When Business Success Depends on Network Access: 3Com Solutions Deliver Continuous Application Availability
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Business Challenges
Not so long ago, only a few industries depended for their day-to-day survival on the reliability and uptime of their data networks. It was easy to see that if the network went down—or even slowed down—in a bank or stock exchange, a hospital or medical center, or an automated manufacturing operation, the results could be catastrophic: lost revenues, lost credibility, even lost lives. Businesses in these industries invested heavily in secure data centers, redundant high-speed backbones, emergency networking spares, remote backup facilities, and other measures to guarantee "high availability" networking. Other businesses were content to spend just enough for a basic LAN that worked well most of the time. But things have changed. Today, nearly every business has come to rely on services and applications that run on the office LAN. Now, a network outage is not just an inconvenience. Almost every business system, from interoffice communications, to customer service, to procurement, to time tracking and billing—sometimes even the storefront itself—relies on the network in some way. If that network goes down, the results can be disastrous. And since most companies have limited IT staff, there may not be a skilled person available who can rush to the scene to get the network up again quickly. Consider the following cases.
Maintaining the Trust of Customers and Business Partners
CONTENTS Business Challenges........................................1 Maintaining the Trust of Customers and Business Partners .......................................1 Managing Data and Large Files..................1 Ensuring Application Access with Limited IT Staff.......................................................2 Keeping Billing Systems Online ..................2 Showcasing Products Around the Clock ...................................................2 How 3Com Addresses the Availability Challenges ....................................2 Network Access: Getting to the Network Anytime, From Anywhere.................3 Application Availability: Clustering Servers and Fine-tuning Application Performance .......3 Network Availability: Building a Fail-proof Infrastructure ..................................4 Device Availability ......................................4 Network Level Availability ..........................5 Implementing Network Availability Using 3Com XRN Technology.....................6 Proactive Network Management.....................6 Conclusion .....................................................8
A manufacturer of parts for the construction industry has an e-commerce web site where it displays its product line and receives orders. In addition to its retail business, the company is also a supplier to several large manufacturing operations, which place their orders electronically on the e-commerce site as part of their just-intime manufacturing processes. Once placed, orders are transmitted over the company’s LAN to an inventory and production scheduling system, which confirms availability of the ordered items and guarantees a ship date. If the LAN is down, the company’s orders cannot be confirmed or processed. Retail buyers move on to another vendor’s site; wholesale customers place the orders with a more reliable preferred supplier. Not only does the company lose the order, but the trust of its customers as well.
Managing Data and Large Files
A commercial publisher serves a metropolitan area with a full range of services from design and pre-press through printing and distribution. For each job, multiple employees in different departments must access large graphics files many megabytes in size. At one time, these files had to be copied to floppy disks or laboriously burned onto CDs for transfer from one graphics workstation to another. Today, all files are stored on LAN servers and accessed over the company’s Gigabit Ethernet backbone. The LAN saves the company time and money in a very competitive and deadline driven industry. But if the LAN goes down, even for a few hours, the business stops in its tracks. The press schedule is disrupted, deadlines are missed, and customers are unhappy.
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Ensuring Application Access with Limited IT Staff Showcasing Products Around the Clock
Computers are a central element in an ambitious program designed to bring an urban school district’s student achievement into line with state and federal standards. The district received a grant to equip classrooms from kindergarten through high school with computers, and to train teachers in innovative ways to incorporate educational software into their math, science, and social studies teaching. The computers at each school site are networked together, and in addition to educational applications, the network supports administrative services, including e-mail, food service, attendance tracking, and accounting. Suddenly, the school LAN is at the center of the district’s academic agenda. Lesson plans are built around computer access, and if the network goes down, irreplaceable learning opportunities are lost, putting at risk the success of the students and the computer learning program. But the grant doesn’t include funding to put an IT staff person at every school site. In fact, a small team of IT specialists must serve the entire district.
