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Zhone Technologies, Inc. | IMACS Product Book, Version 4 |
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P-Phone Station and Office Line Cards
The P-Phone Line Cards support transport of Nortel Electronic Business Service (EBS) or P-Phone service. Nortel’s EBS is provided through the use of an Electronic Business Set (also EBS) capable of supporting premium Meridian Digital Centrex (MDC) features offered by the local DMS SuperNode switch. A data channel allows out-of-band signaling between the EBS and the DMS SuperNode switch. This data channel allows the user to activate MDC features, such as conference calling, by simply pushing special keys on the EBS, and for the DMS SuperNode to deliver information, such as calling number identification, to the EBS display.
P-Phone is a very popular service among large corporations who have chosen Nortel Centrex vs. a PBX. This service is very popular in metropolitan areas; as more companies move away from purchasing their own PBXs, P- Phone will be even more popular among the corporate DMS customers. In addition, as more and more CLECs enter traditional RBOC bases, they will need to be able to provide P-Phone services.
Figure 10A shows a general application drawing where an IMACS system is used at both the CO end and at the customer remote end. As shown, there are two applications of the Line Card, one at the office end, also known as P- Phone Office (PPO), and one at the station end referred to as P-Phone Station (PPS).
Figure 10 - Universal IMACS P-Phone Application | | | |
| | | P-Phone #1 |
| | | : |
Line 1 | | | : |
Network | T1 | : |
T1 | E1 | : |
| : |
E1 | | |
| | : |
IMACS with | | IMACS with | : |
| PPS Line Card | : |
PPO Line Card | | | P-Phone #N |
Nortel CO Switch | | | |
Two types of P-Phone line cards are used in pair gain carrier systems such as DLCs and the IMACS system. One type, referred to as a passive line card, encodes the received out-of-band signaling tones, transports them across the carrier and decodes the digital representation back to out-of-band tones at the other end. In other words, the passive line card simply repeats the signaling end-to-end. The second type, referred to as an active line card, terminates the messages received at the 2-wire port and either responds as appropriate to the local terminal device or forwards the message over the digital carrier.
The above figure shows just one working circuit. In reality, the Line Card will be able to support eight (8) working circuits. The most common application for P-Phone would have more than one circuit going to a customer location. Very rarely would there be just one circuit terminating at one customer. The P-Phone line cards support the following Nortel PBXs, switches and Meridian business phone sets:
•DMS100 (Class 5 switch)
•DMS500 (Combinations of Class 5 and a tandem switch)
•DMS10 (Lower capacity switch for rural areas)
•SL100 (Large enterprise PBX; same as DMS100)
•M5000 series business sets
Table 12A reviews the PPO and PPS line card specifications.
