Easy to Build: All Programmable Carrier Grade VNF Platform

Transcription

1 Easy to Build: All Programmable Carrier Grade VNF Platform INTRO: FROM VENDOR LOCK-IN TO SERVERIZED TELCO NETWORKS In an era in which Communications Service Providers (CSPs) are under increasing stress to provide an ever-growing array of services to millions of on-demand subscribers, one of the primary keys to success is flexibility. Operators are facing new demands to supply 4K video and virtual reality experiences, plus real-time connectivity for Internet of Things (IoT) applications, such that the underlying network is being heavily taxed. Gigabit (and beyond) bandwidth has become ubiquitous, but high speed alone cannot overcome the significant challenges facing CSPs. Today s telecom data networks evolved from voice-only networks and inherited their hardware-centric architectures. While speed was also important in such legacy systems, a rigid, complex network that was centered around the hardware could suffice to provide the necessary level of service. But with the changing times has come a paradigm shift, which now requires CSPs to rearchitect their networks for agility. The new network must provide a dynamic, scalable approach to service provisioning, especially for applications that demand high bandwidth and low latency. The model has transformed from the traditional, equipment-centric telecom network to a softwaredefined, flexible and programmable, cloud-based virtual data center that can be deployed and managed on-demand, enabling quick adjustments and scaling to keep up with customer requirements. This approach has necessitated a rethinking of the underlying hardware. A traditional network was comprised of expensive single-function hardware that was restricted to using the vendor s proprietary software, which could rarely interact with another vendor s equipment, leading to vendor lock-in. But a move to a cloud-based model overcomes that restriction by relying on a virtualized software-defined network to manage the traffic on top of inexpensive multi-purpose commercial off-the-shelf (COTS) servers. 1

2 Figure 1: Data centers have moved away from proprietary hardware solutions to virtualized, scale-out architectures using COTS servers. The move to COTS servers has enabled Network Function Virtualization (NFV) in the telecom industry. Virtual Network Functions (VNFs), such as virtual routers, firewalls, and load balancers, are implemented in software and can be applied as needed based on the demands at any given moment. CSPs expect to experience significant cost savings by scaling their networks with COTS-based infrastructure instead of proprietary hardware, and they gain flexibility in the process. CENTRAL OFFICE IN THE CLOUD A cloud-based approach to telecom networks, and with it NFV, has been a standard for nearly five years. Some core CSP data centers have successfully made the transition to the cloud as a necessary answer to the demand for agility and scalability. However, the Central Office (CO) at the CSP network edge, which serves as the aggregation point for traffic to and from the end user, has only recently been considered for a similar transformation. OpenNFV and the CORD (Central Office Re-Architected as a Datacenter) project have begun the process of enabling the economies of a data center and the agility of software-defined networking (SDN) by applying cloud design principles to the CO. 2

3 Figure 2: After years of applying a cloud-based approach to the core network, CSPs are now deploying a similar approach to the access networks at the edge, specifically in the Central Offices. This means a move away from proprietary edge hardware (e.g., edge routers) to COTS server arrays in the CO, which promises a more efficient supply chain for the CSP. Moreover, such a transition should lead to an increase in innovation as the industry bypasses the restrictions of proprietary systems for open environment servers with NFV and programmable logic. Another consideration is the existing geographic footprint of the carrier networks. Because of their proximity to the end users, COs represent a huge advantage to carriers over centralized data centers when it comes to latency. By replacing edge routers with COTS servers, which offer general purpose compute and the ability to run any function, CSPs increase their agility and reduce latency by moving compute closer to the access points. Beyond this agility, an additional benefit of the implementation of NFV at the edge of the network is the further reduction in CAPEX and OPEX as the network scales up and down to meet the ever-changing demands of the industry. THE IMPORTANCE OF CARRIER-GRADE ETHERNET The foundation of any CSP is its connectivity, without which there is no network, and therefore no customers (and by definition, no revenue). The standard for connectivity within the telecom industry is Carrier Ethernet, an extension of traditional Ethernet to achieve carrier-grade performance above and beyond the high standards that Ethernet already offers. 3

