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Opnet - finger pointing raised to high art

Opnet - finger pointing raised to high artDon't believe it will workOne of the biggest drawbacks to virtualizing everything is that you virtualize your problems! Multiple layers of virtualization along with complex architectures makes tracking down performance problems just about impossible. Here's one of my own examples: EMC disk arrays...

Tags: Storage management, Storage, OPNET

Discussion threads 2009-05-21

Additional Resources

Layer 7 Application Services Governance

Layer 7 Technologies', CEO, Paul Rochester, and VP of Engineering/Chief Architect, K. Scott Morrison, stopped by telephonically to introduce their company, its philosophy and bring me up to date on their product portfolio. The company offers server appliances and virtual appliances that take on the tasks of firewall, compliance enforcer,...

Tags: Web, Layer 7 Technologies Inc., Service-Oriented Architecture (SOA), Channel Management, Web Services, Security, Enterprise Software, Software, Marketing, Dan Kusnetzky

Blog posts 2009-07-23

News to know: Botnets; Adobe patch day; NetApp; Craigslist

Here are today’s notable headlines. You can get News To Know via email alert and RSS daily.  For continuous updates see BNET’s around-the-Web tech coverage. Dancho Danchev: Inside the botnets that never make the news - a gallery Images: Inside the botnets that never make the news right ...

Tags: Adobe Systems Inc., NetApp Inc., Craigslist, Dana Blankenhorn, Microsoft Corp., Robots, GPS, Document Management, Storage, Emerging Technologies, Consumer Electronics, Personal Technology, Enterprise Software, Software, Finance, Managerial Accounting, Hardware, Larry Dignan

Blog posts 2009-05-21

Opnet - finger pointing raised to high art

Although I'm sure that they are going to cringe when I say this, Opnet clearly has raised the art of finger pointing to a high art. That is, their products are designed to live in a highly disbursed, perhaps virtualized computing environment and quickly put the finger on application performance...

Tags: Art, Channel Management, Marketing, Dan Kusnetzky

Blog posts 2009-05-20

NYK Business Systems Americas - Extrahop customer profile

I recently had the opportunity to communicate with the Application Support Manager at NYK Business Systems Americas, Inc. to learn more about what the company was doing and why they chose to deploy products from Extrahop Networks (see the post, ExtraHop for more information about Extrahop). Please introduce your...

Tags: Real Estate, Data Centers, Business Operations, Storage, Hardware, Data Management, Dan Kusnetzky

Blog posts 2009-05-04

Impact of Implementing VPN to Secure Wireless LAN

Many corporations are seriously concerned about security of networks and therefore, their network supervisors are still reluctant to install WLANs. In this regards, the IEEE802.11i standard was developed to address the security problems, even though the mistrust of the wireless LAN technology is still existing. The thought was that the...

Tags: VPN, WLAN, Wireless, LANs, Wireless LANs, Wi-Fi, Networking, Wireless And Mobility, Network Technology, Security

White papers 2009-01-01

A MAC Protocol Based on Adaptive Beamforming for Ad Hoc Networks

This paper presents a novel slotted MAC Medium Access Control protocol for nodes equipped with adaptive antenna array in ad hoc network. The protocol relies on the ability of antenna to uses DOA (Direction-Of-Arrival) information to beamform by placing nulls in the direction of interferers thus maximize SINR (Signal to...

Tags: Advertisement, MAC, Protocol

White papers 2009-01-01

Switched Optical Star-Topology Network With Edge Electronic Buffering and Centralized Control

A star-topology local area network is designed to carry optical packet traffic, employing collision-free switching. Data forwarding is under centralized control based on scheduled resource reservation, eliminating the need for optical buffers in the central switch. Packets are stored in electronic buffers within the end stations prior to their electronic-to-optical...

Tags: Network, Buffer, University Of Essex, Star-topology Local Area Network, Networking

White papers 2008-05-13

Impact of QoS on Application Response Time

Quality of Service QoS recourses to the capability of a network to provide better service to selected network traffic over various technologies. This paper compares three different algorithms for packet queuing using the simulator program OpNet (OpNet is a network simulator, including a library of detailed protocol and application models...

Tags: Database, QoS, Network, Research India Publications, Tcp/Ip, Networking

White papers 2008-04-01

NCTUns Simulation Tool for WiMAX Modeling

This paper describes the NCTUns simulation tool that facilitates the WiMAX studies of network behaviors and performance analysis. It compares NCTUns with ns-2, QualNet, and OPNET Modeler. The design paradigms of these tools are elaborated. Then it enumerates the WiMAX-related functions that can be simulated by these tools. The performance...

