Nortel Enterprise 1000 Reference Manual

Also see for 1000 Con?guration guide: Brochure Reference User manual Overview User guide

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Nortel Enterprise 1000 Reference Manual Manual pdf 54 page image

Page 54 of 236 Analog Trunk Cards - NT8D14 Universal Trunk Card553-3023-211 Standard 1.00 June 2001Outgoing callsFor outgoing calls, the software sends an outgoing seizure message to placea low-resistance loop across the tip and ring leads toward the CO. SeeFigure 13 on page 55 and Figure 14 on page 56. When the CO detects thelow-resistance loop, it prepares to receive digits.When the CO is ready toreceive digits, it returns a dial tone. Outward address signaling is then appliedfrom the Succession CSE 1000 in the form of loop (interrupting) dial pulsesor DTMF tones.Polarity-sensitive/-insensitive packs featureThe Succession CSE 1000 software provides the polarity-sensitive/polarity-insensitive (PSP and PIP) packs feature for the accurate recording of outgoingcall duration for loop start and ground start operation. On trunks equippedwith far-end answer supervision, the PSP class of service is enabled insoftware and causes call-duration recording in CDR records to begin onlyupon receipt of answer supervision from the far-end. For trunks not equippedwith answer supervision, the PIP class of service is enabled and call-durationrecording begins immediately upon near-end trunk seizure. The PSP and PIPclasses of service are enabled in the Trunk Administration programLD 14.Ground start operationGround start operation is configured in software and implemented throughsoftware download messages. In the idle state, the tip conductor from the COis open and a high-resistance negative battery is present on the ring lead.Incoming callsIn an incoming call, after ground is detected on the tip, the universal trunkcard scans for a ringing detection signal before presenting the call to anattendant and tripping the ringing. When the attendant answers, a lowresistance is placed across the tip and ring conductors, which trips CO ringingand establishes a speech path. See Figure 13 on page 55 and Figure 14 onpage 56.Reverse-wiring compensationThe Succession CSE 1000 software includes a feature for detecting reverse-wiring (connection of the near-end tip and ring leads to the far-end ring andtip leads) on ground start trunks with far-end answer supervision.