High Availability:Software:Signaling Stack:ISDN
From TBwiki
High Availability
Live Reconfiguration
With Toolpack, it is possible to add/modify/remove any ISDN stacks without needing to stop the whole system.
Redundancy
The ISDN protocol doesn't have an innate high availability feature. The only way to increase the reliability of a system using ISDN is to mix the stacks between the provider and the Tmedia hardware, when available.
Here is an example: