Flow cache based mechanism of packet redirection in multiple border routers for application awareness

An apparatus, comprising:

• a network interface unit configured to communicate over a LAN interface, a WAN interface, and a tunnel interface of a first border router;
• a processor coupled to the network interface unit;
• and
• a memory having instructions stored thereon, wherein execution of the instructions, cause the processor to:
• maintain, in a flow cache, for a first application flow associated with one or more first packets received at the LAN interface, wherein the flow cache at the first border router comprises one or more attribute values to identify whether the first border router is a LAN-side border router or a WAN-side border router with respect to the first application flow;
• in response to receipt of a second packet at the WAN interface, determine whether the received second packet is associated with an existing application flow in the flow cache;
• set a second attribute flag in the flow cache when the second packet is received at the WAN interface, wherein the second attribute flag identifies whether the apparatus is a WAN-side border router;
• in response to determining that the received second packet is associated with the first application flow in the flow cache, send the received second packet to a LAN-destination device associated with the LAN interface;
• and
• in response to determining that the received second packet is not associated with an existing application flow in the flow cache, forward the received second packet to a second border router over the tunnel interface, wherein the second border router is configured to send the second packet to the LAN-destination device upon a determination that the received second packet comprises, in a second flow cache maintained at the second border router, an association with the first application flow.

One or more non-transitory computer readable storage media encoded with software comprising computer executable instructions and when the software is executed operable to:

• maintain, in a flow cache, for a first application flow associated with one or more first packets received at the LAN interface, wherein the flow cache at the first border router comprises one or more attribute values to identify whether the first border router is a LAN-side border router or a WAN-side border router with respect to the first application flow;
• in response to receipt of a second packet at a WAN interface, determine whether the received second packet is associated with an existing application flow in the flow cache;
• set a second attribute flag in the flow cache when the second packet is received at the WAN interface, wherein the second attribute flag identifies whether the apparatus is a WAN-side border router;
• in response to determining that the received second packet is associated with the first application flow in the flow cache, (i) set a first attribute flag in the flow cache when the second packet is received at the LAN interface, wherein the attribute flag identifies whether the apparatus is associated with a LAN-side border router and (ii) send the received second packet to a LAN-destination device associated with the LAN interface;
• and
• in response to determining that the received second packet is not associated with an existing application flow in the flow cache, forward the received second packet to a second border router over a tunnel interface, wherein the second border router is configured to send the second packet to the LAN-destination device upon a determination that the received second packet comprises, in a second flow cache maintained at the second border router, an association with the first application flow.