subject: Considerations for selecting the right WAN acceleration solution [print this page] Considerations for selecting the right WAN acceleration solution When considering optimizing overall application response times and bandwidth throughput, there are a few considerations that need to be taken into effect. This section reviews and addresses the common requirements to make a more efficient and effective choice regardless of the solution providers mentioned in this study. Through this document we will describe different ways in which we will compare the different solution and decide on what key factors are needed in choosing the right WAN Optimization solution within an infrastructure. Deployment and Administration One of the significant factors generally involves deployment and administration time. In order to keep these factors to an optimal low, we need to consider a solution that predominantly requires easy setup and configuration. The solution must be easy to configure and provide management tools that allow large to mid size deployment across an infrastructure. The solution; Must support automated device discovery and a management system allowing administrators to easily troubleshoot issues in the event of failure or when the system is offline. Must provide easy configuration through a web or application console. Must provide troubleshooting tools and troubleshooting information. Should handle configuration upgrades to multiple devices at pre-scheduled time. Must support inline and must not require any routing changes. Be scalable to bandwidth upgrades, not limited to the original stat of the initial configuration. Must provide a tunnel visibility capability allowing application monitoring products to see the original application port numbers within the tunnels and maintain the integrity of those tools. The device must support pre-filtering in order to allow specific applications to transparently pass through the appliance. Bandwidth and Connectivity WAN optimization solutions rely on WAN links, it is important to understand which types of WAN attributes a solution supports. Some solutions need T1 connectivity, while others work over an ordinary Internet connection. By evaluating the level of bandwidth needed to support each remote office, WAN optimization features can help mitigate bandwidth requirements. It's also useful to evaluate the supported transports, such as (MPLS), IP VPN, or other supported transports to ensure that the product is fully compatible with the infrastructure. The solutions; Must be able to continuously measure link latency and packet loss. Must support complete recovery from packet loss at the remote site without requiring retransmission from the local site. Should be able to define separate policies on a per link basis. Supported Applications and Protocols A wide range of enterprise applications are supported by most WAN optimization solutions. Part of the consideration for most companies would be to verify that the product evaluated supports the applications or file types used within the environment. Manageability In order to provide reliable manageability over a network a set of features must provide sufficient information on every networked device that is connected to the network. A WAN optimization solution should include the industry accepted fault, configuration, performance, and security management capabilities. Data Reduction Percentage Data Reduction Bytes Packet Reduction Before / After Throughput Before After Burst Throughput Packet size distribution Total percent of traffic by application Data reduction by application Able to filter traffic by application Able to define custom applications by TCP/UDP port number(s), IP protocol, HTTP URLs,
Deep application inspection Must support the ability to analyze traffic flows through the device Must be able to separate view of reduced traffic and pass through traffic Must be able to summarize based on IP address or application port number Must be able to run this capability constantly with no perceived overhead or performance degradation Must be able to report on the latency across an optimised WAN link as well as any packet loss. Configuration by Class Fault Management Reduction Tunnel up/down WAN Link up/down LAN Link up/down Scalability One important criterion is the level of scalability that an appliance can provide on the WAN. More importantly is how much throughput that the appliance can actually support with the relevant and desired optimization functions turned on. Other aspects of scalability include how many simultaneous TCP connections the appliance can support and how many branches or users a vendors complete solution can support. For throughput and connection optimization, the appliance must support all branch office sizes, data centers and mobile clients through application acceleration as well. The appliance must be able to support high number connections and optimize a high number of traffic. TCP Acceleration Most solutions are designed to support a given protocol (for example, UDP, TCP, HTTP, Microsoft Print Services, CIFS, or Messaging Application Programming Interface [MAPI]), and other solutions support that protocol generically. In either case, the critical concern is how much the solution can improve the performance of that protocol in the type of environment in which the solution will be deployed. Some of the options that must be considered when dealing with TCP protocol are; Short transaction acceleration. TCP termination. Error correction (Forward Error Correction). Complete recovery from packet loss. SSL Acceleration Use of SSL as an encryption mechanism is a security consideration. The appliance must offer a way of accelerating SSL-encrypted traffic that maintains organizations preferred trust model. The SSL acceleration should be achieved by keeping all private keys within the data center and without requiring fake certificates in branch offices. The appliances must also be able to auto-discover their SSL peers and optimize the SSL traffic, and must also provide centralized management of SSL acceleration capabilities for the entire enterprise via the Management Console. The appliance should provide an integrated Certificate Authority as a part of the solution, that should allow companies the flexibility of using their own security certificates or generating a new certificate for distribution as a part of the licensing process. Other approaches to SSL require fake certificates or server private keys on branch office appliances. These approaches compromise the security of an organizations infrastructure because keys must be distributed across the enterprise, making SSL sessions more vulnerable to attack. Monitoring and Reporting The solution must also be able to offer a set of capabilities for reporting and monitoring with the possibility to generate detailed reports on application usage. It must also support auditing and logging. The reports should be able to generate basic information such as; Current Connections Connection History Connection Forwarding Reports QoS Stats Dropped Reports QoS Stats Sent Reports Top Talkers Reports Traffic Summary Reports Interface Counters TCP Statistics Reports Optimized Throughput Reports Bandwidth Optimization Reports Data Reduction Reports Connection Pooling HTTP Reports NFS Reports SSL Reports PFS Share Logs PFS Data Reports DNS Cache Hits DNS Cache Utilization RSP Statistics Reports Alarm Status Report CPU Utilization Reports SSL Certificates Reports Cost and Pricing Consideration A key factor in choosing a monitoring solution is its cost and return on investment. When considering a WAN Optimization solution; implementation, hardware and software cost must also be brought into perspective. Consideration must also be given to how flexible the solution is. No solution can meet all requirements. How much time, effort and cost will be involved in tuning the solution to meet the needs, can help in determining the total cost of the solution.
Considerations for selecting the right WAN acceleration solution
