Nortel Networks BCM50 - Manual (Page 46)

46 Chapter 2 Introducing the BCM50 hardware
NN40020-302
• Firmware downloading capability: The core can upgrade the ASM8+ and GASM firmware at
customer sites.
• Enhanced ringing capability: ASM8+ and GASM provide a ringing voltage of 2 REN/65 V
rms per port.
• The GASM8 is designated as an ONS (on-premise station) port.
• Disconnect supervision (Open Switch Interval (OSI) as per EIA/TIA 464): indicates to the
attached device, in an established communication, that the connected device releases the call.
The ASM8, ASM8+, and GASM each has one RJ-21 connector on the faceplate. The figure
GASM faceplate LEDs and connectors on page 46 shows the GASM.
Figure 17 GASM faceplate LEDs and connectors
The ringer equivalency number (REN) (per port) for ASM8 is 1; the REN for ASM8+ and GASM
is 2.
Disconnect supervision note: When disconnect happens from the Central Office
(CO), the ASM8+ provides an open switch interval (OSI) to the off-hook station of
850 milliseconds (ms) (TIA/EIA 464 section 5.4.10.2.4, minimum is 600 ms) as a
disconnect signal. If the station remains on-hook after the disconnect signal, the
ASM8+ disconnects the station equipment from the network without returning a
tone (TIA/EIA 464 section 5.4.10.2.5[1]). After the station equipment goes
on-hook, the ASM8+ station interface is restored to on-hook (idle).
You must ensure the device, application, or interface card connected to an ASM8+
station interface conforms to these on-hook and off-hook conditions.
Note: The termination of the analog interface can consist of any combination of devices,
subject only to the requirement that the sum of the RENs of all the devices does not exceed
the REN of the interface to which the device is connected.