Earlier this week my good old BH220 died on me. I had been using it for the last year and it had proven to be quite a cost effective and reliable a model. Its primary uses were as an audio gateway connected to my PC when using skype, and ocasionally for answering mobile calls while I was out (thought that habbit died out pretty soon seeing as the device was too … alien looking).

As for sound quality the BH220 wasn’t too bad. It suffered from the same problems that all headsets suffer from which is a constant low humming. Although annoying at first eventually I was able to just blur out the crackilng in my mind and just be bothered with the conversations i would be participating in. What really used to get to me was the fact that after about fifteen minutes of use my ears used to end up very sore.Seeing as earlier this week the BH220 headset died out on me i decided to take a shot at going for a different style of headset (something less possbily a little more comftable to use in long term). After a little googling about i noticed that the new Jabra headset was recieving quite a few positive comments from the community. Unfortunatly it also seemed to have a history as do most bluetooth headsets to be very inconsistent as to support for the transfering of voice services from a computer to the headset. So soon after i went on ebay and aquired myself a brand new BT500.

The packing of this headset was quite bulky, thankfully the device arrived intact and within a couple of hours was charged and in use. The first thing that I tried out was the Jarba’s ability to pair with more than one device. So I went to my Mac Mini and tried to pair it. The pairining progressed flawlessly and all seemed to be working ok (much to my relief). Next I paired it with my Nokia 6680 and tested it on it. The final test which I performed was the try and swap the ongoing connection from one device to the other. The headset worked like a charm, allowing me to start calls on skype and receiving calls on my mobile phone without the need to re-pair the headset with the desired device every time (though it had to be reconnected from one device to the next but thats quite painless). The quality of the voice connection is nothing exceptional, but I do think it is a little clearer than my old headset.

Overall I am very happy with this device. It has worked as well as advertised and outperformed any of my expectations.

• XHTML - A rigid subset of html which is used to mark-up and style the information.
• DOM - The Document Object Model which can be accessed by the client browsers.
• XMLHttpRequest - The object used to exchange the information asynchronously.
• XML - The format used to transfer the data from the server to the client.

In this tutorial we will see how to create a piece of text that keeps changing using Ajax. Before you start this tutorial make sure that you have a text editor and a web server with PHP extensions available. The following section explains the source files, why they were created, and how to deploy them.

(Tested on: IIS 5 and PHP 5.1.4)

(Development Tools: Textpad and Notepad++)

Implementation

Client Side File (AjaxClientSite.html)

This file contains the html code required to output the information to the clients display. When the page is being outputted the first time, the javascript file is triggered and this sets off the system to start polling the web server for information.

Javascript File (ajaxRotator.js)

This javascript file contains the Ajax code that will perform the calls to the server and will be handling the results returned from the server. When the javascript is triggered, it will start an infinite loop and will request an xml document (using XMLHttpRequest) from the web servers at every iteration. Each time an xml document is returned the javascript posts the html into the current page, thus updating the page without needing a page refresh.

Server File (ajaxServerSide.php)

This file contains the server-side scripts. When the web server is started, this php file will be made available for execution. When the client places an XMLHttpRequest to the server for this file, the php resolves the dynamic page which is to be returned and the information is returned to the client (in this case the text).

A fact that programmers need to bear in mind when using Ajax is that although Ajax does all the processing in the background, an html file is still being transfered at every call. This means that Ajax is useful when communication is performed sparingly (like in a chat or an online server) and should be avoided when there is a need for the system to be very responsive (e.g. online gaming). Ajax is only supported on recent browsers, so developers should be weary when using it to avoid viewers who are not sporting the latest browsers to view the site (e.g. FireFox Mozilla 1.5).

Live Demo:

• Demo

Source Code:

• sample.zip

LINKS:

• Ajax in Wikipedia
• Phpied

Carbide is a Symbian developer tool which was developed as an extension to Eclipse by Nokia. This suite provides developers with a clean interface and support for the C++ or J2ME development APIs. For those who are more used to developing applications in Microsoft Visual Studio, Carbide also comes as a Visual Studio extension to enable development of C++ Symbian applications in Visual Studio.

With this new tool, deploying a development suite has never been easier. All you need to do is follow the simple instructions and you can be up and running within half an hour. Alongside Carbide, you will need to have a copy of the sdk for the targeted platform. The platform sdk can be downloaded from the Nokia website and is available for free to all developers.

