DEVELOPING A STRATEGIC APPROACH TO DATA CENTER NETWORKING

Transcription

1 DEVELOPING A STRATEGIC APPROACH TO DATA CENTER NETWORKING Executive Summary Data center networking presents many challenges in terms of supporting cost-effective, reliable, and high-performance services for business-critical applications. A coherent overall strategy for networking, leading to construction of a powerful and flexible network, creates more long-term value than a series of tactical, project-oriented steps. many discrete circuits implemented on a tactical, per-application basis, resulting in inefficient bandwidth utilization, poor management visibility, and extra bandwidth expense. Business demands on the network continue to multiply as a result of: Approximately 60 percent annual storage growth and corresponding data protection requirements Ciena advocates a strategic approach to deploying high-performance, business-critical applications across Metro and Wide Area Networks (MANs and WANs). Ciena s solutions offer improvements over tactical WAN optimization or FCIP systems by addressing the heart of the problem: the need for a high-performance, deterministic, manageable, and cost-efficient network. Data Center Networking Challenges Every organization supports a wide variety of requirements from worldwide access to data to emerging mobility applications with a different data center environment for computing, storage, and networking. Recently, news outlets have reported that many top organizations such as Microsoft, Google, Yahoo!, NSA, Lowe s, and Intuit are seeking to take advantage of new data center designs for green initiatives to improve energy and cooling efficiencies, space utilization, and networking. Additional reasons that organizations are changing data center footprints and physical locations include: Approximately 46 percent compounded growth in IP traffic over the next four years The need for improved real-time information access from multiple worldwide locations Requirements for rapid deployment of new high-bandwidth applications These demands can stress infrastructure architectures and budgets, necessitating a new strategic approach to setting technical requirements for the data center network. Mission-critical applications require predictable Quality of Service (QoS) delivered with low latency and high bandwidth. In addition, end-to-end management visibility and flexibility are important for a variety of client interfaces and applications. Bandwidth consolidation and improved bandwidth effectiveness can save costs. Business growth, internally or through acquisitions The need to save costs through data center consolidation Relocation to a geographic area offering improved costs for land, power, and water Implementation of multiple sites for business continuity and disaster recovery The networking infrastructure supporting the data center enables applications such as storage services across the MAN or WAN. Sometimes the network technology selected stretches between multiple data centers for hundreds or thousands of miles. Many enterprises also need to make multiple new and legacy applications and technologies coexist. Over time, the data center MAN/WAN architecture may have evolved to include W Whitepaper Global Network Figure 1. Data center networks Bandwidth Alternatives Enterprises today have an expanding selection of bandwidth solution alternatives involving carrier services, on-site premises equipment, and network connectivity. Choosing the most effective bandwidth solution involves

