Programmable data plane extends openflow to carrier-grade applications (ii)

Programmable data plane extends openflow to carrier-grade applications (ii) Case: Telecom Pole OpenFlow (cg-of) client implementation based on Winpath network processor

Liviu Pinchas, Tao Lang-pmc-sierra

Eddie Millsopp, Dermot Flanagan-asidua

4. Software Considerations

4.1 Data channel

To achieve the desired goal, programmable data channel devices also need to be equipped with a rich set of data channel software protocols.

The software is developed to meet the stringent real-time requirements of the carrier-class Ethernet protocol and to provide the flexibility and convenience needed to add new functionality in time as standards evolve and new requirements increase.

The available data channel software supports all the necessary standard protocols, allowing system integrators to focus on the development of high-value-added functions, such as system management of proprietary functions, thus avoiding the use of valuable resources to achieve standard functionality.

As the protocol evolves, new data channel modules have been introduced to upgrade existing systems in the field. With this approach, hardware deployment can be done even between the completion of a standardized work for a particular protocol. This is critical to accelerating new technologies like carrier-grade OpenFlow-based Sdn.

4.2 Control channel: Asidua's Wanstax product line

Asidua's Wanstax product line provides customers with a complete set of control channel software, thus accelerating the development of network services.

With the CFM ITU-T y.1731 Stack, the wanstax supports both OpenFlow 1.3.2 and OAM functions. Wanstax provides comprehensive support for MPLS-TP, OAM, and protection switching by combining Asidua's Wanstax and PMC's data channel software.

Under normal circumstances, all non-time critical PDUs associated with connection fault management and linear protection protocols are handled by Wanstax using openflowpacket_in and packet_out messages.

4.3 Integrating all components

Describes how the various components are integrated together. Existing Wanstax solutions for LP and CFM are designed as standalone solutions, so they can be executed on remote targets. The controller interface is used for the interface between the Wanstax API and the OpenFlow controller. Wanstax runs and emits API function calls, which seem to run on that target, and in fact, the OpenFlow Wanstax controller interface translates API requests into OpenFlow messages and sends them to OpenFlow switches running on the target. The OpenFlow switch decodes this message and then, through the business layer, uses these messages to configure the data channel and hardware resources to be transformed.

Non-real-time PDUs for LP and CFM continue to transmit through packet_in and packet_out messages on the OpenFlow to maintain normal operation with each other's protocols. However, time-critical operations such as CFM CCM generation, CCM fault management, DMM processing, and LP protection switching are performed by a specific logic block on the openflow switch.

Figure 4 OpenFlow Controller Interface          5. Carrier-grade OpenFlow on the Winpath architecture

The Winpath network Processor was originally designed with support for protocols that have not yet been defined. Its programmable data channels and flexible accelerator capabilities have been tested in practice and can be supported as the network evolves as the protocol is well defined.

SDN is also included in it. The Winpath is ideal for efficient and flexible openflow switches.

Figure 5 Winpath High-level function diagram

in-direction packet packets are parsed by a micro-program parser and classifier engine (PCE) at wire speed. Search for a keyword in a rule database that is stored in memory (which can be extended to an external DDR3 storage, up to millions of items). PCE does not require a large number of external tcams (i.e., high power and expensive) as many other solutions available on the market.

can have a variety of parsing operations and search behavior, not only can be used to enter the number of ports and header domain combination, but also can use the past search data.

Once this is done, packet packets plus a series of behavior based on PCE search results are passed to a set of processing units stored in a symmetric multiprocessor architecture (WINCOMM). These processor units perform data channel software to implement the various behaviors associated with packet packets, including not only discarding, forwarding to controllers, forwarding to specific ports, measuring, and more, but also more complex processing functions such as performing OAM state machines, packet packet encryption, policies, and many other functions. These actions can be performed only at the software level, or in conjunction with software and hardware accelerators.

These actions are then followed (under software control) on-chip storage or packet-packet buffering on the external DDR3 storage, tiered traffic adjustment, export policy control, and so on.

5.1 MPLS-TP OAM Example

The implementation method depicted in part IV naturally maps to the Winpath architecture.

The OAM packet is extracted from the MPLS-TP stream by the parser and the classification engine and sent to the OAM process implemented by the data channel software in the form of a state machine, and the OAM process then runs the corresponding OAM state machine, as described in y.1731 CCM.

When the line status changes, the fast protection switching process in the data channel software starts and redirects the traffic far below the 50ms requirement.

The OAM groupings are generated at a specific frequency and, with the assistance of a dedicated accelerator, are plugged into the appropriate MPLS-TP channel by the data channel software to meet stringent timing requirements such as 3.3ms interval requirements.

5.2 Winpath Series

The Winpath family of products has been provided with sufficient carrier-grade Ethernet and OpenFlow1.3.2 functions in the programmable data channel hardware and related data channel software. This complements the control channels provided in the Asidua Wanstax.