4 The Metro Ethernet Forum (MEF) has defined Carrier Ethernet by five attributes that distinguish it from the more familiar LAN-based Ethernet: standardized service, reliability, scalability, quality of service, and service management. Each of these aspects demands more from the services provided by CSP networks than from traditional local enterprise networks. For example, CSPs have long been held to a higher standard than many other public services when it comes to reliability. While the standard measure of scientific purity is 99.8%, CSPs have been asked to achieve five nines or % reliability, such that their services are always available to their customers. This translates into approximately 13 minutes of downtime per year, an exceedingly lofty goal for any company. Ultimately, CSPs rely on Carrier Ethernet as the lynchpin of their service offering, providing the base connectivity that defines and hosts the network and its more advanced services. All the value-added services that can be offered through CSP networks, from basic applications to IoT to virtual reality experiences, ride on that Carrier Ethernet connectivity and are useless without it. This also includes virtualized network functions such as virtual firewall (vfw) and virtual router (vrouter), which are converted from standalone components in the network to integrated elements that depend upon the Carrier Ethernet service as their foundation. Moreover, such services must be just as reliable, deterministic, and scalable as the connectivity on which they reside. Thus, ensuring carrier-grade throughout a virtual central office cloud network, and especially at the network edge, where all residential and enterprise services are merged under a single platform, is a crucial undertaking for carriers. THE CARRIER-GRADE CHALLENGE There are many considerations to take into account when implementing a Carrier Ethernet network, and this becomes even more challenging when that network is being hosted and managed in a serverized, cloud-based environment. Ultimately, if attention is paid to addressing these concerns, the cloud-based Carrier network is well-worth the effort, both in terms of performance and in terms of monetary savings. RELIABILITY Among these considerations is the aforementioned five-nines standard of reliability for carrier-grade. Traditionally, CSPs have had to implement 1+1 redundancy in their networks, pretty much end-to-end, in which there is active and backup hardware at every 4

5 step of the network path in order to accomplish such a high standard of reliability. This enables extremely fast fault recovery (less than 50 microseconds), keeping the network functioning properly at all times. However, this is also very wasteful, as there are almost constantly significant resources in the CSP network that are unused. Every switch or router that is designated as a backup exists only for the rare occasion of failure in the active component, and otherwise sits unused. There is an inordinate amount of CAPEX spent on purchasing equipment that exists in the network exclusively for the rare emergency. The move to the cloud must overcome this wastefulness, relying on load balancing across scale-out resources to ensure carrier-grade high availability at all times, while making better use of the hardware within the network. GEOGRAPHIC FOOTPRINT As CSPs convert their existing physical infrastructure on the edge, they must ensure that their CO can still convert the high bandwidth of the core to the cheaper access network without dropping packets. By using hierarchical traffic shaping at the edge, carriers can implement enough buffering to re-shape traffic to the end users at a rate that can be handled by subscriber access lines. In so doing, though, carriers must maintain cost efficiency by remaining compatible with the legacy access equipment of their end users, which tends to evolve slowly and incrementally. QUALITY OF SERVICE Carriers are often held to very strict service level agreements (SLAs) that define bandwidth, packet loss, and latency guarantees, so they have developed very sophisticated Quality of Service (QoS) mechanisms to help them keep their SLAs with enterprises. By defining several classes of service, for example to differentiate between voice, data, and video services, each of which require different levels of packet delivery, CSPs can ensure that they are providing a sufficiently positive experience for their customers so as to be in compliance with the committed SLAs. The concern is that carriers must do this with much smaller pipes than typical data centers, which are often transferring data at 100Gbps, especially at the edge. It therefore becomes much more important to monitor, test, and measure the network s performance in real-time, so it is incumbent upon Carrier Ethernet networks to provide Operations, Administration, and Management (OAM) functionality to manage QoS. 5

6 SCALABILITY Historically, carriers have scaled their networks up to account for growth, adding expensive proprietary routing hardware to an already bloated physical plant. As CSPs have embraced the design principles of cloud-based networking, a scale-out mentality has taken hold, enabling much more efficient and cost-effective approach to growth. The challenge now is to move Carrier Ethernet functionality into the COTS servers to complete the transition from scale-up to scale-out. Furthermore, because carriers must implement QoS and IP address mapping on an individual basis based on each enterprise s SLA, CSPs must scale not only their hardware, but also services as needed, which can differ greatly based on whose traffic is being carried. Therefore, carrier networks can benefit from the flexibility and dynamic nature of scalability in the cloud and must optimize their CO hardware to account for this need. At a minimum, this requires them to maintain millions of flows, with sufficient roles and counters per flow. POWER EFFICIENCY COs have existing infrastructure in a fixed footprint that defines the limits of the power and cooling that can be handled. While conceptually the Carrier Ethernet network can be run entirely through CPUs, the cost of powering and cooling such a network (at approximately 30W per CPU core) is far too great. Thus, CSPs must find a more efficient power-per-bit implementation for NFV, including Carrier Ethernet, especially in facilities with a fixed power envelope such as a CO. Similarly, with a fixed constraint of space within the COs, it is important to accelerate the available hardware to handle the same amount of functionality in less physical space. SECURITY Security is an omnipresent issue that affects all aspects of a network. Recently, though, there has developed higher demand to encrypt and decrypt data, which has traditionally been handled at the host, as it traverses the network as well. Carriers often run their data over other carrier networks, so it is critical that everything remain encrypted. Most networks use IPSec tunnels today that create and exchange security keys and encrypt/decrypt data, often at the edge of the network. 6