2 Data Center Environment Servers Disk Storage Switch LAN Switch VOIP Video Storage Figure 2. Bandwidth options Bandwidth Options Fiber Carrier Network SONET/SDH Router ATM Frame Relay Leased Line Edge Applications GEO Clustering Channel Extension Remote Remote Disk Mirroring Extension FCIP Gateway LAN Extension Voice over IP Video Transport many logistical factors and a good understanding of the application s performance requirements. Network security, path independence, and redundancy are all important design considerations and cost tradeoffs. Traditional SONET/SDH services are being replaced with new, more flexible metro Wavelength Division Multiplexing (WDM) and Carrier services, a shift that throws optical fiber-based bandwidth solutions into transition. WDM is being deployed either as a private optical network or obtained from carriers as a wavelength managed service. Enterprise data centers connected with WDM networks have the highest scalable performance and lowest latency, deterministic connectivity, and security. WDM networks also can lower bandwidth operating costs by consolidating data paths and simplifying the networking infrastructure. Newer Carrier services are replacing private lines for data center networking in the form of Private Line (E-Line) and transparent LAN (E-LAN) services. This range of services offers compelling value propositions for scalability, cost effectiveness, and automated fast provisioning using s common data link layer. E-Line services can match the service rate to the actual data rate more effectively than traditional private lines and reduce network complexity and operating expenses. Since standard does not provide lossless data transport, it does not meet the requirements for data center convergence. A set of 802.x standards are being developed under the umbrella term Converged Enhanced (CEE) or Data Center (DCE) to provide standards for lossless data, congestion management, priority-based flow control and other capabilities to support storage data traffic. Also supporting the convergence trend, Fibre Channel over (FCoE) is being developed as an ANSI T11 (FC- BB-5) specification for an encapsulation protocol for transporting Fibre Channel over or CEE. These emerging standards will enable converging, Fibre Channel and InfiniBand protocols on a single adapter card and consolidating the networking and cabling systems. An IP network is another widely deployed bandwidth option that can be obtained from carriers or more often in large companies deployed with a switch/router network. The ubiquity of Internet access and client LAN traffic has driven the growth of IP networks. Today, new bandwidth-intensive applications such as storage networking, VoIP, and video are driving strong enterprise bandwidth demand and causing IP traffic surges and congestion. Edge routers accept fast Gigabit (GbE) client inputs from the LAN, but still have T1, DS-3 or SONET/SDH connectivity over the WAN, which could create a speed mismatch somewhere in the router network and result in a traffic bottleneck. For example, some storage networking systems support jumbo packets to provide better frame-matching between Fibre Channel and, but engineering support for jumbo frames throughout the IP network is difficult. As a result, the storage traffic in these systems is not as efficient as possible, and the extra IP storage packets could generate more congestion. Traditional bandwidth services such as DS-3, ATM, and Frame Relay are widely available, but fall short in their ability to scale capacity cost-effectively for today s high-bandwidth data center networking applications. Storage Networking Applications Drive Bandwidth Requirements Data mirroring or replication applications provide a redundant data copy in a secondary location. Generally, synchronous replication occurs on the most mission-critical data sets, while asynchronous copy with some data loss exposure typically occurs on class 2 and 3 data sets. Storage networks and transport systems are sized by how much data needs to be transferred in a specific time. An enterprise-class, multi-terabyte Storage Area Network () environment might have many controllers and switches to support replication, backup, and file transfer using multiple Fibre Channel interfaces and multiple Gigabits of bandwidth, as illustrated in Figure 3. A recent Forrester Consulting report on disaster recovery showed that over 65 percent of organizations had more than 50 TB of data to protect. For example, a data center might have 70 TB of storage, where 10 percent of the data is estimated to change each day and therefore must be 2

3 Connectivity Requirement WAN Optimization IP Gateways Enterprise Networking WDM Gb/s (e.g., s FC/ FICON/) s Gb/s (e.g., ~ 25+ FC/FICON) replication Remote tape Large s replication vaulting Bandwidth aggregation Synchronous replication Server Clustering (GDPS) Multi-services Gb/s (e.g., 5-20 FC) 1-15 Gb/s (e.g., 1-15 GbE) Server-based replication replication Storage controller w/ WAN IP Enterprise IP SONET/SDH Carrier OTN Figure 3. Data center network scalability replicated for protection. This amount of data traffic is transmitted most efficiently over a WDM Optical Transport Network (OTN) that can multiplex multiple 2.5 or 10 Gb/s wavelengths. An OTU-1 network at approximately 2.5 Gb/s can transmit approximately 7 TB in an eight-hour day (calculated at 80 percent bandwidth utilization). applications over the WAN. This technique called Wide Area File System (WAFS), Wide Area Application Services (WAAS), application acceleration, or protocol optimization allows applications (such as Word documents) to perform as well over a 1,000 mile network as they would from local storage. In contrast, a smaller storage environment using serverbased or Network Attached Storage () replication might be accommodated easily with a 1GbE connection into a TCP/IP or Multi-Protocol Label Switching (MPLS) network edge router with a DS-3 45 Mb/s WAN connection. This network would allow approximately 130 GB to be transferred in an eight-hour day a transfer rate that could fit a 1.3 TB storage environment. Clearly, different networking strategies are dictated by whether the network will need to transfer multiple terabytes or gigabytes. WAN Optimization Fit Data applications using the IP network also consume data center bandwidth. A growing number of remote applications like ERP/CRM, , and SharePoint increase IP network traffic and the potential for congestion, dropped packets, increased latency, and other problems. WAN optimization originally was designed to improve communications between a branch office and a home office data center, as illustrated in Figure 4. WAN optimization controllers help improve remote application access by reducing the latency delays associated with chatty Data Center A Switch This optimization enables organizations to save costs by consolidating and centralizing storage and computing resources. More recently, WAN optimizers have been deployed to enhance the performance of storage replication and file transfers between data centers. Increased use of file transfer storage applications over IP drove requirements for additional technology like data compression, so effective bandwidth became a multiple of Figure 4. Branch office networking Packet Delay Variation (jitter) Network Latency Packet loss Bandwidth QoS Branch Office Data Center B Files, Financial, Database Switch iscsi 3