Keeping Billing Systems Online
Few industries are more competitive than residential real estate, and few have been more affected by the Internet. Today, potential home buyers use the web at any time of the day or night to browse the web sites of any of a dozen realty agencies in their target location and view listings, learn about neighborhood schools and amenities, and take video tours of listed homes. Agents in the realty office use LAN-based systems to access the wealth of tools and resources they use to serve their clients. But in this business, the window of opportunity is often brief and delays can be costly. If the agency’s web site is unavailable due to server problems at the office—even at midnight— prospective buyers can easily move on to another realtor’s site. And if the office LAN is sluggish or server-based applications are unavailable when it’s time to prepare an offer, the buyer’s dream home may be snapped up by another agent’s client.
How 3Com Addresses the Availability Challenges
Continuing its tradition of innovation, 3Com now brings easy-to-use, cost-effective solutions for LAN availability within the reach of every business. Companies no longer have to spend a fortune or double their IT staff to ensure that their essential business systems are continuously available to users who need them. Uninterrupted availability of computing resources on the LAN hinges on four key elements: • Network access • Application availability • Network availability • Proactive network management This paper introduces each of these aspects of network availability and describes how 3Com solutions help today’s companies keep their essential business applications up and running cost-effectively.
A growing law firm has recently adopted a popular legal software solution to streamline and automate its business operations. Now, case management, status and deadline tracking, calendaring, and document production and management are handled over the firm’s LAN. Perhaps most importantly, the platform provides integrated time billing, accounting, and management reporting for the entire firm. An easy-to-use Windows interface lets attorneys enter time and billing information on their desktop PCs or laptops. But if the LAN goes down, the attorneys lose their connection to the server where the application, the client data, and the billing system reside. They can’t report their time to the firm’s billing system, and valuable billing data may even be lost.
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Network Access: Getting to the Network Anytime, From Anywhere
Until fairly recently, it was only workers in certain departments who really needed to be logged onto the network all day. Most employees could sign on every few hours to check their email or retrieve a file from a server archive. The rest of the day, and after hours, they could count on their voice mail to bring them most of the important information they needed to be productive. And most of their key applications were stored on their desktop hard drive. The typical workplace today is dramatically different than it was even a few years ago. The electronic revolution has infiltrated the way people work, sometimes without them even realizing it. Today, most workers log onto the office network the minute they walk into their offices, and stay connected all day, handling a continuous stream of emails and working with business-critical applications that either reside on a server or depend on data housed on a server across the LAN. And many workers also log on to their office networks from their home PCs— in the evening or on telework days—or remotely using a wide range of mobile computing devices from laptops to personal digital assistants (PDAs) to a new generation of cell phones. In response, today’s LANs must support new access capabilities, and in new ways. They must be secure as never before in order to protect users and intellectual capital through enhanced authentication, encryption, and control. To achieve this, 3Com switches support robust authentication using standards-based (IEEE 802.1X) RADIUS-based network login throughout its product lines, including on its chassis-based Switch 7700 and on the stackable edge SuperStack 3 Switch 4400 family. Additionally, access control lists (ACLs) on key Layer 3 switches—Switch 7700 and Switch 40x0— enable network managers to control access to certain network segments or resources on the network.
Networks must also adopt new ways of ‘pushing’ content to users, finding better ways to distribute immediate and relevant information to workers who need it, wherever they may be and in whatever format their computing device requires. Whether a user is across the room or across the world, using a PC or a cell phone, the network should be able to find them, identify them, and give them access to the information they need. And in addition to sharing data applications, users will increasingly need their networks to support integrated voice, video, and data, provide a single messaging system for voice mail, email, and fax.
Application Availability: Fine-tuning Application Performance
Application availability has traditionally focused on server performance and availability. Today, the characteristics of high availability servers—resiliency, redundancy, and manageability—still need to be addressed, but improvements in new areas such as network traffic optimization through application prioritization can help optimize the performance of application access. 3Com switches, such as the SuperStack 3 Switch 4400, Switch 7700 and Switch 8800, support end-to end intelligence to classify and prioritize traffic from specified individuals or applications across the network. Classification schemes identify applications via socket number, protocol, IP address, port number, or DiffServ Code Point. Techniques like Quality of Service (QoS) and IEEE 802.1p provide a standard for assigning each packet a priority level. Switches support traffic queues that give preference to high priority traffic, ensuring faster transmission for a Class of Service (CoS) system. Application prioritization ensures that a video training session or executive briefing won’t be interrupted by a large backup file transfer, and that voice applications on the IP network, such as the 3Com® SuperStack® 3 NBX® Solution, will deliver the quality phone communications that users expect.