7 Similarly, another security function that is handled at the edge is Network Address Translation (NAT). As data is sent over a service provider s network from private IP addresses to public IP addresses, enterprises insist that their private IP addresses are not exposed. Thus, carriers must offer the mapping functions of NAT to translate addresses. Such security operations become a major consideration in the Carrier Ethernet network because they are especially computationally intensive, and therefore can adversely affect power consumption and service latency. They are also repetitive functions that must be scalable within the network according to demand. THE BEST OF BOTH WORLDS: FPGAs AS AN OPTIMAL SOLUTION TO THE CARRIER GRADE CHALLENGE To address the challenges of carrier-grade in a serverized environment, the most effective solution is to accelerate the virtualized software to produce efficiencies that overcome the issues discussed above. Hardware acceleration is a means of accomplishing more at cost; that is, the existing virtualized solution runs more efficiently, and with the same flexibility as software, therefore allowing additional functionality or significant savings on traditional operating expenses. Instead of adding more servers to the network to increase performance, which increases costs and consumes additional space and power, CSPs can accelerate existing hardware and gain similar benefits, plus add flexibility, further scalability, and reduce costs. For example, load balancing can help solve reliability issues in a carrier network, but doing so through CPUs is often costly and power-intensive. OAM functions can ensure that QoS queues are working optimally, but, again, if they are handled in CPUs, the costs are prohibitive. Scalability and power efficiency are also clear cases for accelerating hardware instead of adding CPUs. When addressing security, hardware acceleration can avoid latency penalties that are associated with compute-intensive functions that could otherwise only be solved by adding CPUs. When it comes to hardware acceleration, the logical place to focus one s attention is the Network Interface Card (NIC), as it is the hardware that is primarily responsible for data transfer. There are three primary methods of achieving hardware acceleration in the NIC: 1. Add an array of processors to the card Fixed-function proprietary processors can accelerate the networking hardware, but, in essence, this is no better than adding server CPUs. The only difference is that it is done on the NIC instead of on the motherboard. Ultimately, CPUs rely on software programmability, though, so 7

8 the gains in hardware acceleration, agility, and power consumption are negligible compared to other options. 2. Add a Network Processing Unit (NPU) to the card NPUs are cores that are highly optimized for network functions, leading to hardware acceleration. The issue here is that carriers are locked into the NPU vendor s proprietary microprocessors, and worse yet, they are locked into the vendor s toolchain for software development on that NPU. NPUs tend to be very difficult to program, and their HW acceleration is not programmable. Furthermore, NPUs have a narrow application space and do not gain the economies of scale of COTS solutions. Figure 3: Multicore and NPU solutions for hardware acceleration are limited and proprietary. 3. Add a Field-Programmable Gate Array (FPGA) to the card FPGAs are fully programmable and hardware-based, yet they are broadly applicable and are supported by general-purpose design tools for creating logic. They are standardized, non-proprietary, and multi-function, plus they offer standard interfaces to enable Software-Defined Networking (SDN). FPGAs offer deterministic performance, encourage scalability, and through their programmability enable feature enhancement and carrier-specific modifications on demand. With FPGAs, the hardware itself is programmable, so it logically follows that hardware acceleration is also programmable in that hardware. 8

9 Figure 4: FPGAs are fully programmable non-proprietary hardware with broad applications, offering flexibility, scalability, and acceleration for Carrier Ethernet networks. FPGAs are an overwhelmingly preferable option for implementing hardware acceleration to address the challenge of carrier-grade, and they are a perfect complement to COTS servers in a cloud-based CO. Since COTS servers are general purpose and agile, programmable multi-function FPGAs optimize the COTS servers ability to run all the necessary features of a carrier-grade network. In the telecom industry, no company offers more carrier domain expertise than Ethernity Networks. While other companies sell FPGAs to be plugged into a server, no one understands how to implement the logic and features that carriers need better than Ethernity. The addition of Ethernity s firmware is what ultimately makes the FPGA into a Carrier Ethernet device. Ethernity s network processing offers an advanced, feature-rich option over off-the-shelf multicore or NPU ASSPs, at an affordable price. The patented ENET architecture provides an all-around efficient design that fits perfectly into low cost FPGAs. With Ethernity, you get everything available on standard multicore ASSPs, but with the addition of full programmability, deterministic performance, and warranty to meet the required specification and features. 9