4 Figure 5. Ciena s WDM platforms FC FICON WDM over dark fiber the actual bandwidth. As more and more applications started to drive IP network congestion, new traffic-shaping and network integrity features were implemented for a differentiated QoS between different applications. More recent tools for caching and de-duplication are designed to avoid sending redundant data across the network, improving data transfer performance. Some WAN optimizer companies also support application acceleration and caching techniques for storage replication over the IP network between data centers. All WAN optimization systems are designed with inputs and outputs that limit their overall scalability and enterprise deployment for storage networking. WAN optimizers cannot accept direct channel connections from a Fibre Channel switch or storage controller a major differentiator from storage networking systems that drive much higher data throughput rates by having channel inputs with larger data frames at two, four, or eight times GbE speed, and correspondingly much faster network ports using SONET/SDH or WDM technology. Ciena s Data Center Networking for the MAN using WDM Ciena advocates a more strategic approach to deploying high-performance, business-critical applications across MAN and WAN networks. Ciena offers improvements over tactical WAN optimization by addressing the heart of the problem: the need for a high-performance, deterministic, manageable, and affordable network. Ciena addresses the root cause of network congestion and inefficiencies with platforms that minimize latency and maximize bandwidth utilization. Ciena provides networking platforms for multiple applications with direct storage channel and network inputs to 10 Gb/s that efficiently map traffic onto optical networks. Multiple channel and LAN inputs can be aggregated over MAN or WAN links. Bandwidth transparency and efficiency virtualize the network s capacity to reduce the number of discrete circuits required for independent systems and provide a platform for a lower-total-cost solution. Ciena s WDM Platforms 6500 Packet-Optical Platform and 4200 and 5200 Advanced Services Platforms Bandwidth solutions based on optical fiber support business continuity and disaster recovery applications by providing ideal transport for storage networking between data centers. For metro distances where fiber is available, Ciena s WDM platforms provide the ultimate flexibility for channel and LAN data center networking. Ciena s WDM platforms offer multiple module options to implement the appropriate client protocols and speeds, with a corresponding network output of multiple 2.5G or 10G wavelengths and beyond to 40G and 100G. In addition, storage networks typically transfer businesscritical application data requiring redundant configurations that are difficult and costly to implement using multiple WAN optimization devices. Many replication networks require synchronous transfer to eliminate data loss, which is not supported on WAN optimizers. Client support includes ESCON 200 Mb/s and FICON 4/8G channels, Fibre Channel at 4/8G or 10G, and 1GbE or 10GbE. Ciena s WDM platforms support IBM s GDPS, With these limitations, WAN optimization is a tactical solution that fits branch office application acceleration requirements and some low-end storage applications, but addresses only a small portion of overall enterprise requirements for data center networking. Figure 6. Options using 4200 with FC FICON } SONET/SDH OC-12,48; STM-4,16 GbE Layer 3 SCTP/IP Layer 1/2 Carrier E-Line, E-LAN 4200 w/ Carrier Network 4

