I have two sites A(central) & B(Branch Office), spread across two different countries by WAN.
Site a has a CCM5.1 cluster(One PUB & One sub) and Site B has one SRST GW.
When WAN is up site B uses local SRST Gw as voice GW for PSTN dial-in/dial-out but site A CCM's for call processing.
How can site B used local site PRI lines for call in/out to PSTN if the WAN is up but the local site SRST GW HW fails(Voice GW Fails).i.e. how to get redundancy for Voice GW/PSTN calling if the WAN is up but local GW fails.