Light Reading

Accelerating Packet-Optical Convergence

Sterling Perrin

In March, a group of leading network operators, led by Telefónica, published a white paper entitled "IP and Optical Convergence: Use Cases and Technical Requirements." The objective of this paper, as the authors write, was to outline the benefits, enablers, and challenges for IP and optical convergence, and the rationale for encouraging international collaboration to accelerate progress and development in this area.

In addition to Telefónica SA (NYSE: TEF), other contributing companies were: AXTEL Mexico; Bouygues Telecom; BT Group; China Unicom; Colt Telecom; Deutsche Telekom; KDDI; KT Corp. (Korea Telecom); Orange; and Telecom Italia.

The operator group assessed the value of a number of different IP and optical use cases. This blog focuses on multi-layer management, multi-layer planning, and multi-layer resilience, which garnered the most interest among the operator group -- and by a large margin.

The white paper looks at multi-layer resilience and focuses on an IP and optical layer resilience scheme that uses fast reroute (FRR) at the IP layer and GMPLS at the optical layer. The multi-layer network reduces operator capex by eliminating some of the requirements for 1+1 protection in the network. With traditional 1+1 protection, 50% of network capacity is reserved for backup in case a failure occurs, but a multi-layer control plane can be built to use 1:1 protection only when necessary.

While this paper does not provide multi-layer resilience savings statistics, DT research work published in 2012 demonstrated capex savings of 24-27% using a combination of IP layer and photonic layer restoration when compared to traditional network architectures implying IP layer restoration with full 1+1 protection. We have also seen equipment vendors cite even higher capex savings potential for this application.

Looking at multi-layer planning and management, a full integration of IP and optical layers can lead to better network manageability, but the complexity of full interaction (today, at least) requires a single vendor proprietary implementation. On the plus side, a proprietary integrated approach can speed up and simplify provisioning, fault management, and network planning. On the negative side, buying IP and optical layer equipment from a single vendor creates "dependencies that constrain network evolutions," according to the white paper. "Additionally, it brings a significant risk of increasing part of the OPEX, through the different upgrades and associated release qualifications since IP routers implies a high number of release updates," when compared with pure transport equipment releases.

The operators conclude that, in the case of proprietary, fully-integrated IP and optical management systems, the negatives outweigh the potential positives. The authors recommend that the industry begins working on open standards to achieve converged network management systems. This conclusion is very consistent with Heavy Reading 's findings from surveys and operator interviews during the past 18 months.

However, we continue to get pushback on this issue from various equipment vendors. A consistent counter argument we are hearing from suppliers is that, in the absence of full standards, operators will need to make proprietary decisions or lose out on the benefits of multi-layer integration completely. Granted, vendors have a strong incentive to preserve the status quo, but there is also a legitimate point being made here. With no clear cut path to standardization, how long will operators wait for multi-vendor interoperability to emerge?

— Sterling Perrin, Senior Analyst, Heavy Reading

(4)  | 
Comment  | 
Print  | 
Newest First  |  Oldest First  |  Threaded View        ADD A COMMENT
User Rank: Light Sabre
5/23/2014 | 11:55:13 AM
Re: Restoration
I think 25-30% cost savings are completely realistic in a scenario where you are just account for long-haul fiber span failures.  
User Rank: Lightning
5/23/2014 | 9:13:35 AM
Re: Restoration

Good points. As this project was entirely operator driven, it doesn't seem like there is a big incentive to make the applications appear more beneficial than they really are. The DT work I cite in my blog puts the capex savings at 24-27%, which is relatively modest compared to the 50-60% capex savings that I've seen cited in several vendor studies looking at the same application.

I'm not sure, but it's possible that the DT work takes into consideration the Internet traffic factors you've mentioned in your post. 


User Rank: Lightning
5/23/2014 | 9:04:42 AM
Full White Paper Link
For anyone interested in downloading the full operator white paper (25 pages), it can be found here:


User Rank: Light Sabre
5/22/2014 | 3:23:27 PM
You have to really investigate the cost savings associated with photonic restoration.  The reality is no one uses 1+1 optical protection and builds L3 backup capacity for "Internet" IP traffic, which makes up the bulk of traffic today.   So right there you can toss out a large percentage of the cost savings because people like to tout both being implemented in networks.  The real cost savings is in not carrying as much backup L3 capacity for Internet traffic.  If you've seen slides from vendors and operators, the paradigm of "protecting" Internet traffic is going out the window and sustaining a 2-5s outage while a link goes down and comes back up is now acceptable.

By default none of this helps you in terms of equipment failure since it assumes the majority of failures are fiber cuts, which is accurate. If a L3 port goes down, you lose the capacity.  

The landscape right now is having an orchestration system/controller which can view and manage both packet and optical domains, and forcing vendors to implement open standards for programmability.  GMPLS has been going on for 15 years now, nothing has ever come from it in terms of marrying packet and optical.  

Vendors also aren't really putting packet interfaces in transport gear or OTN/DWDM interfaces in routers either.  The density and flexibility is pretty terrible for 100G in both directions.   IMHO the real opportunity is improving the interconnect between boxes with things like MacFlex so you aren't wasting either packet or optical resources.  So if I need 40G between two sites and 320G between two sites, I'm not wasting 100G and 400G to do so.  I'm using a flexible Ethernet MAC layer and then a flexible OTN container.   

