MSAN:

 

Building Scalable, Highspeed Cost-Efficient Multi Service Access Node Line Cards

 

Telecommunications Equipment Manufactures (TEMs) are facing tough challenges in their triple play concentration and distribution equipment including MSANs. While there are multiple media options to deliver this type of service each media requires a different type of networking component that may handle the required protocols and throughput. This much-talked-about dedicated engineering resources for each media type , which result in huge expenses associated with each media including ADSL,VDSL, Fiber, PON, Transport, Mobile Backhaul and wireless. This type of equipment must now be designed with significantly more bandwidth to support non blocking IPTV , additional protocol handling, traffic management to deliver high QoS, Ethernet and MPLS OAM, Synchronous Ethernet , Content distribution and more stringent multicast performance to support the current IPTV requirements and the future Internet video and appliance including gaming, video and voice conferencing

 

Another major challenge is being able to offer everything for less.

 

Increasing bandwidth requirement results with the design of Next Generation Access Node where based on 10G/40G dual star architecture that requires dual 10G/40G link towards the backplane. The dollar per port price Telco’s will pay for DSL cards has fallen precipitously in recent years, and is not going to change when migrating to ultra high-speed Next Generation Access Platforms. In the face of falling prices, the challenge is to maintain same Access Node platform that can serve G.vector VDSL cards together with Highend Mobile Backhaul GbE , WDM or PON access line cards.

 

A third challenge faced by TEMs is the endless need to come up with support for new application , protocol and support the evolving market needs with the need to create a platform that can support new requirements and interfaces without the need to wait for specific silicon implementation, and control the release of the Next Generation Access Node releases. The equipment vendor will choose to build its solution based on platform that will enable him to differentiate his solution, by enabling fast responds to evolving market needs through the use of Field Programmable Device.

 

Next Generation Access Aggregation Line Card Processing Requirements

 

There are a number of features that the ideal Access Processor (AP) must possess to address the challenges discuss above and to meet the demands of next-generation MSAN’s.

 

Throughput: It is critical that the Access Processor have the throughput necessary to enable non blocking performance to all media and ports connected on specific line termination module , and to a newer 10G/40G dual star backplanes to deliver new revenue generating services and to enforce the QoS contracted with all customers. Throughput should be deterministic and not vary based on the type of network traffic internal processing functionality. The Access Processor must allow bandwidth to be flexibly partitioned based on port, service, and direction, all with low line card cost and low power. As the video services portion of the triple play is deployed, the need for throughput and access processor performance in the MSAN line card increases perhaps by an order of magnitude. Not only due to the fact that each port needs to provide more throughput , but the nature of triple play services is to duplicate video stream on the line card for the required ports that register to specific service. No longer can DSL aggregation bandwidth be so largely oversubscribed. The demands of video streams are too large and too constant to allow the level of over-subscription tolerated in pure data services DSL deployments. The Introducing of GbE access for mobile backhaul, and acceptance of PON FTTx application introduce a minimum of 100Gbps processing needs for MSAN line cards. The throughput of an Access Processor lacking deterministic performance must be measured based on its worst-case performance to assure committed service rates are not impacted when handling “tortuous” protocols.

 

Flexibility: The ultimate Access Processor will have the exact interface and packet processing capabilities needed for the line card it is designed into. Since it is common for Access Equipment vendors to have a family of line cards for their platform(s), the ideal Access Processor must be available as either a family of devices or as a device with flexible interfaces. If the AP has too many interfaces trying to meet the needs of all, then the line card design will be burdened with additional board area, cost and power needed to support unneeded functionality. Worse, if the AP does not have sufficient interfaces to meet needs, then it either cannot be used or will require additional external devices or logic to compensate for this shortcoming.

 

An Access Processor should also be capable of supporting the full range of protocols today including  Tagged Ethernet, SNAP, Q-in-Q, MAC-in-MAC,  MPLS-TP, PPPoE, LACP and must have the flexibility to easily handle additional not yet defined protocols in the future

 

Scalability: While sufficient throughput is needed for high-speed and high port count line cards, a solution that can scale down in price (including external memory), power, and board area is needed for other line cards. System vendors gain product lifecycle efficiencies by using the same technology, components, and suppliers across a wide range of products. AP’s must have the scalability and flexibility to fit in products covering a range of performance and applications.System vendors are looking for a generic interworking and traffic manager solution that can scale for ADSL through VDSL , Ethernet and PONs, which increases OEM scalability and helps reduce carrier CAPEX and improve OPEX .

 

Enabling Universal Line Termination Processing

 

The ENET - the first commercially available Ultra low cost FPGA Access Flow Processor—is enabled by unique architecture that enables the use of low cost FPGA with a combination of low cost DDR2/DDR3 Memory to provide advanced functionality and flexibility and compete with Packet Processor and Network Processors with better functionality, performance and cost. The ENET Family is implemented in FPGA to support up to 40Gbps, and soon a 100Gbps will be avilable based on same software.

 

Ethernity’s ENET leverages a paradigm shift in ASIC development that enables complex and high-volume designs to cost effectively go to production in FPGA’s. The move to 28 nm process technologies and soon to 16nm and the associated large increase in mask costs and development costs have left only the highest volume applications able to afford the investment required to justify moving a design into the leading edge process. Today FPGAs are implemented in 28nm process technology ( 16nm in 2014) and offers the logic density, speed, power, and cost advantages associated with this leading edge process technology.

 

Ethernity’s Virtual ASSP solution is enabled by the ENET’s highly efficient architecture and by recent advances offering low-cost, high-density FPGA’s. The ENET handles classification, framing, packet editing, inverse multiplexing, switching , routing ,forwarding, and all traffic management. These functions are handled by a number of pipelined atomic engines. The ENET architecture is very efficient with respect to the amount of logic required for the device: One 8th the number of gates is needed relative to what is found in a typical RISC Access NPU. This gate or logic efficient architecture combined with advanced FPGA technologies has enabled a low-cost FPGA High end 12Gbps Access Processor solution and 40Gbps solution .

 

Providing reconfigurable modularity to the access processor architecture essentially redefines broadband access line card design and deployment flexibility, scalability and cost savings. The Access Flow Processor provides multiple line interface types and reprogrammable interworking options on a single, modular architecture. Interchanable line interface units offer a cost effective way to add service interface types and customize line cards - precisely to the port count and packet processing line card demands. Why not get exactly the line interface you need, per port, instead of having to build separate line cards? Reconfigurable, build-as-you-need-it deployments can substantially reduce capital costs. The ability to add incremental bandwidth accommodates unpredictable growth and changing traffic patterns, and eliminates costly unused ports

 

In fixed line card architecture, the need for different port counts & service types forces the TEM to develop multiple line card designs based on different packet processors which increases initial costs and creates bandwidth specific solutions. Inflexibility also increases total cost of ownership because it multiples the number of development teams and limits cross-platform scalability.

 

In contrast, the ability to address multiple service types and port counts with a single reconfigurable access packet processor architecture substantially lowers overall system cost and provides a scalable bandwidth independent solution. Flexible line interface options and protocol interworking functions can enhance network performance, evolution and multiple-service convergence while reducing operational complexity and expenses. Going forward, the Access Flow Processor unique capabilities enables flexible access line card design and scalability to simplify future growth, as described in the below diagram implemtned by ENET

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conclusion

 

We began with a review of the requirements of Access Processors for MSAN line cards. Next, we saw how combining Ethernity Networks efficient ENET architecture with FPGA’s created a family of products tailored to the needs of Telecom Aggregation and interworking platforms. Ethernity’s ENET Access Flow Processors have the best combination of performance, feature set, flexibility, and price available.