3Com® SuperStack 3® Switch 7700 family
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Network Availability: Building a Fail-proof Infrastructure
Network availability traditionally measured the uptime of database servers in corporate IS departments or of reservation systems for airlines. Today the definition is broader, covering a wide range of e-business applications, including e-mail, and taking into account the availability of the network resources needed to access those applications. In e-business applications, especially in converged networks of voice, video, and data, poor performance—resulting in unacceptable transmission quality, information loss, and dropped connections—may be just as costly as hard failure.
3Com SuperStack 3 Switch 3870, with resilient stacking (back view)
For large enterprise core switching, high availability is a top requirement. The 3Com Switch 8800 modular switch delivers resiliency through a combination of resilient switch fabrics, hot swappable redundant power supplies and cooling fans, and network interface modules. The Switch 8800 design allows for dual active/active load-sharing fabrics, so adding resiliency also doubles the performance of the switch, making maximum use of this investment. Standards support, such as IEEE 802.1w Rapid Spanning Tree, further increase the resiliency of the network. The Switch 7700 is ideal for small campus core and distribution and edge switching. Its modular design supports similar levels of chassis resiliency, with an available resilient fabric for the largest (7-slot) configuration. To eliminate the need to reset a system during replacement of a failed module, all configuration changes can be performed online and all modules can be added or replaced without shutting down or rebooting the switch. (This is commonly called "hot swap" capability.) All configuration information is maintained in the Management Module(s). When a failed I/O module is replaced by another of the same type, the Management System will automatically restore the previous configuration. This speeds the replacement process and avoids costly configuration errors. With redundant switch fabrics, the second switch fabric routinely mirrors all activites and configuration parameters of the primary fabric, including address databases, spanning tree paths, and virtual LAN (VLAN) memberships, Meanwhile, a three-way judging system queries the health of both fabrics with run-time diagnostics every 100 milliseconds. If the primary fabric fails, the system software automatically cuts over to the redundant module in less than a second, ensuring seamless operation. Typically, users have no idea that a change has occurred in the network.
In order to support today’s increasingly demanding applications, network availability must be 99.99 percent or even 99.999 percent—the famed "five nines". This level of availability used to be expensive and complex to configure, maintain, and support. But through technology innovation, 3Com now offers simple, affordable solutions that deliver the high levels of availability essential for most LANs. To ensure maximum fault tolerance, uptime, and application availability across a network infrastructure, companies must concern themselves with both device availability and network level availability.
Device Availability
3Com Switch 8800 family
Device availability is the ability of an active network component to resist failures. This starts long before the system is installed at a customer site. During the design stage, emphasis is placed on using high quality components with exacting tolerances. Network core products should use advanced ASIC components that provide the highest levels of reliability, and should be designed with redundant architectures to safeguard against any failure in power, performance, or control.
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Resilient stacking is supported by both the 3Com SuperStack 3 Switch 3870 and Switch 4400 families. Units can be connected together to form a "stack" to scale the number of ports in a location while enjoying single-IP management. With resilient stacking, a connection to a single switch can be broken and the remaining devices in the stack will continue to function as a single managed switch.
Network Level Availability
Trunking and IEEE 802.3ad (LACP) Link Aggregation. Trunking is a Layer 2 feature
Starting with high quality, well-designed active network equipment, it is now possible to design highly available network configurations. Technologies used to provide network level availability in 3Com products include link redundancy and protocol and router redundancy.
