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- Database Access via C# ADO.NET
- C# Reflection
- Object Relational Mapping and Java Persistence: Data Modeling and Legacy Schemas
- C# GUI Programming
- C# Assembly Programming
- Using the C# system.io Namespace
- Using C# Generics
- An Introduction to Concurrent Java Programming
- Using C# Interfaces
- Getting Your Software onto Linux
- What’s Wrong with Modern Software Development?
- Building a Solid Foundation for JPA and Hibernate
- Java Patterns for MPLS Network Management, Part 2
- Java Patterns for MPLS Network Management, Part 1
- Getting Started with Spring Web Flow
- Application Contexts for Spring Web Services
- Spring Web Services with SOAPUI
- Hit the Ground Running with the Spring Framework
- Building Multithreaded C# Applications
- Hosting an LDAP Server in VMWare
- Integrating Linux Into Your Windows Environment
- Understanding C# Object Serialization and Object Graphs
- Further Subversion Steps: Get Motoring with TortoiseSVN
- Further Steps with the Java Sound API
- 5 Easy Steps to Using Virtualization Technology
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- Targeted Client Upgrades: Creating a Flexible, Low-cost Application Upgrade Mechanism
- Java DMK and Legacy IT Management
- Aspect-Oriented Programming: A Tool for Internationalization
- Achieving Separation of Concerns Using BPEL
- Mobile Java with J2ME
- Graph Algorithms in Java
- Design Patterns in Java: The Observer
- Five Steps to Managing Unstructured Data with Derby
- Using the Java Sound API
- Moving C++ and Java Programmers Up the Value Chain
- Java Nuts and Bolts: Copy Constructors, Cloning, and Linked Structures
- Further Steps with Derby: Derby Embedded in a Browser
- Further Steps with Derby: Defining and Accessing Your Data
- IT Management Using C# with WMI
- Using Derby as a Network Database Server Engine
- Five Steps to Further Success with Subversion
- Improve Software Installation with AntInstaller
- Multithreaded Java GUI Programming
- The C++ Strategy Pattern for Multiple Network Events
- Java Collections and Iterators
- The C++ State Pattern for Network Operations
- C++ Nuts and Bolts: Casts, Call-by-Reference, and Inheritance
- Getting Started with Subversion on Windows
- Getting Started with Derby
- C# Callback and Event Mechanisms
- Some Rules for Safer Java Programming
- Inheritance and Polymorphism in C++ and C#
- IT Management: Dipping into the Platform with C#
- C# and IT Management Infrastructure
- C++ to C# Migration
- Service Oriented Architecture with Apache Axis
- Speech-Enable Your Java Software
- Generic C++ for Networks
- C++ Inheritance and Polymorphism
- Thinking Recursively with C++
- Aspect-Oriented Programming for Production Code
- C++ Modularity with Namespaces and Exception Handling
- C++ Chain of Responsibility Pattern: Network Events
- The Web Services Distributed Management (WSDM) Standard
- MPLS Network Design Nuts and Bolts
- BPEL: The Next Big Thing in Software?
- On-Demand Computing: A New Paradigm
- Software Plasticity with Aspect-Oriented Programming
- Parser Configuration in JAXP
- Publish and Subscribe Using C++ and the Observer Pattern
- Java Application Servers: Seven Things You Should Know
- Legacy IT Management using C++
- Software Futures: Architecture
- Saving Money with Legacy Data
- Saving Money with Legacy Source Code
- MPLS and Ethernet: Seven Things You Need To Know
- Quality of Service, Part 2 of 2: Managing Enterprise QoS
- Quality of Service, Part 1 of 2: Elements of Enterprise QoS for Voice Over IP
- The Need for Autonomic Computing
- A Blade Server Primer
- Workflow-Based Network Management
- SNMP Versus Command-Line Interface (CLI) for Network Management
- Security and the Management Plane, Part 2
- Security and the Management Plane, Part 1
- Network Management and MPLS
- Managing Large Networks: Problems and Solutions
- Getting my first iPhone app into the App Store
Having just posted my first iPhone to the App store, I wanted to briefly describe the experience and at the same time to debunk some myths I’ve heard about since I started.
