MERLIN LEGENDCommunications System Release 6.1 | Issue 1 |
System Planning 555-661-112 | August 1998 |
3 Lines/Trunks | |
| Selecting Line/Trunk Options | Page 3-12 |
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| Loop-Start Reliable Disconnect | 3 |
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Disconnect signals on incoming calls on loop-start trunks are classified as one of the following:
■Reliable. A disconnect signal is sent to the system by the local telephone company shortly after a caller hangs up. Loop-start trunks must be reliable for remote call forwarding and trunk-to-trunk transfer. Also, reliable disconnect is strongly recommended for remote call transfers, and VMSs such as MERLIN LEGEND Mail.
NOTE:
If the local telephone company uses a short hold disconnect interval, do not specify a reliable disconnect signal. Also, to ensure proper voice messaging operation, and for private network systems, the system must have ground-start or loop-start trunks with reliable disconnect.
■Unreliable. A disconnect signal is not sent by the local telephone company on every call.
!SecurityAlert:
Toll fraud can occur when loop-start lines/trunks are used with unreliable disconnect. If the calling party stays on the line after the called party hangs up, the central office will return a dial tone at the conclusion of the call enabling the caller to place another call as if it were being placed from your company.
Since the disconnect signal on most loop-start trunks is unreliable, the factory setting for the disconnect signal is Unreliable.
Before you change the setting, check with the telephone company to determine whether the disconnect signals for the loop-start trunks are reliable and to obtain the length of the hold disconnect interval.
If you select Reliable disconnect, you can set the interval after which the line/trunk is released as described in “Hold Disconnect Interval” later in this section.
Trunk-to-trunk transfer is programmed on a per-extension basis and should remain disabled even if the loop-start trunk has reliable disconnect. See the “Trunk-to-Trunk Transfer” section in Chapter 4.
Planning Form Instructions
At the top of Form 2c, under the Loop-Start Reliable Disconnect heading, choose one of the following:
■If the loop-start trunks have an unreliable disconnect signal, check the No box (the factory setting).
■If the loop-start trunks have a reliable disconnect signal, check Yes.