3Com SuperStack 3 Switch 40x0 family
Link redundancy is implemented by designing multiple paths across the network infrastructure to ensure re-routing of traffic across alternate paths in the event of failure. Link redundancy can be implemented on 3Com products using the following technologies:
Resilient links. Resilient
which allows multiple physi-cal links between two switches to be combined into a single virtual link. Depending on the capabilities of the various switches, a number of links can be combined, providing a significant increase in performance. Both the 10/100-based SuperStack 3 Switch 4400 and the 10/100/1000-based SuperStack 3 Switch 3870 stackable switches support LACP trunking, including trunked ports that span multiple units in a "stack" of units. If one link fails, the load is redistributed between the remaining links, providing con-tinuous operation. For added peace of mind, with trunked ports on different units, the failure or removal of a unit will not bring down a full trunk. Although some initial configuration is needed to establish trunks, the failover is completely automatic. Trunking has been standardized by the IEEE 802.3ad committee under the name Link Aggregation. Protocol and router redundancy applies primarily to network infrastructures deploying Layer 3 switching. It allows the design of multiple logical and routed paths across the network, ensuring that routed traffic is redistributed appropriately in the event of a failure. Protocol and router redundancy is implemented on 3Com switches using the following technologies:
Open Shortest Path First (OSPF). OSPF is the
Links is a unique feature available on 3Com network interface cards (NICs) and switches. It operates at the physical interface level and depends on the detection of hardware link failures. The Resilient Links feature allows almost instantaneous switchover to a second link in case of failure. This method is very simple and does not require any protocol or configuration.
Spanning Tree and Rapid Spanning Tree Protocol (STP and RSTP). The Spanning Tree
3Com SuperStack 3 Switch 4900 family
standard allows multiple paths to be created across a network for redundancy without creating loops, which could permit the same packet to be delivered twice. In case of the failure of a link, the protocol redirects traffic across other links to allow continuous operation. All 3Com switches support standards-based IEEE 802.1D Spanning Tree Protocol and the newer IEEE 802.1w Rapid Spanning Tree Protocol. With the latter, network failover times for a downed link is less than 5 seconds.
most widely used Layer 3 protocol. It allows the routing of TCP/IP packets across both the LAN and the WAN. The OSPF protocol uses specialized packets to determine the topology of the network. In case of a router failure, it attempts to re-create paths from all sources to all destinations.
Virtual Router Redundancy Protocol (VRRP).
VRRP is an industry standard defined by the International Electrotechnical Commission (IEC) which allows redundant router paths. It defines a primary router which functions as the default gateway for attached IP end stations. In case of failure of the primary router, the secondary router takes its place.
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Implementing Network Availability Using 3Com XRN™ Technology
In addition to the traditional ways of implementing network level availability, 3Com’s XRN (eXpandable Resilient Networking) technology can also be used to design highperformance, highly available core backbones that offer link redundancy and protocol and router redundancy. With XRN technology, multiple interconnected Gigabit switches behave as a Distributed Fabric—from both a Layer 2 and a Layer 3 switching perspective—that grows with the network, without the physical limitations of a centralized core device.
3Com SuperStack 3 Switch 4400 family
Proactive Network Management
Possibly the most critical single factor in network availability is the ease of network management. Network management is the manager’s window into the vital ingredients of high availability; it is the means for measuring, fine-tuning, and reporting on the success—or failure—of any network availability initiative. Network management works by giving IT and network managers powerful tools for identifying applications, servers, network devices, and other key resources, and for measuring usage of these resources. 3Com® Network Supervisor, the company’s management software application, begins by discovering all the devices and links on the network and making an initial (baseline) measurement of the state of the network. Once baseline performance is measured, the network manager can then set thresholds for monitoring performance. The data center switches should have strong basic features such as controls for baselining, threshold setting, and event/alarm monitoring that alerts the IT staff to any events in the network. Today, sophisticated management software agents are available in 3Com switches to perform analysis and report back through Simple Network Management Protocol (SNMP) to 3Com Network Director or other 3Com management applications.
