14.7.5.3. Set IP-Address for OpenScape 4000 to trusted in case of Digest
Authentication 
Common Management Portal > OpenScape Voice > Administration
> Signaling Management > Digest Authentication > Realms >
Add
Activate the Trusted Entity checkbox and enter the IP address
for Signaling Primary (e.g: 10.237.191.31 (HG 35xx of OpenScape
4000))
OpenScape Voice: Set IP address for OpenScape 4000
to trusted