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PCE – OAM Handler in ABNO: a use case of code adaptation in flex grid networks PACE Workshop on “New uses of Path Computation Elements” Vilanova y la Geltru,

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Presentation on theme: "PCE – OAM Handler in ABNO: a use case of code adaptation in flex grid networks PACE Workshop on “New uses of Path Computation Elements” Vilanova y la Geltru,"— Presentation transcript:

1 PCE – OAM Handler in ABNO: a use case of code adaptation in flex grid networks PACE Workshop on “New uses of Path Computation Elements” Vilanova y la Geltru, Spain, June 16 th 2014 Francesco Paolucci TeCIP, Scuola Superiore Sant’Anna, Pisa, Italy

2 Control Management Control plane – Discovery and Routing – Path computation – Signaling – Failure recovery Management plane – Network Status and Monitoring – Operation and Administration Maintenance (OAM) – SLA verification Interaction between planes – Historical separation or limited interaction (not automatic) – New target: pro-active control automatically driven by OAM events/ conditions – Active Stateful Path Computation Element in ABNO candidate object

3 Active Stateful PCE – Access to TED and LSP-DB – Stateful computation Shared protection computation Effective restoration – Active behaviour Delegated LSP control LSP resize, modification LSP instantiation Optimization Action Chain OAM Handler – Network status supervisor – Monitoring correlations Databases – TED, LSP-DB ABNO architecture Application-Based Network Operation (ABNO) framework. “A PCE-based Architecture for Application-based Network Operations” draft-farrkingel-pce-abno-architecture

4 PCE in Flexible optical networks Next flexible transponders will support multiple configurable signal bitrate PCE outputs – Suggested frequency slots (n: central frequency, m: width ) – Suggested modulation format (e.g., DP-QPSK, DP-16QAM) – Suggested FEC / code – Single/multi carrier: type and number of sub-carriers Hitless flexible operations driven by active PCE – Defragmentation (change n) – Elastic operations (change m) – Dynamic adaptation (change the code) Advanced Action Chain – E.g. Defrag + Elastic expand

5 Chain Example: Shift & Expand 5 PCReq (LSP 1: Elastic bit rate increase) 1 2 PCUpd (LSP 2: Shift) 4 PCRpt (LSP 2: Shift OK) 5 PCRep (LSP 1: Elastic increase) 7 PCNtf (LSP 1: Elastic incresae OK) Frequency LSP 1 1 PCReq message 3 RSVP make before break 5 PCRep message 6 RSVP elastic increase 7 PCNtf message PCRpt message 4 PCUpd message 2 3 LSP 2 shift 6 LSP 1 elastic increase LSP 2

6 Code adaptation for flexi Terabit Terabit transmission based on Time Frequency Packing – LDPC coding applied to data – Narrow-filtered subcarriers (faster-than-Nyquist) – Coherent detection and DSP Scenario 1 – 7 160Gb/s – 200 GHz width – 8/9 coding – 1.12 Tb/s bitrate -> 1Tb/s info rate Scenario 2 – More robust transmission needed – 1 subcarrier added – 4/5 coding – GHz width – 1.28 Tb/s bit rate -> 1Tb/s info rate

7 QoT monitoring and forecast Quality of Transmission is monitored at the receiver – Post-FEC BER – Variance of acquired data samples Event Forecasting – The variance indicates whether a working limit condition is approaching – FORECASTING post-FEC errors before they occur – Threshold-based alarm event QoT monitor – Responsible of monitoring – Responsible of event ntf – Responsible of alarms

8 Validation Testbed (PCEP+RSVP)

9 PCE-driven code adaptation Impairment-aware PCE computes a new code rate: – Extended PCUpd message – The ERO specifies the code to be applied at ingress/egress node – LDPC code rate TLV Alarm triggered by PCEP: – Novel QoT notify msg – PCE computes the code – First implementation – PCEP not suitable for OAM – Path rerouting is the last option

10 Hitless data plane operations To apply the new coding – Configurable electrical encoder at transmitter, triggered upon RSVP- TE session is finished – In the overhead, a preamble of each data block includes a 3-bit field to communicate the code to be applied to the next block – Receiver processes next incoming data block with the new coding – Code adaptation performed with no traffic disruption

11 OAM infrastructure OAM Agent located at the receiver – OAM session per LSP (per receiver card) Hierarchical OAM Agent – Local Agent (node, link, network device…) – Aggregation Agent (area, domain…) – Local correlations when applicable – Scalable design Proposed OAM protocol: NETCONF – Support of Asynchronous Notifications (RFC 5277) – TCP connection assures reliability – Hierarchical architecture reduces number of connections at Handler – Native solution for OAM YANG modeling development OAM Handler LLLL L LL LL AA A

12 PCE driven by OAM

13 OAM Handler PCE interaction OAM Database instance ->Augmented TED / LSP-DB OAM LSP-DB:,,< …… OAM TED : <… Direct PCE OAM Handler interface needed? PCE OAM Handler PCEP TED OAM TED LSP-DB OAM LSP-DB NETCONF R R only (OAM-aware path computation) R/W OAM InstanceMain Instance 1) Through ABNO controller 2) PCEP (OAM:PCC) 3) Dedicated protocol 4) Internal API (if co-located)

14 Conclusions Proactive PCE – Fast reaction in presence of network degradations – Computation and dynamic update of additional parameters Presented use case – Hitless code rate adaptation in next generation transponders – Active PCE in charge of computing the most suitable adaptation – Advanced monitoring functions ABNO boxes interaction – Close relationship between OAM Handler and PCE – Proposed Hierarchical OAM infrastructure with NETCONF – Dedicated database extensions/sessions populated by OAM – Shared handling of the ABNO database sessions

15 Thank you Francesco Paolucci, Scuola Superiore Sant’Anna ACKNOWLEDGMENTS -collaboration with IDEALIST project Questions are welcome


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