# US 12,003,398 B2 · Round-trip performance measurement in a packet-switched communication network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,398 B2 - Document ID: US12003398B2 - Status: Granted - Kind: B2 - Application number: 16/957,610 - Filed: 2018-12-21 - Published: 2020-10-22 - Granted: 2024-06-04 - Earliest claimed: 2017-12-27 - Assignees: Telecom Italia S.p.A. - Applicants: TELECOM ITALIA S.p.A. - Inventors: Mauro Cociglio; Luca Fantolino; Giuseppe Fioccola; Angelo Franceschini - Web page: https://patentgrep.com/patent/US12003398B2 ## CPC - H04L 43/0864: Round trip delays - H04L 12/4633: {Interconnection of networks using encapsulation techniques, e.g. tunneling} - H04L 12/4641: {Virtual LANs, VLANs, e.g. virtual private networks [VPN] (LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272)} - H04L 43/08: Monitoring or testing based on specific metrics, e.g. QoS, energy consumption or environmental parameters - H04L 43/10: Active monitoring, e.g. heartbeat, ping or trace-route - H04L 43/50: Testing arrangements - H04L 45/50: using label swapping, e.g. multi-protocol label switch [MPLS] - H04L 47/283: in response to processing delays, e.g. caused by jitter or round trip time [RTT] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract In a method for measurement of a round-trip performance in a packet-switched communication network, a measurement device cooperating with the communication network generates a flow of test packets formatted according to the network protocol supported by the network and comprising the address of the measurement device as destination address. The test packets are then transmitted within a tunnel set up in the network and the measurement device generates one or more transmission parameters. At the end of the tunnel, the test packets are extracted therefrom and sent back to the measurement device by the forwarding function of the network protocol supported by the network. Upon receipt of the test packets, it generates one or more reception parameters, which are then combined with the transmission parameters to provide the round-trip performance measurement. ## Claims ### Claim 1 A method for performing a round-trip performance measurement in a packet-switched communication network supporting a network protocol, said method comprising: a) at a measurement device cooperating with said communication network, generating a flow of test packets formatted according to said network protocol and comprising packet forwarding information suitable for inducing said communication network to forward said test packets to said measurement device b) transmitting said test packets within a tunnel set up in said communication network and, while said test packets are transmitted, generating, at said measurement device, at least one transmission parameter; c) after said test packets have been extracted from said tunnel, forwarding back said test packets to said measurement device based on said packet forwarding information and, while said test packets extracted from said tunnel are received at said measurement device, generating, at said measurement device, at least one reception parameter; and d) performing, at said measurement device, said round-trip performance measurement based on said at least one transmission parameter and said at least one reception parameter, wherein step b) includes transmitting said test packets from said measurement device to a first node of said packet-switched communication network, said first node is adjacent to and distinct from said measurement device, said tunnel is originated at said first node, at step b) said tunnel is terminated at a second node of said communication network, said second node: extracts said test packets from said tunnel, and based on a rule overruling default forwarding criteria of said second node, forces transmission of said test packets to a target node of said communication network, said target node is adjacent to and distinct from said second node, and said target node, which is adjacent to said second node, forwards back said test packets to said measurement device based on said packet forwarding information. ### Claim 2 (depends on 1) The method according to claim 1, wherein said packet forwarding information is comprised in a header of each test packet. ### Claim 3 (depends on 2) The method according to claim 2, wherein said packet forwarding information comprises an address of said measurement device, said address being written by said measurement device in a destination address field of the header of each generated test packet. ### Claim 4 (depends on 1) The method according to claim 1, wherein said step b) comprises: at the ingress of said tunnel, inserting each test packet in said tunnel by prefixing a tunnel header thereto; and at the exit of said tunnel, extracting each test packet from said tunnel by removing said tunnel header therefrom. ### Claim 5 (depends on 1) The method according to claim 1, wherein step b) comprises, at said first node, identifying said test packets received from said measurement device and inserting said test packets within said tunnel, said test packets being identified based on one or more of the following information: an identifier of a logical ingress or a logical interface