Verilink PRISM 3030 (34-00208.L) Product Manual - Manual (Page 103)

Ground Start DNIS with Delay 93
Ground Start
DNIS with Delay In Ground Start DNIS operation, an FXS application module in GS-DNIS mode is
connected to the CPE equipment. Another FXS application module in DPO mode
is connected to the CO and supplies loop current to the CO. The DNIS service is
inbound only (from the CO to the CPE). Outbound calls are handled as
MEGACOM or MEGACOM with Reverse Battery.
Idle
State
The FXS application module opens tip and provides
−
48V to ring towards the
CPE. The FXS transmits A and B signalling bits = 0 towards the CO, receives an
A bit = 0, and ignores the B bit.
Call
Originated
from CO
When the CO seizes the line, the FXS receives an A bit = 1 and ignores the B bit.
The FXS application module provides ground to tip, then delays for 90
milliseconds. Then the FXS transmits A and B signalling bits = 1 towards the CO
and generates a ring signal to the CPE with a cadence of 2 seconds ringing and 4
seconds non-ringing until the CO terminates the call or the CPE answers.
CPE Answer The CPE answers the ring by looping tip to ring.
Digit
Transmit
After the CPE answers, the FXS transmits A and B signalling bits = 0 towards the
CO. The CO then passes digits to the CPE as DTMF tones. The digit transmit time
can be set from 1 to 5 seconds.
Connect While connected, the FXS transmits A and B signalling bits = 1 towards the CO,
receives an A bit = 1, and ignores the B bit.
CPE
Terminate
The CPE terminates the call by opening the loop from tip to ring. The FXS
transmits A and B signalling bits = 0 towards the CO. The FXS opens tip.
CO
Terminate
The CO terminates the call by transmitting the A signalling bit = 0 for 500
milliseconds or greater. After the 500 ms, the FXS transmits A and B signalling
bits = 0 towards the CO and opens tip.