- SOA and IT Strategy
It's a rare organization that has a comprehensive IT strategy. Why does a strategy matter? For one thing, IT is now part of the DNA of all organizations. So, an effective strategy is a key business element.
- IT staff and contractors - why they matter
IT salaries and contract rates in free fall
- A day in the life of a software contractor - Forming good relationships
I wanted to share a few findings with you about my recent forays into the world of software contracting.
- The path to programming excellence ? C++ to Java from C, Pascal and others
I’ve probably used more programming languages down the years than is good for me. And like many other programmers, I mostly use Java nowadays. During my most recent product development, I made a foray back into C in order to do some Ethernet protocol analysis. Some languages are just better than others for such tasks - remember C is a system language so you can use it to dig right into the platform. Java is more constrained because of the JVM boundary. In the end, I integrated the down-to-the-metal C code right back into Java using JNI.
- Moving up the value chain
Following on from my previous posting on decision-making quality, I wanted to talk a little about the related subject of the value chain.
- Decision-making Quality
The need for forward momentum is perhaps one of the negative consequences of the fast pace of modern life. This issue is discussed in ex-world chess champion, Garry Kasparov’s latest book “How life imitates chess”. Kasparov feels that decision-making suffers if insufficient time is taken. He’s not alone. Edward de Bono – the inventor of lateral thinking once said that apart from extreme emergencies there is rarely a need to think quickly. Warren Buffett moved his offices out of
From the author of
Network Management, MIBs and MPLS: Principles, Design and Implementation
Elements of VoIP Delay
For VoIP communication to occur as in Figure 1, we typically encounter the following types of delay components:
Coder delay: Analog-to-digital speech conversion and PCM compression
Packetization delay: Time to fill a packet payload
Serialization delay: Time to push a packet payload onto the wire
Output queuing: Scheduling a voice packet out of device queues
WAN delay: Transmission delay across the WAN
Dejitter delay: Smoothing the inter-arrival time of voice packets
Each of these delay components contributes to the overall budget; the design engineer must mix-and-match them appropriately. If the engineer gets it wrong, the network may exhibit variable delay, giving rise to unsatisfied customers such as our friend Terry Dactyll.
Perhaps the most subtle delay component is that of output queuing, which relates to basically getting voice packets through intermediate routing devices. The complication arises because routers are used for data and voice packets; in other words, non-real time and real time.
Let's say that three packets are in transit through a router, as illustrated in Figure 3. The rightmost data packet is already being queued prior to be being pushed onto the line. Even if a voice packet has just arrived behind this data packet, the queuing already in progress will not stop. However, the voice packet on the left side of Figure 3 will skip the data packet ahead of it. This strategy helps to preserve the high priority of voice packets as they move through the network.
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Figure
3 Voice packet queue precedence.
If the router becomes congested, it may start to drop packets. This is not such a disaster for data packets (which can be retransmitted) but it has a serious impact on a voice service. As we've seen, voice service is unforgiving of both delay and packet loss. The same is true of advanced surveillance projects such as planetary exploration (or possibly even in the unmanned drone planes operating over Afghanistan). Clearly, this class of application has a one-way data stream—we're looking at them and not vice versa! Data is acquired and transmitted back to the receiving station; by the time it's received, it can't be retransmitted due to speed of acquisition, limited storage, and so forth. Given the critical nature of these applications, it's commonplace to add extra redundancy to the data prior to transmission, which allows the receiver to correct any errors that occur in transit. This is the interesting area of error correction as opposed to error detection. Correction schemes allow receivers to fix errors, whereas detection schemes usually require retransmission.
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