Showing posts from December 6, 2009

Markov Model

What is a Markov Model?
Markov models are some of the most powerful tools available to engineers and scientists for analyzing complex systems. This analysis yields results for both the time dependent evolution of the system and the steady state of the system.

For example, in Reliability Engineering, the operation of the system may be represented by a state diagram, which represents the states and rates of a dynamic system. This diagram consists of nodes (representing a possible state of the system, which is determined by the states of the individual components & sub-components) connected by arrows (representing the rate at which the system operation transitions from one state to the other state). Transitions may be determined by a variety of possible events, for example the failure or repair of an individual component. A state-to-state transition is characterized by a probability distribution. Under reasonable assumptions, the system operation may be analyzed using a …

Out-of-Band (OOB) Splice

What is the OOB Splice?
An OOB splice is an independent, separate TCP connection made on the first connection between two peer Steelhead appliances used to transfer version, licensing and other OOB data between peer Steelhead appliances. An OOB connection must exist between two peers for connections between these peers to be optimized. If the OOB splice dies all optimized connections on the peer Steelhead appliances will be terminated.
The OOB connection is a single connection existing between two Steelhead appliances regardless of the direction of flow. So if you open one or more connections in one direction, then initiate a connection from the other direction, there will still be only one connection for the OOB splice. This connection is made on the first connection between two peer Steelhead appliances using their in-path IP addresses and port 7800 by default. The OOB splice is rarely of any concern except in full transparency deployments.
Case Study In the example below, the Client is…


RIVERBED ANNOUNCES STEELHEAD MOBILE 3.0 Mobile Solution Complements Broader Steelhead Appliance Deployment and Speeds Enterprise IT Infrastructure Performance; Provides Acceleration for Windows 7 and 64-bit Systems SAN FRANCISCO – November 02, 2009 – Riverbed Technology (NASDAQ: RVBD), the IT infrastructure performance company for networks, applications and storage, today announced upcoming enhancements to its Mobile WAN optimization solution to address the productivity challenges global organizations face when managing remote and mobile workforces. Riverbed® Steelhead® Mobile increases employee productivity while on the road, working from home or connected wirelessly in the office by providing application performance improvements. With this release, Riverbed will provide acceleration for Windows 7 and 64-bit systems for mobile end users. In addition, organizations will be able to take advantage of improved flexibility and simplified manage ment functionality to provide mobile worker…

Riverbed Cascade Gateways vs Cascade Profiler vs Cascade Sensor

Cascade Gateways collects network flow data already existing in an organization’s network provides intelligent de-duplication retaining information on where each flow was recorded, and sends this condensed data to the Cascade Profiler. Cascade Profiler complements this information with layer 7 application and response time data retrieved from a Cascade Sensordeployed in the datacenter. These records are then further enhanced with user identification information provided by active directories, switch port information, QoS, and SNMP data. The result is a complete view of a business application flow from the back end server to the users desktop. Cascade also provides an extensive set of integrations, with management systems typically deployed in an IT environment to further streamline workflows and provide value across multiple operations teams.