NT5K21 XMFC/MFE card Page 359 of 894

MFC signaling involves two or more levels of forward signals and two or more levels of backward signals. Separate sets of frequencies are used for forward and backward signals:

Forward signals. Level I forward signals are dialed address digits that identify the called party. Subsequent levels of forward signals describe the category (Class of Service) of the calling party, and may include the calling party status and identity.

Backward signals. Level I backward signals (designated “A”) respond to Level I forward signals. Subsequent levels of backward signals (B, C, and so on) describe the status of the called party.

Table 136 lists the frequency values used for forward and backward signals.

Table 136

MFC Frequency values (Part 1 of 2)

 

Forward direction

backward direction

Digit

DOD-Tx, DID-Rx

DOD-Rx, DID-Tx

 

 

 

1

1380 Hz + 1500 Hz

1140 Hz + 1020 Hz

2

1380 Hz + 1620 Hz

1140 Hz + 900 Hz

3

1500 Hz + 1620 Hz

1020 Hz + 900 Hz

4

1380 Hz + 1740 Hz

1140 Hz + 780 Hz

5

1500 Hz + 1740 Hz

1020 Hz + 780 Hz

6

1620 Hz + 1740 Hz

900 Hz + 780 Hz

7

1380 Hz + 1860 Hz

1140 Hz + 660 Hz

8

1500 Hz + 1860 Hz

1020 Hz + 660 Hz

9

1620 Hz + 1860 Hz

900 Hz + 660 Hz

10

1740 Hz + 1860 Hz

780 Hz + 660 Hz

11

1380 Hz + 1980 Hz

1140 Hz + 540 Hz

12

1500 Hz + 1980 Hz

1020 Hz + 540 Hz

13

1620 Hz + 1980 Hz

900 Hz + 540 Hz

 

 

 

Circuit Card Description and Installation

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Nortel Networks 553-3001-211 manual NT5K21 XMFC/MFE card Page 359