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US-20260128980-A1 - Delay-based Availability as a TE attribute for Segment Routing

US20260128980A1US 20260128980 A1US20260128980 A1US 20260128980A1US-20260128980-A1

Abstract

Systems and methods for delay-based availability include performing delay measurements with one or more nodes in the Segment Routing network on corresponding links to the one or more nodes; utilizing the delay measurements to determine delay-based availability of the corresponding links to the one or more nodes, wherein the delay-based availability describes how often a given link of the corresponding links is available in terms of quantum time intervals over a measurement interval; and advertising details of the delay-based availability in the Segment Routing network for use as a delay-based availability metric for use as a traffic engineering (TE) metric.

Inventors

  • Pankaj Verma
  • Aditya Mittal

Assignees

  • CIENA CORPORATION

Dates

Publication Date
20260507
Application Date
20241220
Priority Date
20241106

Claims (20)

  1. 1 . A node in a Segment Routing network comprising circuitry configured to: perform delay measurements with one or more nodes in the Segment Routing network on corresponding links to the one or more nodes, utilize the delay measurements to determine delay-based availability of the corresponding links to the one or more nodes, wherein the delay-based availability describes how often a given link of the corresponding links is available in terms of quantum time intervals over a measurement interval, and advertise details of the delay-based availability in the Segment Routing network for use as a delay-based availability metric for use as a traffic engineering (TE) metric.
  2. 2 . The node of claim 1 , wherein the circuitry is further configured to advertise details of the delay measurements for an average forward delay metric for use as another TE metric along with the delay-based availability metric.
  3. 3 . The node of claim 1 , wherein the delay-based availability is determined where the delay measurements are used to compare to a delay threshold for each quantum time interval to determine an available indicator and an unavailable indicator.
  4. 4 . The node of claim 3 , wherein the delay-based availability metric for a given measurement interval is based on [Available Indicator/(Available Indicator+Unavailable Indicator)].
  5. 5 . The node of claim 1 , wherein the delay-based availability is determined utilizing a loss-based availability algorithm defined in Metro Ethernet Forum (MEF) 10.3/35.1 where the delay measurements are used to compare to a delay threshold for each quantum time interval.
  6. 6 . The node of claim 1 , wherein the delay measurements utilize one of Two-Way Active Measurement Protocol (TWAMP) sessions and Simple Two-Way Active Measurement Protocol (STAMP).
  7. 7 . The node of claim 1 , wherein the details of the delay-based availability are advertised in a delay-based availability sub-Type-Length-Value (TLV).
  8. 8 . The node of claim 1 , wherein the details of the delay-based availability are advertised in a Flexible Algorithm Definition sub-Type-Length-Value (TLV).
  9. 9 . The node of claim 1 , wherein the circuitry is further configured to receive advertisements of details of the delay-based availability for other links from other nodes in the Segment Routing network, and utilize the delay-based availability for links in the Segment Routing network for TE path computation.
  10. 10 . The node of claim 9 , wherein the TE path computation selects a path in the Segment Routing network based on the delay-based availability and based on average forward delay metric, such that a path having highest delay-based availability is selected.
  11. 11 . A method comprising steps of: performing delay measurements with one or more nodes in a Segment Routing network on corresponding links to the one or more nodes; utilizing the delay measurements to determine delay-based availability of the corresponding links to the one or more nodes, wherein the delay-based availability describes how often a given link of the corresponding links is available in terms of quantum time intervals over a measurement interval; and advertising details of the delay-based availability in the Segment Routing network for use as a delay-based availability metric for use as a traffic engineering (TE) metric.
  12. 12 . The method of claim 11 , wherein the steps further include advertising details of the delay measurements for an average forward delay metric for use as another TE metric along with the delay-based availability metric.
  13. 13 . The method of claim 11 , wherein the delay-based availability is determined where the delay measurements are used to compare to a delay threshold for each quantum time interval to determine an available indicator and an unavailable indicator.
  14. 14 . The method of claim 13 , wherein the delay-based availability metric for a given measurement interval is based on [Available Indicator/(Available Indicator+Unavailable Indicator)].
  15. 15 . The method of claim 11 , wherein the delay-based availability is determined utilizing a loss-based availability algorithm defined in Metro Ethernet Forum (MEF) 10.3/35.1 where the delay measurements are used to compare to a delay threshold for each quantum time interval.
  16. 16 . The method of claim 11 , wherein the delay measurements utilize one of Two-Way Active Measurement Protocol (TWAMP) sessions and Simple Two-Way Active Measurement Protocol (STAMP).
  17. 17 . The method of claim 11 , wherein the details of the delay-based availability are advertised in a delay-based availability sub-Type-Length-Value (TLV).
  18. 18 . The method of claim 11 , wherein the details of the delay-based availability are advertised in a Flexible Algorithm Definition sub-Type-Length-Value (TLV).
  19. 19 . The method of claim 11 , wherein the steps further include receiving advertisements of details of the delay-based availability for other links from other nodes in the Segment Routing network; and utilizing the delay-based availability for links in the Segment Routing network for TE path computation.
  20. 20 . The method of claim 19 , wherein the TE path computation selects a path in the Segment Routing network based on the delay-based availability and based on average forward delay metric, such that a path having highest delay-based availability is selected.