More Blogs from Heavy Lifting Analyst Notes
Huawei summit offers insights into how Asia-Pacific operators are evolving their networks for the emerging challenges of LTE, LTE-A and ultimately 5G.
Network security is becoming an ever bigger deal for communications service providers and the vendor community is reacting accordingly.
Even as MSOs roll out integrated CCAP systems, cable engineers are heating up the debate over next-gen approaches that would shift at least part of the CCAP gear and functions from the headend to the network.
With the help of NFV, cable operators can offer new managed services, roll out other services quicker, reduce their equipment load and cut operational costs.
OPNFV gets a lot of love, but it has a big job to do.
From The Founder
Steve Saunders provides an overview of white box networking and introduces a new "slim line" version of the OSI 7-layer model.
Flash Poll
Live Streaming Video
CLOUD / MANAGED SERVICES: Prepping Ethernet for the Cloud
Moderator: Ray LeMaistre Panelists: Jeremy Bye, Leonard Sheahan
Between the CEOs
Meet the Architect Behind LinkedIn

12|1|15   |   10:46   |   (0) comments

Steve Saunders speaks with Saikrishna Kotha, who leads LinkedIn's data center infrastructure architecture strategy. With over 400 million users, it's Kotha's job to deliver agility and speed, but also act as a business strategist to develop new ways that LinkedIn can monetize its user base. According to Kotha, LinkedIn runs on a mix of white box and vendor ...
Telecom Innovators Video Showcase
Service Gateway Virtual Edition

12|1|15   |   8.29   |   (1) comment

Allot's Jay Klein talks to Steve Saunders about its new Service Gateway Virtual Edition.
Wagner’s Ring
The Business Case for Open Source

11|30|15   |     |   (3) comments

Open source helps companies enhance infrastructure, undermine competitors' advantage and teach collaboration. But there are problems.
Between the CEOs
Centec on Ethernet Switching

11|26|15   |   09:58   |   (0) comments

Centec CEO James Sun talks to Steve Saunders about Ethernet switching and the white box revolution.
LRTV Custom TV
Delivering Service Agility in the Virtualization Era

11|25|15   |   5.41   |   (0) comments

Interview with Massimo Fatato, WW OSS Business Lead, Hewlett Packard Enterprise.
Wagner’s Ring
How Might Open Source Fail?

11|24|15   |     |   (10) comments

Open source, SDN, and NFV are looking inevitable – but performance, standards proliferation and regulatory capture could derail the movement.
LRTV Custom TV
NFV Lifecycle Orchestration – a Fresh Vision for Telco

11|23|15   |   6.40   |   (0) comments

Simon Osborne, CTO Comptel, and Heavy Reading's Caroline Chappell reveal the business impacts of new SDN and NFV, and what the term service orchestration actually means. Together they define Lifecycle Service Orchestration and how the virtualized future will look for telecoms operators.
Between the CEOs
Cisco's Virtual Role in Saudi

11|20|15   |   12:15   |   (2) comments

Light Reading founder and CEO Steve Saunders talks with Zayan Sadek, Regional Manager at Cisco Systems, about the competitive communications services market and advance of virtualization in Saudi Arabia.
LRTV Huawei Video Resource Center
Huawei Leads With Kubernetes for Cloud PaaS

11|19|15   |   08:26   |   (0) comments

Huawei is looking to Kubernetes as a key tool for building robust open source technologies for customers and partners, said Ying Xiong, chief architect of cloud platform at Huawei, in an interview with Light Reading West Coast Bureau Chief Mitch Wagner at the recent Kubecon conference.
Women in Comms Introduction Videos
WiC in London: The Highlight Reel

11|19|15   |   5:33   |   (1) comment

NetCracker's Mervat El Dabae headlines an inspiring morning in London with help from leading women from Vodafone, TalkTalk, Hyperoptics and Ciena.
LRTV Documentaries
Why Saudi's So Hot for New Tech

11|19|15   |   05:07   |   (0) comments

Light Reading's Steve Saunders reports from Saudi Arabia, a hyper-competitive market desperate to embrace the next generation of communications technologies and services.
LRTV Custom TV
Why Data Models Deliver More Value Than Information Models

11|19|15   |   5.08   |   (0) comments

Stefan Vallin argues that more automation is needed to manage end-to-end services and the hybrid networks they run on, and that data models are key to achieving this.
Hot Topics
Samsung: No Sale of Wireless Unit
Dan Jones, Mobile Editor, 11/25/2015
Facebook in Africa: Beauty or Beast?
Iain Morris, News Editor, 11/27/2015
Cable Gives Thanks for Business Services
Alan Breznick, Cable/Video Practice Leader, 11/27/2015
Hong Kong Moments
Ray Le Maistre, Editor-in-chief, 11/26/2015
How Amazon TV Could Own Christmas
Mari Silbey, Senior Editor, Cable/Video, 11/30/2015
Like Us on Facebook
Twitter Feed
December 15, 2015
Virtualizing Cable Services
Webinar Archive
BETWEEN THE CEOs - Executive Interviews
Steve Saunders speaks with Saikrishna Kotha, who leads LinkedIn's data center infrastructure architecture strategy. With over 400 million users, it's Kotha's job to deliver agility and speed, but also act as a business strategist to develop new ways that LinkedIn can monetize its user base. According to Kotha, LinkedIn runs on a mix of white box and vendor hardware but has the DNA of a web-scale company.
Centec CEO James Sun talks to Steve Saunders about Ethernet switching and the white box revolution.
Cats with Phones
Live Digital Audio

Broadband speeds are ramping up across Europe as the continent, at its own pace, follows North America towards a gigabit society. But there are many steps to take on the road to gigabit broadband availability and a number of technology options that can meet the various requirements of Europe’s high-speed fixed broadband network operators. During this radio show we will look at some of the catalysts for broadband network investments and examine the menu of technology options on offer, including vectoring and for copper plant evolution and the various deployment possibilities for FTTH/B.