Basic WAN Information:

• Have two core sites (Different Location)

            Data Centre

            Disaster Recovery

• Data Centre WAN Equipments

            2 CISCO3845-HSEC/K9 with 6 FE WAN interface

• Disaster Recovery WAN Equipments

            1 CISCO3845-HSEC/K9 6 FE WAN interface

• Branch WAN Equipments

            1 CISCO1941-SEC/K9 2 FE WAN interface

• Remote Site

            400+ Branches

• service providers (Layer 2 Data Connectivity)

            4 Service Providers connect with DC & DR

            2 Service Providers connect with each branch

• Bandwidth

            DC & DR Site Connect on demand for each Service Provider

            Branch Site Connect 64 Kbps for each Service Provider

See topology.jpg

Traffic Flow Requirements:

As Data Centre side has two Hub Routers, so we want the traffic flow

• Load      balancing in context of Service provider
• Active-Standby      in context of Data Centre Core Routers

Communication need only to DC & DR Routers. No need to communication among branches

See traffic-flow.jpg

We may have some site-to-site vpn solution available

• Standard      IPSec VPN
• GRE      over IPSec VPN
• DMVPN
  

I want to use DMVPN and chose OSPF as IGP.

Is there anyone who can help me by giving suggestion for the Optimal and scalable solution for my network by considering the WAN resources?

Thanks