Cisco Cisco Expressway
Appendix 3: Extended Microsoft
Deployments
Deployments
Clustered Gateway
When this document refers to a Gateway Expressway, a cluster of Expressways can also be used. The operation is
functionally the same, but there is more capacity available.
functionally the same, but there is more capacity available.
Calls from Microsoft FE will typically arrive at a single Expressway in the cluster because the Microsoft infrastructure
uses a static route; the route resolves to a single FQDN for TLS connectivity, or to a single IP address for TCP
connectivity.
uses a static route; the route resolves to a single FQDN for TLS connectivity, or to a single IP address for TCP
connectivity.
If you use a DNS A record to to map the peers' addresses to the FQDN of the cluster, the DNS server typically returns
the addresses in a different order each time the FE Server queries DNS (round-robin). The FE server chooses one of
the returned addresses, based on its own logic (outside of this document's scope).
the addresses in a different order each time the FE Server queries DNS (round-robin). The FE server chooses one of
the returned addresses, based on its own logic (outside of this document's scope).
Microsoft Environments
Microsoft environments have a number of building blocks, and so they may be constructed in many ways. A full scale
Microsoft deployment is likely to use Director, Hardware Load Balancers (HLBs), Front End Servers in enterprise
pools, and a redundant AD server.
Microsoft deployment is likely to use Director, Hardware Load Balancers (HLBs), Front End Servers in enterprise
pools, and a redundant AD server.
Microsoft recommend that DNS may be used in place of hardware load balancing for routing SIP traffic. Microsoft
guidance can be found at
guidance can be found at
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Cisco Expressway with Microsoft Infrastructure Deployment Guide
Appendix 3: Extended Microsoft Deployments