Description

FIELD OF THE DISCLOSURE The present disclosure relates generally to networking and computing. More particularly, the present disclosure relates to systems and methods for delay-based availability as a traffic engineering (TE) attribute for Segment Routing, for dynamic path computation, flexible algorithm, etc. BACKGROUND OF THE DISCLOSURE Segment Routing Traffic Engineering (SR-TE) is a network routing paradigm that leverages the principles of Segment Routing (SR) to enable precise path control for traffic flows within an Internet Protocol/Multiprotocol Label Switching (IP/MPLS) network. SR-TE uses a sequence of segments, which are instructions encoded as labels, to direct traffic along a specified path. This approach eliminates the need for complex signaling protocols, such as Resource Reservation Protocol—Traffic Engineering (RSVP-TE), simplifying network operations. With SR-TE, operators can optimize network performance, increase scalability, and achieve more flexible and granular traffic management. By defining specific paths through the network, SR-TE supports advanced applications such as load balancing, latency optimization, and bandwidth reservation, making it particularly suitable for service providers aiming to enhance network efficiency and reliability. One key attribute for SR-TE is availability which is a performance metric that indicates the proportion of time a network (or service/path) is operational, accessible and usable. The conventional approach only considers a forward delay measurement of a link or path. BRIEF SUMMARY OF THE DISCLOSURE The present disclosure relates to systems and methods for delay-based availability as a traffic engineering (TE) attribute for Segment Routing. In SR-TE, availability is a critical performance metric used to assess the reliability of network paths and resources. Availability measures the percentage of time that a network path or service is operational and capable of handling traffic without interruptions. High availability is essential for ensuring continuous network service, especially for applications with strict uptime requirements. SR-TE enables operators to select paths based on availability metrics, allowing for the prioritization of routes that maximize uptime and minimize potential disruptions. By leveraging availability as a metric, SR-TE can dynamically adjust traffic flows to optimize network resilience and ensure that traffic is routed over the most reliable paths. This approach enhances the network's ability to meet service level agreements (SLAs) and provides improved overall user experience by reducing downtime and maintaining consistent service quality. The present disclosure provides a delay-based availability attribute which combines traditional delay (or latency) key performance indicators (KPIs) with an availability algorithm. This provides a more nuanced view of network performance having specific applicability in scenarios where the network is required to meet specific delay thresholds for a longer duration which is critical to meet SLAs and performance. The advantages of using the delay-based availability over the traditional delay include: (1) KPIs like packet delay focus solely on delay offering a narrower perspective and do not provide the complete picture of service/path availability.(2) Availability KPIs are closely aligned with SLAs that define acceptable levels of service/transport uptime/performance.(3) Availability KPIs provide actual time path/service is accessible/usable with desired performance, directly serving as an important guideline for path selection to enhance available time. In various embodiments, the present disclosure contemplates implementation as a method with steps, via a node or apparatus with circuitry configured to implement the steps, and as a non-transitory computer-readable medium storing instructions that, when executed, cause circuitry to implement the steps. The steps include performing delay measurements with one or more nodes in a Segment Routing network on corresponding links to the one or more nodes; utilizing the delay measurements to determine delay-based availability of the corresponding links to the one or more nodes, wherein the delay-based availability describes how often a given link of the corresponding links is available in terms of quantum time intervals over a measurement interval; and advertising details of the delay-based availability in the Segment Routing network for use as a delay-based availability metric for use as a traffic engineering (TE) metric. The steps can further include advertising details of the delay measurements for an average forward delay metric for use as another TE metric along with the delay-based availability metric. The delay-based availability can be determined where the delay measurements are used to compare to a delay threshold for each quantum time interval to determine an available indicator and an unavailable indicator. The delay-based availability me