I'm integrating a CM5.1(2) cluster to a Siemens iSDX network via Westell converters (IiQ2000+) to enable Q.Sig to DPNSS interoperability.
We have the following topology:
CM Cluster <-> IP Network <-> 2811 ISR <-> Q.Sig <-> Westell <-> DPNSS <-> iSDX.
There are two links like this in parallel. We have set up the Westells using the "wizard" configuration procedure.
We need to get each system to automaticlly re-route calls via the other path on failure of ANY component in the path.
We have one problem where we currently cannot re-route:
If the LAN connection on the 2811 is unplugged, the MGCP link goes down, but the 2811 maintains the Q.Sig link at layer 2, causing the Westell to maintain the DPNSS link. The Siemens thus sees this as an available path and will send calls this way, which cause the Westell to respond with CRM 02 message (Network Termination). The Siemens cannot re-route on this condition.
What I think I need is a way for the Q.Sig trunk to be busied-out when the backhauled link fails.
Has anyone got any ideas on how this can be achieved?
I have had suggestions that using MGCP fallback will allow me to take the router into SRST mode if the LAN fails, so is it then possible to get the trunk busied-out when this happens? Theoretically this would allow a correct signal to be sent back to the Westell and thence through to the Siemens, which could re-route on busy.