Optical NetworkingTraditional WDM solutions are limited by the technology used to add and drop wavelengths at each site. Capacity planning poses a challenge to anyone attempting to build an optical network by using fixed-channel filters (Figure 1), which can only add and drop specific channels or bands of wavelengths.
Changes to traffic patterns must be engineered in advance, and in-service changes require inserting new filters into the network, disrupting service and affecting users.
A reconfigurable optical network offers the possibility of growing services between sites with no advanced engineering or planning, and without disrupting services.
What Problems Need to be Solved?
In the past, reconfigurable optical networking technology was too expensive or delicate to be widely deployed. With newly developed silicon-based integrated Planar Lightwave Circuit components, reconfigurable optical add/drop multiplexers (ROADMs) are now being installed in many applications.
Reconfigurable Optical Networks
The Cisco ONS 15454 Multiservice Transport Platform (MSTP) offers a comprehensive reconfigurable optical networking solution, including:
- 40-channel ROADMs available in C and L bands
- Multi-rate tunable transponders and muxponders that can support any service, including Ethernet, TDM, and storage
- Intelligent WDM software that can automatically manage and adjust optical power levels as new services are added or deleted
- Engineering tools to rapidly solve network design requirements and simplify network installation
- Optical components capable of supporting 40-Gbps signals for future growth
- Software that can offer end-to-end management of wavelengths, including signals that originate from devices such as routers and Ethernet switches
Compared with the fixed-filter design, the ROADM design shown in Figure 2 allows any wavelength to be dropped at any site without affecting any of the other services.
What are the Benefits of a Reconfigurable Optical Network?
The use of reconfigurable optical networking technology provides several benefits to both service providers and business users. These include:
- In-service growth from 1 to 32 protected wavelengths without affecting existing traffic
- Simplified network design and provisioning and lower operational expenses
- Faster service installation and provisioning
- Superior management visibility into the network for lower operational cost, including per-channel power levels as seen in the figure below
Cisco has achieved tremendous success with its optical multiservice platforms, with more than 50,000 ONS15454s deployed to date. Only Cisco can provide an end-to-end optical transport solution which combines MEF-certified Ethernet, TDM, and reconfigurable DWDM service delivery that can also meet the stringent IP service level agreements needed for low-latency data services such as IPTV.