5 Data Center A Data Center B Files, Financial, Database Carrier Managed Service FC FICON Switch Fibre Channel iscsi Data Center C Figure 7. Ciena Carrier Managed Service network a complex server clustering and business continuity solution designed to maintain time synchronization between mainframe servers, manage remote copy storage, automate parallel processing operational tasks, and perform failure recovery from a single point of control. The 4200 and 5200 also can transport video signals supporting content acquisition, post-production, and forward-distribution applications using the Serial Digital Interface (HD/SD-SDI, 3G-SDI on 5200) for high and standard definition, and the Digital Video Broadcast (DVB) digital television standards using the Asynchronous Serial Interface (ASI). Ciena s FlexiPort technology enhances the physical ports by enabling deployment of new services simply by re-programming a port. This capability reduces costs by decreasing the need for maintenance, spare hardware, and management. Ciena s Data Center Networking for the WAN using Carrier and IP When storage networking over IP was introduced in the late 1990s, new technologies were developed to enable missioncritical storage traffic to flow reliably over IP networks that were architected primarily for and Web page traffic. Storage traffic for tape backup or disk replication tends to be more constant, at a high throughput rate, than smaller bursts of or Web traffic. As a result, new standards were developed, including FCIP for Fibre Channel tunneling, ifcp for an independent - routed connection, and iscsi for IP encapsulation of SCSI storage commands. Similar to the WAN optimizers, these techniques require extra features, which often create other limitations and tradeoffs, to deal with the inefficiencies of TCP re-transmissions across the network caused by packet loss. To better support data center networking over over Carrier and IP WANs, Ciena has implemented Stream Control Transmission Protocol (SCTP/IP) to replace TCP as the transport layer protocol. SCTP is better suited to storage traffic over IP because it ensures reliable, in-sequence transport of data with optimized congestion control; is inherently well-suited to long fat pipe transport; and is multi-streamed for optimized parallel transport session support. Ciena leverages these properties to support protocol-independent, high-performance networking over IP WANs and most particularly over Carrier services. SCTP differs from UDP and TCP transport layers primarily by enabling multiple data transmission streams and supporting multiple IP addresses for multi-homing support. These capabilities allow redundant and alternate data paths to be set up for full resiliency in the event of one path failure. SCTP enables Ciena s IP solution to offer improved security, with 32-bit checksum support, high reliability, and increased availability. Key advantages of Ciena s SCTP implementation include data flow improvements for failover, guaranteed delivery, path selection, and error detection all vital to storage traffic. 5

6 Data Center A Data Center B Files, Financial, Database FC FICON WDM over dark fiber Switch Fibre Channel iscsi Data Center C Data Center X Figure 8. Ciena enterprise data center network 4200 with Enterprise Services Optimization Module Ciena s Services Optimization Module () supports data center networking over Carrier and IP WANs, as shown in Figure 6. The card fits into any 4200 chassis: 2-slot 4200 MC, 5-slot 4200, or 17-slot 4200 RS. The card accepts two client inputs of Fibre Channel, FICON, or GbE, and multiple cards can exist in each chassis. Similar to the CN 2000 Storage and LAN Extension Platform (see Appendix), these protocols are efficiently mapped directly onto SONET/SDH. supports both data compression and dynamic bandwidth assignment to provide a port-level QoS to 2 virtual connections. Unlike WAN optimizers without channel inputs, the 4200 also enables direct channel connections to all Carrier and Layer 3 IP network and services using the SCTP/IP protocol. SCTP at the transport layer provides in-sequence data transport with congestion control and supports multiple transmission streams and multiple IP addresses for better throughput, redundancy, and resiliency. In addition, the use of six-port EM6 modules enables 20-port /EM6 configuration in a four-card set, 14-port configuration in a three-card set, or eight-port configuration in a two-card set. and EM6 are part of the 4200 platform, working either standalone or in conjunction with other 4200 modules to enable deployment of comprehensive data center networking solutions. Ciena s Strategic Approach to Data Center Networking Ciena enables enterprises to implement a multiservice strategic network that is flexible and programmable. Enterprises can choose the network configuration and implementation that best suit not only immediate project requirements, but also add up to strategic assets. These network components can be obtained from Ciena carrier partners as a managed service, as shown in Figure 7, or implemented directly by the enterprise as a private network, as shown in Figure 8. A managed service enables accounting for the service as an operational expense, saving capital expense outlays and costs associated with purchasing and maintaining the equipment. A private network gives the enterprise the ability to implement a strategic platform for current and expected needs, with the flexibility to handle unexpected new requirements. Enterprises can start a strategic approach to data center networking by assessing overall bandwidth and growth requirements, then implement the network architecture with the Ciena platform for data center networking performance that matches company requirements. The Ciena solution allows enterprises to take advantage of the right bandwidth option for the job and look for opportunities to consolidate discrete circuits. Although IP is not the only choice for networking over the WAN, Ciena s unique solution ties into the overall strategic network. Carrier networks also provide new solutions for the enterprise. 6

