Nortel Enterprise 1000 Reference Manual page 104

Page 104 of 236
553-3023-211 Standard 1.00 June 2001
NT8D15 E&M Trunk Card
Trunk unit functions
The functions provided by each unit on the E&M trunk card include 2-wire
signaling, 4-wire signaling, and paging operation as follows:
• 2-wire, E&M Type I signaling (see Figure 36 on page 105) with:
— near-end seizure and outpulsing with M lead
— ground detection with E lead
— voice transmission through tip and ring for transmit and receive
• 4-wire, E&M Type I and II signaling, 2-way dial repeating with:
— echo suppression for Type I signaling
— switchable 7 dB and 16 dB pads for carrier interface
— voice transmission and reception through two separate paths
— Type I signaling through E&M leads
— Type II signaling with near-end seizure by SB/M leads and far-end
detection by E/SG leads
• 4-wire, DX signaling (see Figure 37)
• paging trunk operation (see Figure 38) with:
— support access by low-resistance path at the PG/A1 leads
— paging end-to-end signaling not supported