Maximizing WAN-Based Citrix Deployments and Applications

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1 White Paper Maximizing WAN-Based Citrix Deployments and Applications Build Smarter Networks

2 Table of Contents 1. Executive Summary Overview of the Problem Elfiq and Citrix Desktop Virtualization Web Application Delivery Netscaler Branch Office Application Delivery Conclusion Elfiq Networks. All rights reserved 2

3 1. Executive Summary Application, virtualization and Web services have evolved significantly in the past five years to the point that organizations are migrating traditional infrastructure resources such as desktop applications to virtualized environments, and server applications are being succeeded by Web-based services. When making such infrastructure changes, it is common practice to implement new technologies to deliver the expected value, and Citrix is a common technology vendor for such projects because of its content and application delivery expertise. 2. Overview of the Problem WAN-based applications are being regularly used to replace locally based applications and servers for mobile workforces, satellite offices and business partners. In such a computing paradigm, the natural congestion point and strategic point of failure is Internet access at both head office and branch locations. Considering that most organizations in 2010 still depend on a single carrier approach to deliver bandwidth to their sites, a part of the value proposition can easily be in peril. When building the systems and infrastructure for such deployments, it is common to make systems redundant with duplicated components such as servers, storage, power management and networking infrastructure and even to set up disaster recovery/business continuity sites, but the topic of bandwidth redundancy remains neglected. Single carrier implementations philosophically go against the idea of maximum uptime by leaving a stone unturned in the overall plan, which may prove critical. Beyond carrier access availability, bandwidth is in high demand due to the changes occurring in the nature of Web-driven content, where rich media is gaining ground in internal networks and applications, mimicking public Web sites such as Facebook and YouTube for content delivery and internal group productivity. Datacenter consolidations will also increase bandwidth usage especially on virtual private networks (VPNs) as resources are no longer hosted on local servers Elfiq Networks. All rights reserved 3

4 The following metrics outline what organizations are experiencing with their carrier services: Elfiq Networks customer survey: technology failure rate experienced within 12 months (2009): 2 Elfiq Networks customer survey: number of carrier failures within 12 months (2009): 2 Infonetics Research monthly downtime expectations (2006): 1 Average hard downtime per month 1.7 outages Average duration per hard downtime Average hard downtime per year 67 minutes 23 hours Average percentage of employees affected 28% 2010 Elfiq Networks. All rights reserved 4

5 3. Elfiq Networks and Citrix Recognizing the need for maximum uptime and improved performance, Elfiq Networks achieved Citrix iready status in Elfiq is the only Link Balancer manufacturer to obtain this recognition by collaborating with Citrix, and it is the only vendor certified on the Branch Repeater product line (formerly WANScaler). 4. Desktop Virtualization Strategy Desktop virtualization is a topic of growing interest and is being adopted in IT departments to cut user management and PC management costs. This technology is being utilized with both users on the corporate network as well with remote users, providing always-on access to desktop operating systems and/or virtualized applications. The commonly used products in the Citrix portfolio are XenDesktop, XenApp, Citrix Access Gateway and the Receiver and Dazzle products, which connect users to business applications through any PC including their home PC and mobile devices such as the Blackberry, the iphone and Windows Mobile devices. Using the Citrix Access Gateway and Xen products, some organizations have successfully replaced existing VPN implementations for mobile users, thus simplifying access and cutting operating costs for supporting users. As these virtualized application delivery mechanisms are adopted and deployed, bandwidth will be taxed for incremental throughput as bottlenecks appear at peak business times, and reliance on its reliability will increase. The introduction of carrier services will provide a significant benefit for daily usage, and link balancing appliances will add significant value to both IT teams and users through key capabilities: - Bring incremental ISP carrier links into the organization without the need to redesign the WAN part for throughput and failover capabilities. - Balance inbound traffic across multiple carriers seamlessly based on policies, link status and availability to ensure optimal access to resources Elfiq Networks. All rights reserved 5