Tags: Network, Tool, Modeling, WiMAX, Productivity, Wi-Fi, Wireless And Mobility, Networking

White papers 2007-10-24

OPNET Model of TCP With Adaptive Delay and Loss Response for Broadband GEO Satellite Networks

Transmission Control Protocol TCP provides reliable transport services for Internet applications. Broadband Geostationary Earth Orbit GEO satellite networks play an important role in providing Internet access and network connectivity. They are characterized by long propagation delays and high bit error rates, which negatively affect TCP performance. The paper proposed a...

Tags: Broadband, TCP, Tcp/Ip, Networking

White papers 2007-08-12

Evaluation of a Novel Low Complexity Smart Antenna for Wireless LAN Systems

A novel smart antenna is described, which is conceived as a low complexity inexpensive upgrade for IEEE 802.11b/g Wireless Local Area Network WLAN systems. Using smart antennas to increase network throughput by improved spatial reuse is not normally possible for systems using the 802.11 Medium Access Control MAC, unless centralised...

Tags: WLAN, IEEE, Antenna, LANs, Wireless LANs, Wi-Fi, Wireless, Networking

White papers 2006-11-20

Performance Evaluation of Wireless IEEE 802.11b Used for E-Learning Classroom Network

This paper presents an evaluation study of an IEEE 802.11b Wireless LAN WLAN applied in E-learning classroom. The simulation is conducted using OPNET IT Guru 9.1. Also, this paper presents a simulation study to estimate the appropriate number of E-learning clients that can be supported in the WLAN as well...

Tags: Performance, Network, Performance Evaluation, Wireless, E-learning, Training And Certification, Wireless LANs, Wi-Fi, Wireless And Mobility, Enterprise Software, Software

White papers 2006-11-07

Improving TCP Performance Over 802.11 WLAN With Radio Network Feedback

A new technique is proposed that enables TCP to distinguish wireless packet losses from congestion related packet losses. This is achieved by introducing a wireless enhancement proxy WENP at layer 3 in the base station that monitors the TCP packet flows in both directions, detects wireless packet drops and provides...

Tags: 802.11 Wireless LAN, IEEE 802.11, Network, Radio, TCP, University Of Canterbury, TCP Reno Congestion Control Mechanism, Tcp/Ip, Networking, Wireless

White papers 2006-08-18

TCP End-to-End Performance Improvement Over Wireless Networks Via Early Packet Loss Recovery

A new technique is proposed that enables TCP to early detect packet losses, which cannot be detected and retransmitted using the standard fast retransmit mechanism, and to quickly retransmit those packets without waiting for a timeout to occur, thereby improving TCP performance. Early Packet Loss Recovery EPLR is achieved by...

Tags: Recovery, Performance, Network, TCP, Wireless Network, Wireless, University Of Canterbury, Early Packet Loss Recovery, Tcp/Ip, Networking

White papers 2006-08-11

Performance Comparison of IP, MPLS and ATM Based Network Cores Using OPNET

The core components of a network play vital role in its enhancement. For launching and providing Internet applications and services, vendors have come up with a variety of different technology based network cores and other components of Internet backbone. Among all the challenges for an efficient network core, traffic-routing is...

Tags: Performance, MPLS, Network, IP, Internet, Networking, ATM, Network Technology

White papers 2006-08-05

Nonlinear Complex Behaviour of TCP in UMTS Networks and Performance Analysis

This paper presents a study of nonlinear complex behaviour in UMTS networks. Using the fundamentals of chaos theory the paper explores the chaotic nature of the TCP protocol when used in 3G UMTS mobile networks. Furthermore the paper evaluates the impact of nonlinear dynamic behaviour on the UMTS network performance....

Tags: UMTS, Performance, Network, TCP, University Of Newcastle, Cellular Phones, Tcp/Ip, Networking, Consumer Electronics, Personal Technology

White papers 2006-05-12

An Efficient Algorithm for Inquiry Process in Bluetooth

The basic Bluetooth network topology piconet consists of a master and one or more slaves. The network formation is based on inquiry and page processes. This paper presents a device discovery algorithm whose objective is to minimize the duration of the inquiry period. The algorithm is tailored for the scenario...

Tags: Algorithm, Network, Network Formation, Bluetooth, Engineering, Wi-Fi, Wireless And Mobility

White papers 2004-08-24

Simulation Evaluation of Wireless Web Performance in an IEEE 802.11b Classroom Area Network

This paper presents a simulation study of an IEEE 802.11b Wireless LAN WLAN used as a classroom area network. The simulation is conducted using OPNET Modeler 9.1. The first part of the paper discusses parameterization and validation of the simulation model, based on empirical measurements in a wireless classroom environment....

Tags: IEEE 802.11, Network, University Of Calgary, WLAN, Wireless Web, Wireless LANs, Wi-Fi, Wireless, LANs, Networking

White papers