Huawei Ultra Broadband Forum 2018

SDN-Enabled IP and Optical Integration

IP and optical integration has long been a dream in the telecommunications industry: A quick Google search turns up discussions of "IP over glass" going at least as far back as 1998.

The concept of IP over glass was to eliminate the ATM and Sonet/SDH layers and transport IP packets directly over WDM, thus saving on network layers and equipment. Forebodingly, Enron was a leading champion of this architectural concept, which died out along with the energy trader.

During the 2000s, IP over DWDM (or IPoDWDM) introduced the direct, physical integration of DWDM optics on IP routers. Despite the obvious capex savings benefit of removing the need for back-to-back transponders in the network, IPoDWDM suffered from a major capex drawback of its own. Long reach optics have historically been larger than comparable generation short reach interfaces. As a result, operators have preferred to pack their routers with smaller short reach interfaces to get the most use of their costly IP router processing capacity. They’ve kept the DWDM optics on separate hardware.

Today, a new wave of IP and optical integration interest is taking hold, one which, in our view, has much greater promise than the previous two generations. Commonly called IP+optical, the new trend calls for a coupling of control and management of the IP and optical layers but with the data planes being kept in separate hardware devices.

Such software-level integration yields many of the operations and some of the capex savings of physical integration while avoiding the uneconomical faceplate trade-offs that reduce the value of full physical integration. The Open Networking Foundation (ONF), in a recently published technical paper entitled Optical Transport Use Cases, describes the values of control integration of IP and optical layers as follows:

  • Capex reduction, by reducing the need for over-provisioning of the network to support demand shifts and protection/restoration, through the integration of control over packet and optical networks;

  • Increased service availability (via coordinated protection and restoration) and service quality (via latency-optimized multi-layer provisioning) based on integrated reactions to changes in network conditions;

  • Opex reduction and simplification through automation to reduce manual processes and associated configuration errors, compared to separate control structures and manual coordination;

  • Increased revenue, using network intelligence to monetize the network based on programmable path and service level parameters, such as end-to-end latency of packet service.

Although IP+optical integration does not require it from a technical standpoint, SDN, with its emphasis on software programmability, openness, and standardization, is emerging as the best long term means to accomplish IP+optical integration. This is because an SDN-based IP+optical network architecture opens the possibility of integration that is both multi-layer and multi-vendor.

For this reason, Heavy Reading believes that IP and optical integration and carrier SDN progress will be closely aligned moving forward.

— Sterling Perrin, Senior Analyst, Heavy Reading

DHagar 9/22/2014 | 4:20:22 PM
Re: Optical should mean more than transport mbushong, sounds as if you are making valued break-throughs in increasing the capacity.  Sounds like a smart move that will advance your products and the markets overall.

This article is great in demonstrating capabilities that we can further develop.
@mbushong 9/11/2014 | 11:13:06 AM
Re: Optical should mean more than transport Because 80% of traffic is east-west is exactly why we will see more optical solutions in the data center. Traditional networking says to put bandwidth everywhere because capacity is static. Programmable paths say put capacity in the network and provision it as you need it. I don't think we will get to granular provisioning (moving things every second), but you can set up capacity for applications and tenants, adding a degree of dynamism to what is normally a static environment.

Happy to chat about tech whenever. Drop me a line at first.last at Plexxi.com.

Michael Bushong (@mbushong)
Sterling Perrin 9/11/2014 | 11:06:01 AM
Re: Optical should mean more than transport Mike,

I'm intrigued by your comment, particuarly given that service providers are telling me that 80%+ of data center traffic stays within the DC itself, leaving optical transport to address just 10-20% of what is being generated. 

I have not followed this within the DC optics trend much so far but would be interested in a briefing on what you are up to, if you'd like to get in touch. And thanks for your interest in the blog!


@mbushong 9/11/2014 | 10:55:24 AM
Optical should mean more than transport The idea of programmable paths being paired with central intelligence is powerful. But it probably isn't limited to just transport. WDM can be extended to the datacenter to create what looks a lot like a metroE deployment within the datacenter. The programmable paths can then be tuned to applications and tenants, providing performance guarantees and tenant/application isolation along wavelengths. 

Mike Bushong (@mbushong)

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