by Scott Wakelin, Product Line Manager in PMC-Sierra’s Communication Products Division
Optical network operators worldwide are faced with a tremendous challenge – expanding their networks to keep up with massive traffic growth and doing so profitably.
In 2012, Cisco’s Visual Networking Index (VNI) projected network traffic would quadruple between 2011 and 2016 to 1.3 zettabytes or 1.3 trillion Gigabytes annually. Video will continue to grow and eventually consume a 55% share of network traffic. Likewise, mobile traffic will grow 18x, driven by the transition to HSPA+, LTE, and LTE-Advanced.
Market research firms project that by 2015, optical spending will increase 25% over the $12B spent in 2010 as carriers prepare to build out their metro and access networks to deal with the massive increase in Ethernet and packet traffic.
What will the new metro network look like and what capabilities will be required?
Today’s Carrier Network
In the access network, TDM services (T1/E1 private line, ISDN, voice, 2G wireless) dominated until only recently. The last few years have seen dramatic changes in the access service landscape with Ethernet replacing T1/E1 for both enterprise and mobile access. At the same time, demand for native Video and Storage Area Network (SAN) transport has accelerated, adding to the service mix that carriers must support.
- Fixed switching granularities which are only a fraction of the 10G line rate
- Inefficient support for Ethernet without the use of VCAT
- Little deployment beyond 10G and no roadmap beyond 40G
The New Metro Network
- Supports the full range of protocols that exist in the metro, including Ethernet, SONET/SDH, SAN, and Video, without the use of Circuit Emulation or Pseudo-wire emulation techniques,
- Supports efficient transport of packet services such as Ethernet
- Is able to scale to 100G and beyond,
- Offers a simple to manage Layer 1 network that extends end-to-end.
Multi-Service TransportMetro OTN provides standards-based methods to enable full bit and timing transparent transport of Ethernet (1GE, 10GE, 40GE, or 100GE) – which is critical for the growing Ethernet private line services market. In addition, OTN also supports GFP-F mapping of packet based services such as:
- MAC terminated Ethernet
Efficient Resource Utilization
- did not support this capability,
- did not support it efficiently, or
- did not support it in an interoperable manner
The new ODU0 and ODUflex containers are also switchable. Let’s explore the final aspect of Metro OTN: the support for flexible, granular and distributed OTN switching.
Flexible, Granular and Distributed OTN Switching
In comparison to muxponders, the benefits of OTN switching include:
- Efficient grooming of any sub-wavelength client onto any outgoing lambda,
- Maximum wavelength utilization
- The ability to switch an ODU from any outgoing line interface to any outgoing line interface
- The ability deploy remote management, eliminating the need for manual patching,
- Separation of client and line optic interfaces, which enables a carrier to deploy 100G wavelengths as traffic dictates
Unlike SONET/SDH, OTN imposes no limitations on switching granularity. All ODUs may be switched between any ingress and egress line card through a cell, TDM, or off-the-shelf packet fabric using the new OIF OTN over Packet Fabric format.
Silicon Impact of Metro OTNJust as the metro transport evolution is driving new requirements for OTN equipment vendors, Metro OTN also drives new requirements for silicon vendors. No longer is a simple implementation of G.709 sufficient. The following fundamental features are also required:
- Any-Service, Any-Port, Any-Rate SERDES and mappers in order to deliver true multiservice capabilities,
- High density deeply channelized OTN framing, mapping, and ODU0/ODUflex granular switching,
- High Density SONET/SDH framing, mapping and switching to enable carriers to transition from SONET/SDH to OTN without stranding their legacy network,
- Onboard Carrier Ethernet PCS and MACs with integrated packet timing capabilities in order to address the requirements of mobile backhaul in the age of LTE,
- Packet and OTN fabric interfaces to enable both packet and OTN switching applications,
- Ability to address OTN, packet and lambda switched deployments with the same device
- Multi-service, with seamless transport of Ethernet, Storage, Video, SONET/SDH, and Private Line
- Scalable with the rapid growth in packet traffic
- Switchable, providing fine-grain sub-lambda grooming
- Efficient, especially for the transport of packet centric services
- Compatible with the core network, providing end-to-end Access-Metro-Core continuity for flexibility, protection and management.
About the AuthorAs a Product Line Manager in PMC-Sierra’s Communication Products Division, Scott Wakelin has helped define some of the industry’s most successful communication semiconductor solutions including PMC’s HyPHY, TEMUX, and FREEDM product families. Currently focused on packet-optical transport solutions, Mr. Wakelin has over 12 years of experience delivering OTN, SONET/SDH, and Ethernet products to market. Mr. Wakelin holds a Master of Applied Science degree in network infrastructure and security.
About the Company
PMC (Nasdaq: PMCS) is the semiconductor innovator transforming networks that connect, move and store big data. Building on a track record of technology leadership, the company is driving innovation across storage, optical and mobile networks. PMC's highly integrated solutions increase performance and enable next-generation services to accelerate the network transformation. For more information visit www.pmcs.com.