Experimenting with different delivery media for software release

In today's world, software applications can be released in multiple ways. A software application can be released on CD, can be released through a download from a website, can be made such that it is available to be distributed through various partners. All of these are possible configurations, but all of them need some amount of design and effort, and need to be part of the overall strategy for the release of the product.
Let us take each of these and work through different parameters such as ease of preparation, specific needs and customization abilities, and so on, including the cost of doing these.
The 4 main types of software release mechanisms that can be made are (others can be a type of customization of these):
- Release on a media such as CD/DVD. These are a continuation of the earlier strategy of releasing the software on floppy disks and the like. The software application needs to be made in a manner that it fits the DVD mechanism, typically some kind of ISO disk based structure. The software products that I have seen take a typical software installer and create a DVD installer from this structure (would need to even create different mechanisms for Win and Mac if required). CD/DVD are seen as something that are required if you are trying to sell your product through the normal retail mechanisms (through electronic retailers and even through online mechanisms - for example, you could go to Amazon.com and order a copy of the software you want, and the software DVD gets shipped to your address). The customer experience is the simplest in this kind of mechanism, whereby the customer pops in the DVD into the computer, a window pops up asking the user to click on a button (or a number of buttons), and the software gets installed onto the computer of the user.
A problem with this mechanism is that even after the software installer has been tested, there needs to be more testing of the DVD installer, which means that there is an additional level where problems can happen.
- Release through download. Preparing a DVD for the customer to buy has a certain cost. There is a cost to the media, there is a cost of the retail mechanism whereby the DVD needs to reach the customer, and software makers have come up with a mechanism whereby customers are invited to download a copy of the software from the website of the software maker or from other sites. Consider whereby Amazon.com has an option where the customer can opt to download the software from the site rather than asking for the DVD to be shipped to the address of the customer. This ensures that the customer does not have to wait for the DVD to reach their address, and then the problem of saving the DVD in a safe location for re-installation does not come into the picture since the installer is already in the computer of the customer.
Even in this case, the base application installer does need an additional mechanism to provide an interface for the software download process. This is even more important when the software is huge, greater than 500 MB, since you would need to provide a mechanism for the customer to be able to resume the download if it fails during the download process. On the other hand, if you are making a software that is small and is available on websites that provide a large number of software, there may be the need to make some customization in the software installer to be compatible with such mechanisms.
- An option for both the first and second mechanism is to provide a check whereby the software will only work after there is some online verification of the software. These are part of the steps to prevent piracy of the application, and depend on the software application reaching out from time to time to a online verification mechanism on the website of the software maker. Such a mechanism ensures that the software maker can keep on verifying that the software has not been installed on more computers than required. In fact, if you read the recent announcement from a large maker of software, Adobe Systems, it will stop providing users with a physical software mechanism and only use a combination of online delivery with online verification.
- Another distribution mechanism is to provide the software with other software. For example, anti-virus software and other software such as Adobe Reader are available on most new computers and even available with other software that you install. In such cases, the installer that the software makers provide has to have a mechanism for customization. A simple example is where an anti-virus software is distributed along with all Dell machines. These are trial versions of the anti-virus software, and when you decide to purchase, Dell gets a cut of the cost of the software that the customer has paid. For ensuring that this sort of mechanism is in place, the software installer needs additional options, and this means additional effort during the development of the software as well as the testing of the same. However, since such distribution can be a good proportion of overall sales, it is necessary to do the same.
- Another recent mechanism of distribution is the App Store. The app stores for Android and iPad / iPhone are most famous, but there are others as well. Even software for the Mac can be sold through the Mac App Store, and to be available on this distribution mechanism, there could be the need of making significant changes in the software installer. In our case, because of the restrictions that were in place, it was an altogether new project which leveraged what we were doing but needed significant new effort. However, the additional revenue was worth it. 

What are the risks and liabilities with instant messaging?

