There is a new Service Parameter in my 5.1(2) UCM called
Clusterwide Parameters (Feature - Join Across Lines And Single Button Barge Feature Set)
Enable Single Button Barge and Join Across Lines:
System wide configuration of Single-Button Barge, CBarge feature .
Maximum length: 20
: In order for the change to take effect on a cluster-wide basis, you must either restart all affected Call Managers, reset all affected Device Pools, or restart/reset all affected phones.
I can't find any documentation on it other than what is says here. Does anyone have any experience with this or have you tried it yet?
Thanks in advance