The complaint
The case is Portsmouth Network Corporation v. Cisco Systems, Inc., No. 2:26-cv-00788-JRG (E.D. Tex.), filed September 3, 2026 in the Marshall Division with a jury demand. Portsmouth is a Delaware corporation based in Middleton, Massachusetts. The complaint says the patents came out of a telecommunications equipment developer's Ethernet switching and routing work between 2000 and 2010, and that Portsmouth acquired all rights in them.
The patents and accused products
U.S. Patent 7,035,279, titled Flow allocation in a ring topology, issued April 25, 2006; claim 1 covers routing a data flow by allocating quanta of network resources to each node and, when a node's allocation is insufficient for a requested flow, requesting more, measuring use of the resource on the links of each candidate path, choosing the path on that basis, and increasing the node's allocation on that path by a predetermined quantum. U.S. Patent 7,154,899, titled Protecting the filtering database in virtual bridges, issued December 26, 2006; claim 1 covers budgeted learning of link information, adding a new database entry learned from traffic only if additions during the learning period have not exceeded a set maximum rate, where the rate is set as a budget of entries that is decremented as entries are added. U.S. Patent 7,420,922, titled Ring network with variable rate, issued September 2, 2008; claim 1 covers a manager node exchanging validation messages with other nodes, while they communicate at a first rate, to verify they can switch to a second rate, then commanding a rate change so that three or more nodes switch substantially simultaneously. U.S. Patent 7,626,930, titled Hash-based multi-homing, issued December 1, 2009; claim 1 covers assigning ports in two or more network nodes to a multi-homing group, each port tied to a different path between two nodes, and choosing the single port for each frame by applying a hashing function to header fields at each node. U.S. Patent 7,773,508, also titled Protecting the filtering database in virtual bridges, issued August 10, 2010; claim 1 covers a similar budgeted learning method in which the budget allocates a number of entries to the entity so that the entries added during the learning period do not exceed the database's total. U.S. Patent 8,199,637, titled VPLS remote failure indication, issued June 12, 2012; claim 1 covers provisioning two instances of a multipoint-to-multipoint service over alternative sets of links and, when a failure is detected in the first set, propagating failure information to the other nodes on that set, which deactivate the physical layer of their links so that the loss of connectivity triggers an automatic transfer of the service to the second instance.
The complaint accuses Cisco ASR 9000 Series Routers of infringing the '637 patent, Cisco Catalyst 9000 Switches of infringing the '279, '922, '930, and '637 patents, and Cisco Nexus 9000 Switches of infringing the '899 and '508 patents, and says the list is not limiting. Each count asserts at least claim 1, compared to the accused products in claim charts attached as Exhibits 7 through 12, and pleads direct, induced, and contributory infringement.
Knowledge and willfulness allegations
Portsmouth alleges that a prior owner of the patents wrote to Cisco about the portfolio on March 20, 2017 and July 11, 2018, and identified the '637 patent in a November 20, 2018 email. It also alleges knowledge from its earlier suit against Cisco, Portsmouth Network Corporation v. Cisco Systems, Inc., No. 2:23-cv-441 (E.D. Tex.), filed September 26, 2023, and alleges that Cisco's infringement has been willful. The prayer asks for a permanent injunction, damages, treble damages, attorneys' fees under 35 U.S.C. 285, costs, and interest.
What to watch next
The case is assigned to District Judge Rodney Gilstrap, according to the September 3, 2026 assignment entry. The docket shows an unopposed application to extend Cisco's time to answer on September 11 (ECF No. 8) and an order setting scheduling order deadlines on October 21, 2026 (ECF No. 10). Watch for Cisco's answer or Rule 12 motion and any motion to transfer or stay.