Verilink PRISM 4101 (34-00230) Product Manual - Manual (Page 49)

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Timing. The unit can source its timing from three choices. NET uses the network
recovered clock (the normal DDS mode). DTE uses the clock recovered from the
DTE port and is allowed only when the Data Mode is set to Standard. INT uses the
internal oscillator (25 ppm) for all timing.
Circuit Assurance. Allows the CTS control lead to respond to the data signal from
the network.
If On is selected, the unit will turn Off the CTS lead when receiving idle code (for
example, if DCD is Off). If Off is selected, the state of the CTS control lead is not
affected by data signal from the network.
When Circuit Assurance is set to Off, CTS follows RTS. When RTS transitions to
the On state, CTS will transition to the On state after the RTS/CTS delay. CTS will
transition to the Off state within one bit time when RTS transitions to the Off state.
When Circuit Assurance is set to On, CTS follows RTS if DCD is On. When RTS
transitions to the On state, CTS will transition to the On state after the RTS/CTS
delay if DCD is On. CTS will transition to the Off state when RTS transitions to
the Off state. CTS is Off if DCD is Off.
RTS should be set to Normal on the DTE PORT parameters when Circuit
Assurance is On. The Force DCD option will be changed to Normal.
Antistreaming Timer. The Antistreaming Timer is used to prevent a streaming DTE
on a tributary DSU, in a multi-point circuit, from locking up the circuit. It is
controlled by RTS. If RTS remains enabled long enough for a timeout to occur, the
unit will drop CTS and stop sending DTE data. The Antistreaming Timer is reset
when RTS transitions to the Off state. Choices are Off, 10, 30, and 60 seconds.
DTE Port Parameters
When operating in the proprietary mode, an end-to-end management link is
established between units. Remote communications between units operates on a
sideband channel and is not disruptive to the customer’s data traffic. On a 56 K
loop, the maximum DTE rate is 54 K sync (57.6K async) and on a 64K loop, the
maximum DTE rate is 62K. At line rates less than 56 kbps, only async format is