Example network topologies
FortiGate WAN optimization consists of a number of techniques that you can apply to improve the efficiency of communication across your WAN. These techniques include protocol optimization, byte caching, web caching, SSL offloading, and secure tunneling. Protocol optimization can improve the efficiency of traffic that uses the CIFS, FTP, HTTP, or MAPI protocol, as well as general TCP traffic. Byte caching caches files and other data on FortiGate units to reduce the amount of data transmitted across the WAN. Web caching stores web pages on FortiGate units to reduce latency and delays between the WAN and web servers. SSL offloading offloads SSL decryption and encryption from web servers onto FortiGate SSL acceleration hardware. Secure tunneling secures traffic as it crosses the WAN.
You can apply different combinations of these WAN optimization techniques to a single traffic stream depending on the traffic type. For example, you can apply byte caching and secure tunneling to any TCP traffic. For HTTP and HTTPS traffic, you can also apply protocol optimization and web caching.
You can configure a FortiGate unit to be an explicit web proxy server for both IPv4 and IPv6 traffic and an explicit FTP proxy server. Users on your internal network can browse the Internet through the explicit web proxy server or connect to FTP servers through the explicit FTP proxy server. You can also configure these proxies to protect access to web or FTP servers behind the FortiGate unit using a reverse proxy configuration.
Web caching can be applied to any HTTP or HTTPS traffic, this includes normal traffic accepted by a security policy, explicit web proxy traffic, and WAN optimization traffic.
You can also configure a FortiGate unit to operate as a Web Cache Communication Protocol (WCCP) client or server. WCCP provides the ability to offload web caching to one or more redundant web caching servers.
FortiGate units can also apply security profiles to traffic as part of a WAN optimization, explicit web proxy, explicit FTP proxy, web cache and WCCP configuration. Security policies that include any of these options can also include settings to apply all forms of security profiles supported by your FortiGate unit.
Basic WAN optimization topology
The basic FortiGate WAN optimization topology consists of two FortiGate units operating as WAN optimization peers intercepting and optimizing traffic crossing the WAN between the private networks.
Security device and WAN optimization topology
FortiGate units can be deployed as security devices that protect private networks connected to the WAN and also perform WAN optimization. In this configuration, the FortiGate units are configured as typical security devices for the private networks and are also configured for WAN optimization. The WAN optimization configuration intercepts traffic to be optimized as it passes through the FortiGate unit and uses a WAN optimization tunnel with another FortiGate unit to optimize the traffic that crosses the WAN.
You can also deploy WAN optimization on single-purpose FortiGate units that only perform WAN optimization. In the out of path WAN optimization topology shown below, FortiGate units are located on the WAN outside of the private networks. You can also install the WAN optimization FortiGate units behind the security devices on the private networks.
The WAN optimization configuration is the same for FortiGate units deployed as security devices and for single- purpose WAN optimization FortiGate units. The only differences would result from the different network topologies.