[xtam1]

Dear All,

Kindly I have the following questions regarding the below setup,

VoIP GW1---Backup PRI[to PBX using PSTN]
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Leased Line
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VoIP GW2
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PRI
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PBX----Backup PRI[from VoIP GW1 via PSTN]


1- Let's say that the Leased line between GW1 & GW2 fails so the calls will flow via the backup PRI.
2- If the VoIP GW2 fails so it's going to be the same as in the previous case.

# My question is:
What if the PRI link between VoIP GW2 & the PBX fails or what if the PBX itself failed.. How will the VoIP GW1 detect this case and switch to the backup PRI?!!

The diagram will be the same if the PRI Link between the VoIP GW2 & PBX Fails, but in case of PBX failure actually the diagram will be as
follow:

VoIP GW1
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Backup PRI[to BackupPBX using PSTN]
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Backup PBX


VoIP GW1 is Cisco 2650XM Router
VoIP GW2 is Cisco 3745 Router

How will the VoIP GW1 detect this case and switch to the backup PRI to dial the backup PBX?!!

Regards,
Tamer Bayomy