Deployment Modes of Citrix SD WAN

Citrix SD-WAN offers flexible options for deployment depending on use cases, or high availability requirements in the primary Data Center, Branch, or Cloud Resource locations.

Hardware appliances can be deployed seamlessly in the path between the LAN and the WAN edge network. If the device goes offline for any reason the physical Ethernet connection, through the equipment between switches or routers, remains intact.

Virtual Inline
An approach that offers similar usage to Inline, without the need to physically interrupt the primary data center network. The Citrix SD-WAN equipment is implemented on a VLAN adjacent to the Edge router which uses policy routing to direct pertinent traffic to it for optimization.

Edge / Gateway Mode
Takes over responsibility for WAN edge networking including terminating leased lines, routing, firewall, and internet proxy filtering in addition to providing full SD-WAN functionality. This mode allows enterprises to consolidate branch hardware to maximize network throughput, availability, and security while minimizing complexity and cost.

Hardware platforms include fail-to-wire (Ethernet bypass) cards for direct in-path deployment. If power fails, a relay closes, and the input and output ports become electrically connected, allowing the Ethernet single to passthrough from one port to the other, defaulting to the existing underlay network.

Find more: SD-WAN vs. MPLS

The various deployment options (Inline, Virtual Inline, Edge) support high-availability. A pair of devices can be deployed at a site location in Active/Standby roles. This high availability deployment operates similar to Virtual Router Redundancy Protocol (VRRP), ensuring the SD-WAN Overlay is continuously active.

Geographically Distributed MCN
A secondary data center or branch site can be assigned the role of Secondary MCN (also known as GEO MCN). This site takes the responsibility of the primary data center SD-WAN and ensure that the SD-WAN Overlay continues to operate until the primary site comes back online.