through which said test packets are received at said first node; a destination address of said test packets; and a destination port of said test packets. ### Claim 6 (depends on 1) The method according to claim 1, wherein at step b) said target node forwards said test packets back to said measurement device based on said packet forwarding information comprised in said test packets, by using a forwarding engine and forwarding table comprised in said target node. ### Claim 7 (depends on 1) The method according to claim 1, wherein step b) comprises locally storing at said measurement device said at least one transmission parameter. ### Claim 8 (depends on 1) The method according to claim 1, wherein: step b) comprises inserting values of said at least one transmission parameter in said test packets, before they are transmitted within said tunnel; and step c) comprises extracting said values of said at least one transmission parameter from said test packets extracted from said tunnel and received at said measurement device. ### Claim 9 (depends on 1) The method according to claim 1, wherein: at step b), said at least one transmission parameter further comprises a transmission counter to count a number of test packets transmitted by said measurement device; and at step c), said at least one reception parameter comprises a reception counter counting a number of test packets received by said measurement device and/or, for each received test packet, a respective reception timestamp indicating a time at which said test packet has been received by said measurement device. ### Claim 10 (depends on 1) The method according to claim 1, wherein said measurement device is a measurement function embedded within a node of said communication network. ### Claim 11 (depends on 1) The method according to claim 1, wherein the test packets are generated at a rate corresponding to a desired measurement precision. ### Claim 12 (depends on 1) The method according to claim 1, wherein the network protocol is IP (Internet Protocol) and said tunnel is implemented as a virtual private network. ### Claim 13 (depends on 1) The method according to claim 1, wherein each test packet includes a test packet identifier in a payload section thereof. ### Claim 14 (depends on 13) The method according to claim 13, wherein the at least one transmission parameter includes, for each transmitted test packet, a respective transmission timestamp indicating a time at which said test packet has been transmitted by said measurement device. ### Claim 15 (depends on 14) The method according to claim 14, further comprising storing, at the measurement device, at least one of: each transmission timestamp corresponding to a test packet in association with the test packet identifier corresponding to the test packet, or an ordered sequence of transmission timestamps. ### Claim 16 (depends on 1) The method according to claim 1, wherein each test packet includes a plurality of padding bits to reach a desired test packet size. ### Claim 17 A system comprising: a measurement device for performing a round-trip performance measurement in a packet-switched communication network supporting a network protocol, said measurement device comprising at least one processor configured to implement: a test packet generator configured to generate a flow of test packets formatted according to said network protocol and comprising packet forwarding information suitable for inducing said communication network to forward said test packets to said measurement device; a first node comprising at least one processor configured to implement: a packet encapsulator configured to implement a tunnel in said communication network and transmit said test packets within the tunnel; and a second node comprising at least one processor configured to implement: a packet de-encapsulator PDE configured to terminate the tunnel by extracting said test packets from the tunnel, wherein the at least one processor of the measurement device is further configured to implement: a measurement point configured to: while said test packets are transmitted from said measurement device, generate at least one transmission parameter; while said test packets extracted from said tunnel and forwarded back to said measurement device based on said packet forwarding information received at said measurement device, generate at least one reception parameter; and perform said round-trip performance measurement based on said at least one transmission parameter and said at least one reception parameter, said first node that implements, via said packet encapsulator, said tunnel is adjacent to and distinct from said measurement device, said second node, based on a rule overruling default forwarding criteria of said second node, forces transmission of said test packets to a target node of said communication network, said target node is adjacent to and distinct from said second node, and said target node, which is adjacent to said second node, forwards back said test packets to said measurement device based on said packet forwarding information. ### Claim 18 (depends on 17) The measurement device according to claim 17, wherein the network protocol is IP (Internet Protocol) and said tunnel is implemented as a virtual private network.