All XRN-capable switches, such as the 3Com Switch 4060, or members of the SuperStack 3 Switch 4900 family, support wire-speed switching and routing using 3Com’s highperformance custom application specific integrated circuits (ASICs). Support for Link Aggregation across the Distributed Fabric (Distributed Link Aggregation) increases both performance and availability. Distributed Resilient Routing technology also provides high-performance routing across the interconnected switches, enabling router redundancy for the core backbone. 3Com’s XRN technology represents an innovative new choice in network design for application and network availability. Active/active resiliency, in which resilient switches or fabrics share the load to improve overall performance, is carried into the chassisbased Switch 8800 where its resilient fabrics double the performance of the switch.
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FIGURE 1: 3Com Switch 8800s at the core of the network help provide continuous availbility
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Network management systems that help maintain high availability should have the following characteristics:
Ease of configuration and control. The network management system should make it possible for the network manager to determine and modify device configurations, check device status and generally manage devices—all remotely, from the management console. These systems can also make it much easier for network managers to configure advanced features such as traffic prioritization on SuperStack 3 Switch 4400s across the network. Identify potential problems before they happen. The system should be able to idenMonitoring application usage. The
network manager should be able to monitor network usage using real-time and historical data displays, perform packet analysis, and monitor traffic to see where bottlenecks—or potential bottlenecks—exist. These network management capabilities make it possible to implement centralized, standardized network operations policies. After taking baseline measurements, the network manager can move to application and network health monitoring. With these in place, the network can be fine-tuned by setting traffic prioritization, security, configuration, and monitoring controls centrally, according to the company’s business objectives.
tify potential misconfigurations and optimization during the initial network discovery operation, thus saving time troubleshooting the network later. Similarly the system should be able to identify changes in the network configuration since the last discovery operation.
Network health monitoring. This higher-level network management functionality should give the network manager enterprise-wide views of overall network health; it should allow for checking status priorities, setting thresholds for action-on-event operations, and reporting fault data in real time. Radically simple network troubleshooting.
Conclusion
3Com helps today's companies keep their essential business applications up and running with solutions that are simple and affordable, bringing the highest level of networking availability within reach of every business. 3Com networking solutions ensure network access, maximize application and network availability, and provide proactive network management, ensuring that a network slowdown or outage does not interfere with business operations. To build high availability into their core networks, 3Com customers can select one of the modular 3Com Switch 8800 or 3Com Switch 7700 configurations, which support a range of resiliency and availability features for uninterrupted operation and unmatched performance. For distribution switch deployments, consider 3Com's unique XRN technology for creating a resilient scalable switching environment from two 3Com Layer 3 switches, such as the SuperStack 3 Switch 4900 or Switch 40x0. At the edge of the network, consider the SuperStack 3 Switch 3870 for Gigabit-to-thedesktop installations and the SuperStack 3 Switch 4400 for 10/100 networking.
The network management system should make it as easy as possible to pinpoint problem areas as quickly as possible. Key features in this area include the ability to trace traffic across the network and to get the status of each individual device and link so that the network manager can identify the problem area very quickly. 3Com Network Supervisor also provides the capability to correlate events, so that only the problem which caused the network fault (such as a major link going down) is reported, not all the resulting device not available events which would clog up the event log.
3Com Corporation, Corporate Headquarters, 350 Campus Drive, Marlborough, MA 01752-3064 To learn more about 3Com solutions, visit www.3com.com. 3Com is publicly traded on NASDAQ under the symbol COMS.
The information contained in this document represents the current view of 3Com Corporation on the issues discussed as of the date of publication. Because 3Com must respond to changing market conditions, this paper should not be interpreted to be a commitment on the part of 3Com, and 3Com cannot guarantee the accuracy of any information presented after the date of publication. This document is for informational purposes only; 3Com makes no warranties, express or implied, in this document. Copyright © 2004 3Com Corporation. All rights reserved. 3Com, the 3Com logo, NBX, and SuperStack are registered trademarks of 3Com Corporation. Exercise Choice is a trademark of 3Com Corporation. All other company and product names may be trademarks of their respective companies. While every effort is made to ensure the information given is accurate, 3Com does not accept liability for any errors or mistakes which may arise. Specifications and other information in this document may be subject to change without notice. 503112-003 10/04