In addition, the Winpath series is also the right programmability for a simple software upgrade to move to carrier-grade Ethernet OpenFlow without delaying commercial deployment to standard or costly, time-consuming hardware upgrades. The functionality of the Winpath family of products has been proven to support software rather than new protocols in hardware cycles.

The Winpath series also includes derivative products optimized for certain access applications. Winpath3superlite mainly covers client devices and other applications with low power consumption, low device cost, and performance requirements up to 2-3gbps. The WINPATH4 includes converged applications that require higher performance (up to 40Gbps).

All of these derivative products use the same object code and feature set, allowing system vendors to use a single software development to cover a wide range of applications. PMC provides data channel code and APIs that can be produced directly, and all derivative products run the same code.

6. Advantages of Winpath architecture for operators

The implementation of any carrier-grade openflow will ultimately need to be measured by the operator. A few examples are listed in Table 1, which shows how the Winpath-based implementation mechanism helps operators achieve more efficient business allocation and network management.

Table 1 Carrier advantages and Winpath architecture

Benefits for operators	added to OpenFlow Protocol / requirements above the controller	Winpath the benefits of supporting these needs
Fast, convenient, on-demand business allocation	End-to-end bandwidth control, fast channel computing, granular SLA	Ability to implement complex SLAs based on thousands of queues that can be adjusted individually and hierarchically
Intelligent & Optimized operation	Highly efficient controller with a full range of carrier-class functions, which can be exchanged between controllers	The programmable channel does not limit or hinder the controller's function, so the efficiency of the controller can achieve the best
Virtualize IT business with NFV	Controllers with carrier-grade security and reliability features	Embedded encryption engine for security applications

The previous section of this article shows how to use Winpath in a openflow environment to achieve end-to-end OAM below 50ms protection.

Similarly, the Winpath architecture is optimized to enable all other carrier-grade features without any discounts or restrictions on the functionality of the SDN controller. The architecture of its programmable data channel can execute commands for all SDN controllers without the limitations imposed by any other solution based on the hardware implementation of the data channel. Winpath is the cornerstone of a truly interoperable solution that enables operators to select and deploy the most efficient, feature-rich, cost-effective controllers that can be upgraded without the need to be constrained by hardware devices.

Winpath's ability to implement complex SLA capabilities based on its thousands of independent, tiered-tuned queues can provide differentiated services for users. In addition, traffic shaping and regulatory parameters can be changed without losing traffic, so dynamic SLAs are implemented on a pre-defined or on-demand basis and are met in a timely manner when users need advanced business, creating additional revenue for operators. The ability to control flow parameters through OpenFlow facilitates an end-to-end implementation of such dynamic SLAs.

When applied to the client device (CPE), the Winpath can also virtualize the access routers that are typically located between the CPE and the user. All functions of the router can be migrated to the data center located in the best location in the carrier network. The data is then securely transferred from here to the CPE via an IPSec tunnel that ends in Winpath.

To provide better management capabilities and support for end-to-end Oam,winpath, all of the infrastructure required to implement synchronization on Ethernet, including the current time (ToD), is included. IEEE1588 and synchronous Ethernet are implemented on a wide range of protocols and packages, enabling operators to achieve the most desirable business and protocol without limiting their limited hardware capabilities and implementing them as the network evolves.

7. Conclusion

In order to accelerate the promotion of openflow in telecom networks, flexible solutions based on programmable data channels are needed to help operators begin system deployment before the standard is completed, or to add new functionality through software updates as requirements and actual deployment evolve.

The results of observing the demand for carrier-grade Ethernet performance, such as 3.3msCCM and 50ms protection switching requirements, clearly require several new objects, protocols, and actions to be added to the OpenFlow standard, and the forwarding plane needs to be flexible enough to accommodate these new elements. It also requires a simpler method of grouping resolution and classification to replace expensive and tcams. Therefore, the ability and flexibility of the data plane will play a decisive role in determining how these new extensions are implemented and how efficient they are.

In order to improve capex and opex, operators need to deploy Sdn,winpath's technical advantage and programmable data plane not only to solve this demand, but also to achieve real-time business updates to meet customer needs. This unique and flexible architecture enables real-time modification of complex parameters, enabling dynamic SLAs and the ability of operators to control flow parameters through OpenFlow. Today, operators have a platform for innovation that enables new network paradigms to anticipate and respond to customer needs through remote control, providing customized services and maximizing revenue.

The Winpath network processor of the PMC (www.pmcs.com) already includes all the resources needed and has a unique strategic position to support smooth evolution from existing network models to carrier-grade openflow. Asidua (www.asidua.com) Wanstax has provided the software infrastructure to support the evolution, including linear protection, CFM, and OpenFlow. This comprehensive solution provides a complete package for operators wishing to deploy MPLS-TP and other carrier-class features with OpenFlow.

Programmable data plane extends openflow to carrier-grade applications (ii)