There are a number of risks and liabilities associated with Instant Messaging. Till today several attempts have been done in order to create a unified IM standard. 

Few have been mentioned below:

1. Session initiation protocol or SIP of IETF.
2. SIP for instant messaging and presence leveraging extensions or SIMPLE.
3. APEX or application exchange.
4. IMPP or instant messaging and presence protocol.
5. XMPP or open XML – based extensible messaging and presence protocol.
6. Instant messaging and presence service of open mobile alliance (this one was developed exclusively for the mobiles.)

Although a number of benefits are given by instant message, there are also many risks and liabilities associated with it. This happens particularly when one uses IM at his/ her workplace. 

Associated risks and liabilities are:

1. Security risks
2. Inappropriate use
3. Compliance risks
4. Trade secret leakage

About Security Risks

- Security risks involve infecting the systems with viruses, worms, spyware and Trojans etc.

- Hackers and crackers make use of IM vectors for making phishing attempts, introducing the file attachments laden with virus and poisoned URLs. 

- Two main methods are used by the hackers for delivering the malicious code via instant messaging:

1. Delivering viruses, spyware or Trojan horses through an infected file.
2. Using the socially engineered text that has a web address enticing the recipient to go to an URL that in turn connects him/ her to a malicious website.

- The first kind of means i.e., the Trojans, worms and viruses propagate themselves by infecting the whole contact list of the user. 

- An attack done through means of a poisoned URL may infect 1000s of user’s system in a very short duration i.e., just when each of the person in the user’s contact list receives a message that appears to be from a trusted source. 

- Thus, when the recipients click on the web address, the whole cycle repeats. - Such infections might be for some criminal or a nuisance reasons. 

- These attacks are getting more sophisticated with time. 

- The connections in the instant messaging are usually in plain text. 

- This is what that makes them vulnerable to threats such as eavesdropping. 

- Also, with instant messaging, the UDP ports are left exposed to the world inviting many potential security vulnerabilities and raising many security issues.

About Inappropriate Use

 

- All the organizations, be of any type need protection against the liability of the inappropriate use of the IM service by the employees. 

- The nature of the IM, be it immediate, informal or anonymous marks it as an abuse of the workplace. 

- In a number of nations, a legal responsibility has been set up by the corporations in order to make sure that the working environment is free of any harassment for the employees. 

- Instant messaging is now included as an integral part of the policies of the companies regarding the appropriate use of services such as e – mail and world wide web and some other corporate assets.

About Compliance Risks

- Using the IM services at workplace also induces a risk concerning the non – compliance to laws and regulations that govern the use of electric communications. 

- The need for the production of the archived business communications that would satisfy the judicial requests is what to which most of the common regulations is related to. 

- There are a number of IM communications falling under the category of business communications and are retrievable. 

What are benefits of instant messaging?

Instant messaging comes with both risks and benefits. Here we focus up on its benefits.

Benefits of Instant Messaging

1. IM serves to be of great advantage in the environments that are geographically dispersed. The major benefit here is that it cut downs on the cost of expensive phone calls.
2. The communication channels can be augmented with the help of instant messaging. This will become clear from the following: suppose there is a conversation going between an external client and the team members can converse within themselves using IM for clarification of some points or plotting a strategy. Here, the IM is said to serve as a back channel.
3. IM serves as an efficient tool for clearing up the clutter on desktop and lets you respond immediately. Most of the business processes are time sensitive: problem resolution, crisis management, customer service etc. to name a few. IM is the solution for all these processes.
4. IM serves well in case of an emergency. The critical information can be rapidly disseminated to the whole company or individuals in cases such as that of health issues. Natural catastrophes, schedule changes, or network outages etc. most of the times, the network of IM services works well when most of other e – mail and phone networks are down.
5. A number of work groups can be linked through IM. Thus, it acts as a bonding between the two groups. The productivity of the ad-hoc contacts can be increased by enabling them to be quickly added to some work group.
6. IM services can also be used for routing the IMs to cell phones through the IM – to – SMS (short messaging service) gateway services. An example of such a service is find – me service.
7. Through IM services people have a quick reach to the experts if they want to survey multiple consultants or to have an instant consultation.
8. IM is a sort of self–service. People can place queries to the human resource virtual agents via person to machine IM services for obtaining information regarding enrollments or benefits. This also provides the staff with access to the data and speeds up the business processes.

