Zhone IMACS 8000, User Manual

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Reference Guide 4-9
Applications Data Modules and Applications
Software-initiated diagnostics support include the setting of local loop backs towards either
the network or the attached DTE equipment. Additionally, a remote loop back function allows
the HSU card to generate three DDS-compatible latching loop back codes for the far-end
OCU, CSU and DSU equipment. Similarly, the HSU data port may be programmed to detect
and respond to both latching and non-latching DDS-format OCU, CSU and DSU loop back
codes initiated from the remote end of the circuit. A time-out option authorizes the HSU port
to automatically release the loop back after ten minutes. This feature applies to an HSU port
that is running at 56 Kbps or for super-rate circuits if the loop back code is transmitted in the
first super-rate’s DSO. The card can also generate and recognize two industry standard
in-band loop-up and loop-down codes that act on the entire super-rate circuit. Those are the
ITU (CCITT) V.54 code and the ANSI Fractional T1 code.
Additionally, the integral Bit Error Rate Tester (BERT) can be used to generate test patterns
and route those towards the WAN facility. These test patterns can then be used to verify
synchronization and measure circuit quality. For further information regarding Performance
Monitoring and Diagnostic Capabilities, see Chapter 8, System Testing and Diagnostics.
Applications
There are several applications the Integrated Access System equipped with an HSU card
supports.
• LAN to LAN
• LAN to WAN to LAN
• Work Station to Computer
• Computer to Computer
• Teleprotection circuits
• CSU/DSU interfaces
• Microwave radio interface
4.3.2 HSU Application Example
A major Health Maintenance Organization has numerous locations which have a Central main
hospital facility and smaller satellite facilities. The HMO cannot afford to fully staff each main
and satellite site with specialist. As patients enter the satellite facilities, video and audio
sessions can be established with the specialists at the Main hospital. Although the satellite
sites are not equipped with Intensive Care Units, emergencies can be admitted and support
solicited from the Main hospital personnel as shown in Figure 4-4.