8.11.2.2.4. Silent monitoring 
- The key MONSLNTL uses the BUZZ destination and request the witness (destination) to enter. The witness enters the conversation, after the entry request, by pressing the line button or lifting the handset. The third party does not get any signaling about this and the witness can only listened in. For using the Buzz-function, only one witness can be defined per subscriber.
- The "witness" must be in the same OpenScape 4000 and must be a member of a keyset.
- The solution for the add-on witness connection is a combination of the already existing Buzz and bridge features.
- No network wide function.
Changing key layout (extend STD 126 and 127)
CHANGE-TAPRO:STD=126,DIGTYP=OPTIT19,KY18=MONSLNTL; CHANGE-TAPRO:STNO=7210&7211,STD=126;
Add BUZZ destinations
ADD-ZIEL:TYPE=BUZZ,SRCNO=7210,DESTNOBZ=7211; ADD-ZIEL:TYPE=BUZZ,SRCNO=7211,DESTNOBZ=7210;
The audible line must exist at both QLRUFNU and BUZRUFNU. Both must also belong to
one keyset
and be configured on one system. Add additional authorization.
Add additional authorization
CHANGE-SDAT:STNO=7210,TYPE=ATTRIBUT,AATTR=MONSLNTL; CHANGE-SDAT:STNO=7211,TYPE=ATTRIBUT,AATTR=MONSLNTL;
Key layout after generating this step
