Round trip time (RTT) measurement based upon sequence number

ChangeBridge: Patent Grants - Networking (H04L)

Published April 7th, 2026

Detected April 7th, 2026

Summary

The USPTO granted Cisco Technology, Inc. Patent US12596568B2 covering systems and methods for measuring packet round trip time (RTT) in networks using sequence numbers. The patent describes determining expected ACK sequence numbers and comparing them with received sequence numbers to calculate network latency. Cisco is the assignee with six named inventors.

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What changed

USPTO granted Cisco a new patent covering RTT measurement methods in network communications. The patent describes systems that receive packet information, determine expected ACK sequence numbers, compare them with received sequence numbers from subsequent packets, and calculate round trip time when matches occur. This enables more accurate network latency measurement using TCP sequence number tracking.

For Cisco, the patent establishes enforceable intellectual property rights that may support technology licensing opportunities or defensive positioning in network communications. The patent covers networking equipment and software implementations for latency measurement. The patent has 20 claims spanning network protocols, data structures, and system architectures for RTT calculation.

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Source document (simplified)

← USPTO Patent Grants

Round trip time (RTT) measurement based upon sequence number

Grant US12596568B2 Kind: B2 Apr 07, 2026

Assignee

Cisco Technology, Inc.

Inventors

Mohammadreza Attar, Navindra Yadav, Abhishek Ranjan Singh, Vimalkumar Jeyakumar, Shashidhar Gandham, Roberto Fernando Spadaro

Abstract

Systems, methods, and computer-readable media are provided for determining a packet's round trip time (RTT) in a network. A system can receive information of a packet sent by a component of the network and further determine an expected acknowledgement (ACK) sequence number associated with the packet based upon received information of the packet. The system can receive information of a subsequent packet received by the component and determine an ACK sequence number and a receiving time of the subsequent packet. In response to determining that the ACK sequence number of the subsequent TCP packet matches the expected ACK sequence number, the system can determine a round trip time (RTT) of the packet based upon the received information of the packet and the received information of the subsequent packet.

CPC Classifications

H04L 43/045 H04L 1/242 H04L 7/10 H04L 9/0866 H04L 9/3239 H04L 9/3242 H04L 41/046 H04L 41/0668 H04L 41/0803 H04L 41/0806 H04L 41/0816 H04L 41/0893 H04L 41/12 H04L 41/16 H04L 41/22 H04L 43/02 H04L 43/026 H04L 43/04 H04L 43/062 H04L 43/08 H04L 43/0805 H04L 43/0811 H04L 43/0829 H04L 43/0841 H04L 43/0858 H04L 43/0864 H04L 43/0876 H04L 43/0882 H04L 43/0888 H04L 43/10 H04L 43/106 H04L 43/12 H04L 43/16 H04L 45/306 H04L 45/38 H04L 45/46 H04L 45/507 H04L 45/66 H04L 45/74 H04L 47/11 H04L 47/20 H04L 47/2441 H04L 47/2483 H04L 47/28 H04L 47/31 H04L 47/32 H04L 61/5007 H04L 63/0227 H04L 63/0263 H04L 63/06 H04L 63/0876 H04L 63/1408 H04L 63/1416 H04L 63/1425 H04L 63/1433 H04L 63/1441 H04L 63/145 H04L 63/1458 H04L 63/1466 H04L 63/16 H04L 63/20 H04L 67/01 H04L 67/10 H04L 67/1001 H04L 67/12 H04L 67/51 H04L 67/75 H04L 69/16 H04L 69/22 H04L 67/535 H04L 41/40 H04L 43/20 H04L 41/0894 G06F 3/0482 G06F 3/04842 G06F 3/04847 G06F 9/45558 G06F 16/122 G06F 16/137 G06F 16/162 G06F 16/17 G06F 16/173 G06F 16/174 G06F 16/1744 G06F 16/1748 G06F 16/2322 G06F 16/235 G06F 16/2365 G06F 16/24578 G06F 16/248 G06F 16/285 G06F 16/288 G06F 16/29 G06F 16/9535 G06F 21/53 G06F 21/552 G06F 21/556 G06F 21/566 G06F 2009/4557 G06F 2009/45587 G06F 2009/45591 G06F 2009/45595 G06F 2221/033 G06F 2221/2101 G06F 2221/2105 G06F 2221/2111 G06F 2221/2115 G06F 2221/2145 G06N 20/00 G06N 99/00 G06T 11/206 H04J 3/0661 H04J 3/14 H04W 72/54 H04W 84/18