Routed Optical Networking(RON): Ice breaking technology to converge today’s IP and Optical Network
Service providers are exploring approaches to meet changing market conditions, including rising operational costs and increasingly flat revenue. Concurrently, they are facing challenges in addressing the exponential traffic growth on their networks. Drastic traffic growth continues — from video, gaming, and virtual and augmented reality, as well as from the introduction of 5G and future technologies. The majority of the services consuming this increased capacity are also causing lower Average Revenue Per User (ARPU) and higher operational costs for service providers as they build and upgrade network infrastructure to scale and support the capacity growing at an exponential rate.
Complex legacy network transformations require tightly integrated networks that can scale with the future demands of high bandwidth including video streaming, low latency, and coverage densification. The Routed Optical Networking (RON) solution can enable scale by converging mobile and fixed, voice and private line traffic onto a single converged internet protocol (IP) and optical network.
RON Technology: Cisco’s innovation of converged IP and Optical network
Section 1: Coherent optical pluggable modules are key to the economics of convergence
1.1: What is Coherent Transmission?
In simple terms, Coherent Transmission is a system that combines amplitude modulation, phase modulation, and polarization to transmit greater amounts of information through a fiber optic cable than is possible with simple on-off keying. Using digital signal processing at both the transmitter and receiver, coherent optics also offers higher bit-rates, greater degrees of flexibility, simpler photonic line systems, and better optical performance.
1.2 What is Coherent Optical pluggable modules/Transceivers?
A coherent optical module refers to a typically hot-pluggable coherent optical transceiver that uses coherent modulation and is normally used in high-bandwidth data communications applications.
Optical modules characteristically have an electrical interface on the side that connects to the inside of the system, and an optical interface on the side that connects to the outside world through a fiber optic cable.
Coherent optical modules plug directly into the router line cards.
Coherent detection moving deeper into the network: optical internet working forum zero return (OIF ZR) specification for <120km and OpenZR+ for >120 km reach.
1.1.3:Why is the transport economics important?
The optical transceiver is one of the most important elements in datacenters. Currently, QSFP28 transceiver module is the leading product in the market that supports 100 gigabit Ethernet applications. However, the market continues to evolve with the emergence of new bandwidth-hungry applications. The 400G QSFP-DD optical module is being positioned to efficiently address this need for higher capacity in the metro.
Section 2: Challenges with today’s network
Today’s networks are layered, siloed and complex making automation/management/scaling difficult. Legacy networks maintain separate layers for optical transmission and IP routing.
2.1: SP networks are multilayered and siloed
Traditional network architectures comprised networking layers that relied on line cards for service hand-off between the layers. Services terminate at different layers of the network. Each layer provides redundant functions, management, and control. This kind of layered architecture is highly inefficient as it consumes too much line card CAPEX resources and relies on manual operation for service hand-off between the layers.
2.2: Control and management
Moreover, each networking layer has its own control and management plane associated with it which operates independently from each other.
This complexity negatively impacts service assurance, fault correlation, path optimization in terms of network utilization, as well as network planning and optimization. These complexities present challenges to SPs’ aspirations towards achieving service driven end-to-end, closed-loop automation across the entire network infrastructure.
2.3: Total cost of ownership (TCO)
TCO associated with legacy network architecture is prohibitively high and will not allow SPs to scale their network to meet the capacity demands of IP services in a cost-efficient manner.
Section 3: Road to Solution
The solution is to build a converged optical + IP network.
3.1: Architectural Change is required
3.1.1: Road to Solution-1: Integrate Transponders with Routers
3.1.2: Road to Solution-2: Integrate OTN Services
3.1.3: Road to Solution-3: Integrate ROADM
3.1.4:Road to Solution-4: Build converged SDN transport
3.2: How the converged architecture moves towards solution?
3.2.1.Coherent pluggable module
As router port densities increase, the CAPEX spend transitions from the line card ports to the pluggable optics.
3.2.2. Line rate scaling
It is is achieved with 400GE line rate. The critical enabler for the scale envisioned for the future CSP network is the 400GbE line rate.
3.2.3. Multi-vendor, standardized and preserves port density
Quad small form-factor pluggable (QSFP) double-density (DD) module allows interoperability for easier adoption and benefits of scale. The compact size of QSFP-DD pluggable module offers 400G line rate scalability while preserving the port size in the router.
3.2.4. 400G QSFP-DD optical modules go the distance
QSFP-DD can provide transport to the mobile edge (20 km), regional datacenters (40 km) and central datacenters (80 km and and above). 400GE pluggable coherent optics will become ubiquitous in networks by 2022. And with OpenZR+, distances of 1500km are possible.
3.2.5.Hop-by-hop (H2H) is the future of transport
H2H routed network architecture will replace traditional multi-layered “hollow-core” architecture.
Section 4: How E2E RON solution works?
Routed Optical Networking within the Converged SDN Transport framework transitions networks from the siloed infrastructure to a new architecture that relies on a single control plane based on IP/MPLS in a converged hop-to-hop IP and optical network. This drives significant simplification and cost savings. It addresses the complexities and redundant networking layers that present bottlenecks to scalability and enables end-to-end automation in the communication service provider network infrastructure through:
● Assimilation of any Time-Division Multiplexing (TDM) and wavelength services into Private Line Emulation circuits to ensure against latency and improve resiliency of high revenue services
● Direct integration of high capacity optical interfaces (coherent) directly on the routing devices without density penalties that existed in IP over Dense Wavelength-Division Multiplexing (IPoDWDM)
● Full hop-to-hop IP routing architecture characterized by a single networking/switching layer in the IP domain and simple point-to-point optical infrastructure with or without the cost and complexity of Colorless Directionless Contentionless (CDC) Reconfigurable Optical Add-Drop Multiplexers (ROADMs)
● Single, routed optical networking across IP/routing and optical transport infrastructure for:
-Unified capacity and network planning
-Path optimization
-Service assurance, inventory and element management
Routed Optical Networking offers a simplified architecture that integrates with OSS and automation tools for reduced operational complexity. The result is a single network infrastructure that can be planned, designed, implemented, and operated as a single entity through network automation.
Network automation can also help with optimized utilization of fiber capacity, so providers get more out of their fiber assets. Segment Routing Path Computation Elements (SR-PCE) and other network orchestration or path optimization tools can be used to ensure maximum utilization on existing capacity to lower the instance of overbuilding the network.
Section 5: What advantages RON technology is going to offer?
Conclusion
The converged transport network fueled by RON technology, will enable unprecedented dynamic data capacity. service agility, efficient utilization, better protection, lower complexity and reduced TCO. Such a network drastically improves resiliency and availability as well. The RON technology is especially for the next-generation network traffic that is dominantly and natively packet-based.
RON is the game changing and ice breaking technology that will change the though process of Telco people to transform the legacy IP/Optical network structure and enter the new paradigm of 5G era. I have no doubt of that. Cisco is the Pioneer to bring the new concept of technology in front the door of Telco people.
Thanks to Cisco and expecting to get update of more and more innovations.
Thank you!!
Monowar Hossain
HOD, Microwave Unit (Planning & Operation)
VEON, Bangladesh
E-mail:monowar.hossain@banglalink.net
Mobile: +8801962424691
Originally published at https://www.linkedin.com.