Once installed carbide will make all the necessary bindings for you automatically and set itself up to best suit your development needs. When creating a new project in Carbide, a set of template classes with pre-configured build files are provided. This makes development a lot smoother because the developer can be coding as of the first minute after creating the project, without the need for long configuration sessions.

This suite enables debugging in the Nokia emulator which comes with the SDK. One feature which I was surprised not to find in it was the support for on-device debugging. On-device debugging is one of the most commonly used techniques for testing applications. Lack of such a feature might be quite a set-back, especially if the programmer needs to test hardware specific routines (e.g. testing a Bluetooth application)

I believe that this suite is best aimed for companies which have small to medium sized projects, or hobbyist programmers. For larger projects it might be wise to look into Metrowerks CodeWarrior which is better suited for larger projects.

Links:

• Carbide
• Nokia
• Metrowerks CodeWarrior
• Microsoft
• Microsoft Visual Studio
• Microsoft Embedded Studio

Voip on the other hand is a completely new concept. With the advent of this technology, voice calls are no longer vulnerable to the same attacks that the old phone systems were. Voip unlike telephone systems works on the same principles (since it is transported over) as the internet. Now the major flaw of the IP system is that the packets sent over the internet can be intercepted across any of the stops that the packets make. This provides an opening to hackers to try tap into a conversation by attempting to hack into the conversation in pretty much the same way that they would try to have a normal “data pipe” on the internet.

Normal voip calls are transmitted over unencrypted sockets. This can be fixed by using one of the new secure voip clients which encrypt the information to ensure that no one other than the intended person on the receiving end can listen on the conversation. Encrypting the information makes the information hard if not impossible for anyone without the generated key to decipher what is being transmitted.

There are a number of phones that support this kind of encryption. The one I would trust the most would be Zfone which was written by Philip Zimmermann who was also the author of PGP encryption (for those who are new to the encryption marker, its one of the strongest encryption standards on the market). This technology is still just starting to grow so it would be advisable that if you are really paranoid about your privacy, you might want to give Zphone a try.

Links:

• Zfone
• Encryption
  
• Schneier on Security

Although COM programming is now considered to be a dated technology, there are still a lot of COM+ objects in circulation. This makes it impractical to phase out the use of COM+ objects. Thankfully Microsoft catered for such circumstances by adding support for COM+ object references in the .NET Framework. These can be seen in the diagram below:

Apart from support for referencing COM+ objects, Microsoft also added support for the development of .NET objects which can be exposed using a COM+ wrapper. This enables programmers to develop applications with the latest technologies and give languages that can reference COM+ objects the power of using these objects. This can be done by tagging the assembly as a COM+ visible assembly and optionally assigning a strong name to the assembly (some COM+ objects require this feature).

COM+ to date is still essential when developing enterprise applications. Unless the projects are completely .NET related, it is essential that COM+ objects are not shied away from because this might increase a company’s costs in man power and time to redevelop its legacy objects.

Links:

• Microsoft
• Understanding Classic COM Interoperability With .NET Applications

• What is .Net Remoting and how powerful is it?
• What makes it worth all this attention?
• How secure is it in practice

.Net Remoting is a Microsoft product which enables communication across applications. In .Net 1.0 and .Net 1.1, this technology was used to provide applications with a quick and simple means of performing RMI (remote method invocation) calls across applications distributed over a network. This communication is performed over both TCP and HTTP protocols (which support both binary and soap serialization), thus enabling it to be hosted as an independent application or over .Net capable web servers (Such as IIS servers). .Net 2.0 introduces a new channel referred to as the IPC (Inter Process Communication), which allows programmers to publish objects to the current platform (computer) without publishing them over the network (Finally a worthy rival to the System V IPCs on UNIX).

With this technology, programmers have the power of connecting their applications to other applications at runtime through the objects which either of them are publishing. Remoting allows programmers to marshal these objects from one platform (application running on a computer) to another.

Coding of services and providing RMI access to them is no new concept in the realm of programming. What is new though is the fact that not only does remoting allow the programmers to expose a pre-compiled service to a range of applications, but it allows the remoting programmers to migrate functions from their custom assemblies over the internet. This can be useful in a number of scenarios, for example if you need an application to return a set of results once a task has been completed. It is possible to generate an instance of an object and have it marshaled to the server which can then marshal the results back via the object that the client sent to the server.

