US 9,813,257 B2
Access network dual path connectivity
Srikanth Keesara, Tewksbury, MA (US); Sakthivadivu Saravanaraj, Nashua, NH (US); Liming Sun, Westford, MA (US); and Xiaolan Zhou, Carlisle, MA (US)
Assigned to Extreme Networks, Inc., San Jose, CA (US)
Filed by Srikanth Keesara, Tewksbury, MA (US); Sakthivadivu Saravanaraj, Nashua, NH (US); Liming Sun, Westford, MA (US); and Xiaolan Zhou, Carlisle, MA (US)
Filed on Oct. 19, 2010, as Appl. No. 12/907,535.
Claims priority of provisional application 61/381,678, filed on Sep. 10, 2010.
Prior Publication US 2012/0063465 A1, Mar. 15, 2012
Int. Cl. H04L 12/46 (2006.01); H04L 12/26 (2006.01); H04L 12/703 (2013.01); H04L 12/707 (2013.01)
CPC H04L 12/4633 (2013.01) [H04L 43/0811 (2013.01); H04L 45/28 (2013.01); H04L 45/22 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method of connecting a transport network and an access network, the access network providing connectivity between the transport network and a plurality of end stations coupled to the access network, the method comprising:
defining a switching device and a partner device, the switching device and the partner device each coupled to the access network via a respective link;
configuring a first static route to the access network between the switching device and an origin device;
configuring a second static route to the access network between the partner device and the origin device;
configuring a dynamic route between the origin device, the switching device, and the partner device in the transport network, the switching device and the partner device sharing the dynamic route; and
maintaining connectivity, via the dynamic route, from the origin device to the access network via at least one of the switching device and the partner device independently of failure of the switching device or the partner device or failure of either of the respective links,
wherein:
the dynamic route defines a respective tunnel through the transport network to each of the switching device and the partner device, each respective tunnel defining a separate physical path to the access network, wherein the dynamic route is identifiable by a single routing entry that allows the single routing entry to designate multiple physical paths through the transport network;
the dynamic route comprises a shared virtual tunnel across the transport network from the origin device to both of the switching device and the partner device;
the shared virtual tunnel is associated with a single virtual address;
the single virtual address is used by more than one device in the access network as a sender address and by more than one device in the access network to receive data frames bearing the single virtual address as a receiver address; and
traffic addressed to the single virtual address is forwarded to the access network by one of the switching device or the partner device.