7 Networks built with Ciena s platforms provide a superior solution for data center networking over the MAN and the WAN. Next Step Contact Ciena for additional information on flexible networking solutions for data center networking over WDM MANs, and Carrier or IP WANS. Appendix FC ESCON FICON Fibre Channel DS-3 SONET/SDH OC-3,12,48, STM-1,4,16 GbE L1/2 CN 2000 The CN 2000 provides an eight-port client aggregation and bandwidth management solution for applications using storage channels and. The client traffic is mapped efficiently directly onto the SONET/SDH, DS-3, or GbE Layer 1/2 network. This technique eliminates the need for the data traffic to go through multiple systems and for more protocol layering that would reduce performance by adding system and protocol latency. Figure 9. Unified data center network Optical Metro 5130 The OM 5130 provides FC and GbE client networking over DS3 and OC-3 with the added capabilities for IP networking and encryption. The OM 5130 is an ideal all-in-one encryption appliance for storage networking to lower the cost of securing data in transit across the WAN. With data compression and application-level QoS using dynamic bandwidth assignment, the CN 2000 provides a compact footprint solution, offering economical, effective bandwidth for data center networking. This solution fits either a metro (<120 miles/200 km) or wide area distance topography. 7

8 Glossary ATM CEE Asynchronous Transfer Mode; cell-based telecommunications protocol for data traffic developed in the 1980s Driven by 10G-and-above, Converged Enhanced describes a set of standards for an enhanced lossless that supports not only traditional LAN but also Fibre Channel and Infiniband channel I/O. Also known as Data Center (DCE) DS-3/E3 A Digital Signal circuit operating at 44.7 Mb/s, internationally known as E3 at 34 Mb/s DVB-ASI Digital Video Broadcast Asynchronous Serial Interface; a suite of international digital television standards; ASI defines the physical layer device interaction E-Line A Carrier service for private line, virtual private line, or Internet access delivered in 10/100/1000 Mb/s or 10G; Carrier services are defined by standards from multiple organizations like the Metro Forum (MEF), IEEE and ITU-T E-LAN A Carrier service for multipoint Layer 2 VPNs or a transparent LAN service, also defined by MEF EPL ESCON FC FCoE FCIP FICON GbE Private Line, a Carrier service to replace a TDM private line Enterprise Systems Connection, IBM s channel I/O for mainframes operating at 17 Mb/s, with a maximum data rate of 200 Mb/s, introduced in 1990 Fibre Channel, a multi-gigabit network for storage I/O operating at 1, 2, 4 and 8 Gb/s, with future standards to 16 Gb/s Fibre Channel over (FCoE or FCoCEE) an ANSI T11 (FC-BB-5 project) specification for an encapsulation protocol for transporting Fibre Channel over or CEE Fibre Channel over IP, a tunneling technology to connect s over IP Fiber Connectivity, IBM s channel I/O for mainframes operating at 1, 2, 4 and 8 Gb/s, introduced in 1999, similar to Fibre Channel but with unique I/O commands Gigabit IETF ifcp iscsi LAN MAN WAN SCTP SDI Internet Engineering Task Force, standards setting body for TCP/IP Internet Fibre Channel Protocol, a gateway standard for routing Fibre Channel over IP to independently interconnect s Internet SCSI protocol, encapsulates block I/O SCSI commands over IP Local Area Network, typically 10/100/1000 Mb/s Metropolitan Area Networks; typically denotes a regional < 120 miles, 200 km distance Wide Area Networks; typically a distance greater than 120 miles, 200 km Storage Area Network, implemented as a block I/O network fabric using switches or directors that support Fibre Channel, FICON, and iscsi Stream Control Transmission Protocol, a transport layer protocol replacing TCP to ensure reliable, in-sequence transfer of message frames Serial Digital Interface High Definition (HD), Standard Definition (SD), family of broadcastgrade video interfaces; HD-SDI has a nominal data rate of Gb/s SONET/ Synchronous Optical Networking/Synchronous SDH Digital Hierarchy, a digital multiplexing hierarchy for transferring data over optical fiber T1/E1 VoIP WAFS WDM A Time Division Multiplexed (TDM) data circuit operating at Mb/s, internationally known as E1 at 2.0 Mb/s Voice over Internet Protocol, delivery of voice over the Internet Wide Area File Services, products that enable remote file access at LAN performance; also known as Wide Area Application Services (WAAS) Wavelength Division Multiplexing, technology that multiplexes multiple optical signal (wavelengths) on a single optical fiber; Coarse Wavelength Division Multiplexing (CWDM) multiplexes at a specified channel spacing grid, enabling less expensive optical components; Dense Wavelength Division Multiplexing (DWDM) implements closer spacing of the wavelengths for higher number of channels per system Ciena may from time to time make changes to the products or specifications contained herein without notice Ciena Corporation. All rights reserved. WP064A Networks that change the way you compete Winterson Road Linthicum, MD (US and Canada) (outside US and Canada) (international)