This unfortunately also means that unless the proper counter measures are taken, there is the chance that a hacker can inject his own code into your server (Code Injection attacks). To avoid this from happening it is imperative that when deploying such applications on an unsecured network (e.g. the Internet), the security is set to allow only strongly typed objects only to be marshaled, to avoid custom objects to be sent across the network. A great deal of information can be found about this topic if one does some further reading about typefilterlevel.

Remoting is a blessing to all .Net programmers, but should be used wisely to avoid leaving loop holes that hackers can exploit. Throughout the last couple of years I have been exposed to a lot of development concerned with remoting and my final thoughts are that it is well worth the trouble of learning to set it up.

Links:

• Microsoft
• Remoting

I’ll have to admit i was surprised to see all those access points showing up. Practically one out of three houses was sporting a wireless router which anyone could discover. Wireless routers are easy to buy and plug in, the question is how many users take the bother on turning on the security features on their wireless access points once they plug them in?

That was a question that my iPAQ could provide an answer for. I loaded up wififofum and had it analyse my surroundings (a freeware network stumbler which i use to test wireless networks when I am setting them up, I also use net stumbler for more rigorous testing routines). Soon enough it returned with a list of all the available access points and what security measures they were sporting. I was pleased to see that quite a few of the users had actually bothered to turn on the security features, but i was also shocked to notice that nearly half of the networks i found were open without any security measures set up to counter anyone living close by or who might be walking, driving or just having a coffee at a restaurant with a pda or laptop equipped with a wireless card.

Securing a network from intruders isn’t too hard now a days. A typical router will sport of the latest encryption software (e.g. WEP encryption is one of the more common forms of encryption, but not the more secure of the lot) which is quite easy to set up. For the more advanced users I would suggest locking the device with mac addresses to ensure that no one is tapping into your network. Securing your network takes minutes, but can spare you hours if not days of problems which might arise from leaving the network open.

Links:

• Vodafone Malta
• Go Mobile
• Wififofum
• Net Stumbler

Over the last couple of months i have had a number of occasions where Voip proved to be very useful. Calling abroad from here (Malta) is expensive to say the least. Voip on the other hand is a standard rate for the entire world, provided that your internet connection is stable enough to support it.

The Voip applications, which worked best for me, were Skype and Voip Buster. Both these clients have similar if not identical price ranges for calling landlines, and free of charge when calling users using computers.

Skype worked fairly well most of the time. I did find Skype’s echo service useful to test whether the connection with the Skype services was clear enough at that point in time to make a call. Skype also offers a variety of clients, which are Windows, Windows Mobile, OSX compatible.

Voip Buster on the other hand offered slightly superior sound quality but is limited to Windows only. Voip works on standard SIP protocol so most probably if one downloaded a SIP client for their preferred platform, they might be able to achieve similar quality of service.

The battle between Voip clients in my opinion is a pointless one. From my own personal experience, no two clients offer the same sound quality on the same connection and price variations are negligible. Which means that every one should keep a copy of their favourite clients handy, and use the one whose network is more feasible at that point in time. Overall I would say that both the mentioned clients give fairly good service quality and very acceptable performance. If the targeted platform is windows I would go with Voip Buster, but if a Pocket Pc is an option the Skype would be the sweeter solution.

Links:

• Skype
• Voip Buster

Links:

• Firefox
• Bug Fixes

Signups are the easiest means of filling your mailbox with unwanted mails. More often than not when downloading free applications like Adobe Reader or Quicktime Media player the user is asked for his or her details, including their e-mail address.  A tick box is usually made available to select if you want to receive news from this website (more often than not ticked for you by default). A common mistake that most users are sucked into is the fact that in their rush to download the desired application, they leave any tick boxes with their default settings which would entitle them to receive the much dreaded “community updates” (a very polite way of referring to spam i.e. unless the user actually did want to sign up for it).

Forum signups are more often than not yet another source of unwanted mail. Forums are spaces where people share and discuss their ideas in an open environment. Modern forums also support the facility (optional in certain cases … restricted in others) to have replies to conversations that the users sent posts to, sent to them by mail. This might be acceptable if the users receive maybe one post a day, but there are cases where if each user partakes in more than one conversation and all of these are forwarded to their respective mailboxes, it might be the case that the user might be receiving an unacceptable number of mails per day.

When signing up for services it is imperative that the user informs himself properly about what the sign up entails because you can never be too cautious when divulging private information such as an e-mail address.