Linux Foundation

TC3 Update on CORD (Central Office Re-architected as a Data center)

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Introduction:

Timon Sloane of the Open Networking Foundation (ONF) provided an update on project CORD on November 1st at the Telecom Council’s Carrier Connections (TC3) summit in Mt View, CA.  The session was titled:

Spotlight on CORD: Transforming Operator Networks and Business Models

After the presentation, Sandhya Narayan of Verizon and Tom Tofigh of AT&T came up to the stage to answer a few audience member questions (there was no real panel session).

The basic premise of CORD is to re-architect a telco/MSO central office to have the same or similar architecture of a cloud resident data center.  Not only the central office, but also remote networking equipment in the field (like an Optical Line Termination unit or OLT) are decomposed and disaggregated such that all but the most primitive functions are executed by open source software running on a compute server.  The only hardware is the Physical layer transmission system which could be optical fiber, copper, or cellular/mobile.

Author’s Note:  Mr. Sloane didn’t mention that ONF became involved in project CORD when it merged with ON.Labs earlier this year. At that time, the ONOS and CORD open source projects became ONF priorities.  The Linux Foundation still lists CORD as one of their open source projects, but it appears the heavy lifting is being done by the new ONF as per this press release.

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Backgrounder:

A reference implementation of CORD combines commodity servers, white-box switches, and disaggregated access technologies with open source software to provide an extensible service delivery platform. This gives network operators (telcos and MSOs) the means to configure, control, and extend CORD to meet their operational and business objectives. The reference implementation is sufficiently complete to support field trials.

Illustration above is from the OpenCord website

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Highlights of Timon Sloane’s CORD Presentation at TC3:

  • ONF has transformed over the last year to be a network operator led consortium.
  • SDN, Open Flow, ONOS, and CORD are all important ONF projects.
  • “70% of world wide network operators are planning to deploy CORD,” according to IHS-Markit senior analyst Michael Howard (who was in the audience- see his question to Verizon below).
  • 80% of carrier spending is in the network edge (which includes the line terminating equipment and central office accessed).
  • The central office (CO) is the most important network infrastructure for service providers (AKA telcos, carriers and network operators, MSO or cablecos, etc).
  • The CO is the service provider’s gateway to customers.
  • End to end user experience is controlled by the ingress and egress COs (local and remote) accessed.
  • Transforming the outdated CO is a great opportunity for service providers.  The challenge is to turn the CO into a cloud like data center.
  • CORD mission is the enable the “edge cloud.”                                               –>Note that mission differs from the OpenCord website which states:

    “Our mission is to bring datacenter economies and cloud agility to service providers for their residential, enterprise, and mobile customers using an open reference implementation of CORD with an active participation of the community. The reference implementation of CORD will be built from commodity servers, white-box switches, disaggregated access technologies (e.g., vOLT, vBBU, vDOCSIS), and open source software (e.g., OpenStack, ONOS, XOS).” 

  • A CORD like CO infrastructure is built using commodity hardware, open source software, and white boxes (e.g. switch/routers and compute servers).
  • The agility of a cloud service provider depends on software platforms that enable rapid creation of new services- in a “cloud-like” way. Network service providers need to adopt this same model.
  • White boxes provide subscriber connections with control functions virtualized in cloud resident compute servers.
  • A PON Optical Line Termination Unit (OLT) was the first candidate chosen for CORD.  It’s at the “leaf of the cloud,” according to Timon.
  • 3 markets for CORD are:  Mobile (M-), Enterprise (E-), and Residential (R-).  There is also the Multi-Service edge which is a new concept.
  • CORD is projected to be a $300B market (source not stated).
  • CORD provides opportunities for: application vendors (VNFs, network services, edge services, mobile edge computing, etc), white box suppliers (compute servers, switches, and storage), systems integrators (educate, design, deploy, support customers, etc).
  • CORD Build Event was held November 7-9, 2017 in San Jose, CA.  It explored CORD’s mission, market traction, use cases, and technical overview as per this schedule.

Service Providers active in CORD project:

  • AT&T:  R-Cord (PON and g.fast), Multi-service edge-CORD, vOLTHA  (Virtual OLT Hardware Abstraction)
  • Verizon:  M-Cord
  • Sprint:  M-Cord
  • Comcast:  R-Cord
  • Century Link: R-Cord
  • Google:  Multi-access CORD

Author’s Note:  NTT (Japan) and Telefonica (Spain) have deployed CORD and presented their use cases at the CORD Build event.  Deutsche Telekom, China Unicom, and Turk Telecom are active in the ONF and may have plans to deploy CORD?

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Q&A Session:

  • This author questioned the partitioning of CORD tasks and responsibility between ONF and Linux Foundation.  No clear answer was given.  Perhaps in a follow up comment?
  • AT&T is bringing use cases into ONF for reference platform deployments.
  • CORD is a reference architecture with systems integrators needed to put the pieces together (commodity hardware, white boxes, open source software modules).
  • Michael Howard asked Verizon to provide commercial deployment status- number, location, use cases, etc.  Verizon said they can’t talk about commercial deployments at this time.
  • Biggest challenge for CORD:  Dis-aggregating purpose built, vendor specific hardware that exist in COs today.  Many COs are router/switch centric, but they have to be opened up if CORD is to gain market traction.
  • Future tasks for project CORD include:  virtualized Radio Access Network (RAN), open radio (perhaps “new radio” from 3GPP release 15?), systems integration, and inclusion of micro-services (which were discussed at the very next TC3 session).

Addendum from Marc Cohn, formerly with the Linux Foundation:

Here’s an attempt to clarify the CORD project responsibilities:

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