Zhone Technologies IMACS Network Device - Manual (Page 41)

Zhone Technologies, Inc. IMACS Product Book, Version 4
March 2001 Page 37
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
Nortel CO Switch
Line 1
IMACS with
PPO Line Card
Network
IMACS with
PPS Line Card
P-Phone #1
:
:
:
:
:
:
:
:
P-Phone #N
T1
E1
T1
E1
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.