Figure 4–15 shows an extension of the Secure Remote Access basic configuration. Multiple Gateway instances run on the same machine or multiple machines. You can start multiple Gateway instances with different profiles.
Although Figure 4–15 shows a 1-to-1 correspondence between the Gateway and the Portal Servers, this need not necessarily be the case in a real deployment. You can have multiple Gateway instances, and multiple Portal Server instances, and any Gateway can contact any Portal Server depending on the configuration.
The disadvantage to this configuration is that multiple ports need to be opened in the second firewall for each connection request. This could cause potential security problems.