10 CARRIER ETHERNET FOR VIRTUALIZED ENVIRONMENTS While Carrier Ethernet is now ubiquitous in CSP networks, running on proprietary switches, routers, and aggregation hardware platforms, the migration of the cloud environment toward the edge, and especially into the central office for implementation of Mobile Edge Computing (MEC) via virtual Broadband Remote Servers (vbras), represents a new challenge for delivering carrier-grade while still maximizing the efficiencies that are intended through virtualization. As CSPs adapt their COs to a cloud-based approach, they must ensure that they reap all the benefits of such a move. A serverized network is pointless if the price of such a migration is the loss of carrier-grade services. The best way to guarantee Carrier Ethernet in a serverized environment is to integrate Carrier Ethernet switching and routing with data path protocol handling, while offloading data path functionality to accelerate VNFs running on the server. Moreover, combining carrier ethernet aggregation and switching with 3GPP protocol offload and load balancing will dramatically ease the deployment of MEC, which adds the benefit of offering Evolved Packet Core (EPC) closer to edge. In an era in which there is high demand for deterministic power consumption and space constraints in large server farms, such data path hardware offload can significantly reduce the required real estate and power. Combining the MEC solution with a vbras solution on one platform that utilizes traffic management and is MEF-compliant will provide operators with a compelling offering that serves both wired and mobile communication. The most reasonable way to accomplish this is through programmable hardware, that is, FPGAs on the network cards. FPGAs provide an ideal method to use COTS hardware acceleration to achieve comparable network data plane efficiency to ASICs while eliminating hardware vendor lock-in by seamlessly cooperating with COTS servers and the virtualization infrastructure and applications they host, delivering offload functionality at the speed of software development. 10

11 MULTIPLE NIC SOLUTION Ethernity has proposed a unique, innovative solution that incorporates multiple programmable FPGA ACE-NIC cards within a single server to achieve high throughput Carrier Ethernet while migrating all virtual network functions to the FPGA-accelerated hardware. Each NIC can provide 8 x 10G interfaces or various other interface designs, including 25/40/100G Ethernet and 10G PON, by utilizing an FPGA platform that enables customized interface options that buffer more than 100G toward the network while enabling the aggregation of multiple sites, cellular backhaul customers, DSLAMs, and cable systems. It would be impossible to aggregate multiple such interfaces with a traditional single-nic solution without adding external equipment. By using multiple FPGA-enabled NICs, CSPs gain the ability to connect sites directly to the server without the need for a mediation element, and perhaps most importantly, without the need for single-function proprietary hardware to handle aggregation. By using multiple ACE-NIC cards, all that is required is a simple one-to-one replacement to a COTS-based aggregation platform that offers complete programmability at both the functional and interface level. Furthermore, each FPGA NIC serves as a Carrier Ethernet switch with multiple virtual output queues representing the egress port on all other NICs, completely offloading the server and bypassing the PCIe system. For traffic that leaves the system on a different accelerator card than it arrived, the NICs perform traffic management and packet header manipulation and leverage the vswitch on the host CPU, integrated PCIe bridge, or integrated top-of-the-rack switch, to forward the frame to the right egress port based on metadata appended by the acceleration card. This offers a non-blocking platform that enables peer-to-peer switching and connectivity while maintaining QoS. For flows that require processing by a VNF, the accelerator card can prepend metadata that the vswitch will forward to the VM within which the VNF resides. The VNF can then process the flow and transmit it to the vswitch normally. Alternatively, the accelerator card can deliver the flow directly to the VNF using SR-IOV. 11

12 Figure 4: Possible flows within a multiple NIC solution for COTS servers: 1) local switching through the accelerator card; 2) virtual switching between cards; 3) VNF processing The Ethernity multiple NIC solution leverages existing cloud infrastructure to create a rich FPGA ecosystem that enables multi-vendor software applications to run on COTS Carrier Ethernet hardware, eliminating vendor lock-in. The fully programmable FPGA-based smartnics perform the high intensity Carrier Ethernet data path functions that cannot be deployed efficiently with software-only implementations, dramatically reducing latency, improving efficiency, and increasing flexibility. SUMMARY As CSPs implement a serverized approach to the edge of their networks, they will face a stiff challenge to maintain carrier-grade service at reasonable cost-efficiency. Rather than add expensive, proprietary, single-purpose hardware to overcome performance concerns, a smarter solution is to invest in hardware acceleration within the cloud-based COTS servers. The most effective method of accelerating hardware is through FPGAs on the network cards, and no one offers more expertise in such matters for CSPs than Ethernity Networks. With Ethernity s FPGA-accelerated multiple NIC solution, CSPs can leverage their cloud infrastructure to enable their virtualized environments and applications to run efficiently over Carrier Ethernet on COTS servers in the Central Offices, providing optimal performance at low cost and with ultimate flexibility. 12