6 - Introduce low-cost carrier links to complement existing ISPs to segment traffic such as HTTP/S onto asymmetrical links for internal users and allocate symmetrical links to Citrix-based applications - Geographically balance traffic across multiple datacenters and/or at disaster recovery sites should the primary site be unavailable. 5. Web Application Delivery Strategy The explosion of Web-driven applications in the past few years has created a new level of requirement for uptime and performance because when one of these two metrics is down, business transactions will suffer directly. To deal with this situation, organizations have deployed server load balancing appliances such as Citrix s Netscaler to manage multiple servers for content and transaction delivery. In this context, ISP carrier availability and saturation become critical elements of a successful implementation, and Link Balancers make it possible to meet and exceed goals set by management as well as customer expectations. One of Elfiq Networks customers, Radialpoint ( uses both Elfiq products combined with a server load balancing solution to deliver its value to its customers, where over 40 million DNS requests are handled daily through Elfiq appliances for security update downloads Elfiq Networks. All rights reserved 6

7 In this context, the Link Balancer deployed can deliver the following benefits to a Netscaler implementation: - Bring incremental ISP carrier links into the organization without the need to redesign the WAN part for throughput and failover capabilities. - Balance inbound traffic across multiple carriers seamlessly based on policies, link status and availability to ensure optimal access to resources. - Geographically balance traffic across multiple datacenters and/or at disaster recovery sites should the primary site be unavailable. This is complementary to the Netscaler GSLB function as carriers are balanced, not servers. - Make GSLB connections resilient through the use of multiple concurrent ISPs for maximum uptime. Should a carrier link fail in the example below, the GSLB link will continue uninterrupted as the GSLB traffic is redirected to another carrier without Netscaler being aware of or involved in the process. The Link Balancers will redirect traffic as per defined policies. 6. Branch Repeater Strategy The Branch Repeater product line (formerly WANScaler) enables organizations to significantly accelerate transactions running over WAN connections to LAN-like performance. Elfiq Networks Link Balancer is currently the only product that is iready certified for this platform (/citrix). A case study on this type of deployment is available at /victrix Elfiq Networks. All rights reserved 7

8 The Link Balancer appliance will add resilience and increased performance to Branch Repeater projects by multiplexing carriers for the VPN tunnel used for this application. By combining multiple carriers seamlessly, which requires no changes to the WAN devices, the Link Balancer appliances control the flow of traffic between two endpoints, selecting which carrier is the best choice for either direction. When the links used are of similar speed and throughput, these carrier links can be bonded, creating a larger virtual tunnel from smaller components. Should a carrier link fail, the VPN (and Branch Repeater) traffic will be automatically and transparently redirected to another carrier without breaking the active sessions, leaving transactions unaltered and without the need to restart them, From a performance perspective, each Link Balancer will be exchanging carrier link information to determine which path from left to right and right to left is the most appropriate at any given time, so traffic will always be optimally handled to avoid bottlenecks and provide a performance boost to the Branch Repeater deployment. 7. Conclusion For organizations with an investment in Citrix deployments, these applications have become critical to delivering their value propositions to their customers, as well as the tools and resources their employees need to perform their tasks. Due to the high demand of Internet-based transactions and traffic for both customers and employees, this has become a critical point of failure. Link Balancers can alleviate this point of failure by using multiple concurrent ISP carriers seamlessly, so bandwidth is available for all requests and a failover process is introduced to guarantee that at least one carrier is available to deliver the data while the other(s) is (are) being brought back to active capacity. Organizations using the Xen, Netscaler or Branch Repeater products will immediately benefit from such an approach Elfiq Networks. All rights reserved 8

9 Produced by Elfiq Networks Elfiq Networks is a technology leader and innovator in the field of WAN link management and balancing. With successful installations in over 60 countries, Elfiq s Link Balancer products help organizations of any type and size perform more competitively every day with the ability to use multiple Internet and private links easily and securely. For more information on Elfiq Networks products and technologies, please contact: Elfiq Networks 1155 University, #712 Montreal, Quebec, H3B 3A7 Canada Telephone: 888-GO-ELFIQ / Internet: info@elfiq.com References: 1: The Costs of Downtime: North American Medium Businesses 2006, Infonetics Research, March : Elfiq 2009 Customer Survey February 2010 Copyright 2010, Elfiq Networks (Elfiq Inc.). The contents of this document are protected by copyright. Any modification of this document, in any shape or form, is prohibited. Any redistribution, publication or derivation of the contents of this document without written authorization from Elfiq is also prohibited. All rights reserved Elfiq Networks. All rights reserved 9