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When outbound packets from the enterprise network pass through the firewall, it translates the
source IP address to the outside IP address of the firewall system.
A static and direct 1:1 NAT mapping is recommended for the outside firewall.
● The inside firewall, which resides between the RealPresence Access Director system in the DMZ and
the LAN (Trust), must be in Route mode.
In this mode, the firewall does not change the destination or source IP address, so no translation
is required or supported.
For details on how to configure the network interfaces, see DMZ Deployment with One or More Network
Interfaces.
Deployment in a DMZ environment takes advantage of the firewall’s security functionality. However,
because all media and signaling traffic flows through the firewall, performance can be affected.
A RealPresence Access Director system that uses at least two network interfaces can be deployed in a
“two-legged” configuration. In this scenario, signaling and media traffic are split between the interfaces to
separate external and internal traffic.
Integration with an F5 Load Balancer
Two or more RealPresence Access Director systems can be deployed behind an F5 Networks load balancer
to increase network capacity (concurrent users) and improve overall performance by decreasing the burden
on any one RealPresence Access Director system.
The F5 load balancer acts upon data in the transport layer and serves as a TCP or UDP reverse proxy to
distribute (balance) incoming sign-in, registration, and call requests across multiple RealPresence Access
Director systems. When the F5 load balancer receives a request, it distributes that request to a particular
RealPresence Access Director system according to the Round Robin algorithm. An F5 load balancer can
help to ensure RealPresence Access Director system reliability and availability by sending requests only to
systems that can respond in a timely manner.
The configuration of the F5 load balancer’s routing policy must support persistence. Persistence ensures
that all requests from the same source IP address during a session are distributed to the same
RealPresence Access Director system. A heartbeat connection between the F5 load balancer and all
RealPresence Access Director systems ensures that requests are routed only to an accessible system.
The F5 load balancer must be configured to integrate with your RealPresence Access Director systems, but
no configuration is necessary on the RealPresence Access Director systems. See Integrate Two or More
Systems with an F5 Load Balancer.
Deployment in a Two-System Tunnel Configuration
Two RealPresence Access Director systems can be deployed in a tunnel configuration (see The
RealPresence Access Director System Two-System Tunnel Deployment). In this model, one system acts
as the tunnel server and is deployed in the corporate back-to-back DMZ. The other system serves as a
tunnel client and is deployed behind the inside firewall. Communication between the tunnel server and the
tunnel client is through UDP transmission.
In a tunnel configuration, port mapping on the inside firewall between the tunnel server and the tunnel client
is not required. Instead, when you enable the tunnel feature on the tunnel server, the tunnel port is open
and listening for communication from the tunnel client. When you enable the tunnel feature on the tunnel
client, the client then registers to the tunnel server through the listening tunnel port.