:
• loop backs of the 4-wire analog interface of the OCU-DP port towards the attached CSU
• loop backs of the 4-wire OCU-DP interface towards the network
• loop backs towards the network at the point where the OCU-DP card interfaces with the
system bus
All three remote loop backs are latching loop backs. These latching loop backs are:
• loop back of the analog interface of the remote OCU-DP device back towards the
network
• loop back of the 4-wire interface of the remote CSU device back towards the network
• loop backs of the 4-wire interface of the local CSU device towards the network.
An OCU-DP port may be programmed to detect and respond to both latching and non-latching
(i.e., alternating) DDS-format OCU loop back codes that are initiated from the remote end of
the circuit. A time-out option authorizes the OCU-DP port to automatically release the loop
back after ten minutes.
2.3.5 BRI Card (826X Series)
The 826x line of BRI Cards offers industry standard ISDN BRI “U” or “S/T” Interfaces. Each
BRI Card supports eight BRI “U” Interfaces for long line circuit provisioning, or “S/T”
Interface for local provisioning. The BRI Interface provides two bearer and one data channel
over two wires (1 pair). The S/T interface provides the same functionality over 4 wires (2
pair). In addition to this, each BRI “U” Interface supports 256x NTUs, providing remote NTU
management.
The Basic Rate Interface “U” Interface card offers connectivity to sites located up to 18,000
feet from the Integrated Access System. This distance is influenced by factors such as wire
gauge, bridge tap and loading patterns as described in ANSI T1.601-1992 specifications. The
BRI cards are equipped with eight “U” interfaces that can carry one BRI, 2B+D channel. This
will give users either two 64 Kbps or one 128 Kbps bearer channels per interface. The “U”
Interface is also provides optional sealing current for maintaining wire pair performance.