More about Intant Messaging

- IM is one of the few small things that are a must for the effective communication 

- However, IM is embraced as a useful utility at workplace by some owners of small businesses. 

- IM services have been used to completely replace the traditional methods of communications or to provide support them. 

- IM is also a real – time means for communication. 

- But the text records of the IM conversations are kept by the exchange just as in the case of e–mail messages.

- This lets the IM function as a quick conference call without having the employees leave their desks. 

- It acts as a powerful means for bringing all the people on a web page common to all.  

- IM is an effective tool for conducting group chat. 

- Nowadays, such IM platforms that allow for group text chatting. 

- Plus, they also allow you to save the chat history. 

- Team members that are at some off- site locations can be connected through IM. 

- Through IM it becomes easy to stay connected and archive files.

How Instant Messaging Works?

Instant Messaging or IM is a very popular trend among all these days. A number of instant messaging services today offer features such as web conferencing, voice over IP and other video calling features. With such features both the IM features and video calling abilities can be integrated. 

About Working of Instant Messaging

- Each IM service has its own client that may be either a browser based client or some separate piece of software.

- These clients typically work with their sole company but some are designed in such a way that they support other services also. 

- There are some other third party clients that can connect with a number of major IM services. 

- Few such examples are Miranda IM, Trillian, Adium and so on.

- The IM program installed on your system connects to the IM Company via internet. 

- Here the user’s identity is verified. This process is termed as authentication. 

- After verification, the information or the ‘messages’ can be start exchanging between the users. 

- This IM program installed on your system is called the IM client. 

- When you start it up, it connects to the IM server of its company. 

- To log in to the IM service, you need to have an user ID and password. 

- Once they are verified to be correct, you are logged in. You are connected to the IM network. 

- A list of your friends who are currently online will be displayed. Your list will be changing as per who all are signing in and out. 

- People might have set different IM status such as ‘online’, ‘offline’ or ‘busy’ etc. when you type a message to your friend and hit enter; this message reaches him after traveling from your IM client through the IM server to which it is connected.

- The messages you send reach directly to your friends. 

- A pop up IM window displays your message to them. 

- As the chat progresses further, the messages travel to and fro between the two clients with very less delay of time. 

- Consider sending a file to your friend. You attach the file to the text and press enter. 

- Then your IM client will place an inquiry at the IM server to know the status of your friend. 

- If your friend is connected to internet, a direct connection to his IM client is established.

- The reason for using a direct connection is that it is much faster and efficient rather than sending files through a number of intermediate servers in case of an indirect connection. 

- Also, using a direct connection saves on bandwidth. 

- Instant messages are quite small in size and messages of a whole month may sum up to only 1 megabyte that is quite a tiny amount of space.

- This also enables instant messaging services to work equally on slow as well as fast internet connections.

How Inter-operability is supported by Instant Messaging?

- An instant messaging service can support a number of simultaneous conversations. 

- These are small applications that can cater to only small business needs. 

- But for larger organizations more sophisticated applications are required that can work in cooperation. 

- The enterprise versions of these applications provide solution to these problems.

- Some examples of larger IM applications are:

1. XMPP
2. Lotus same time
3. Microsoft office communicator and so on.

- These applications can be integrated with the workflow systems.

- These applications are also known as EAI or enterprise application integration as per certain constraints such as data storage in a specified format. 

- Several attempts have been made for creating a unified standard. 

What is meant by Instant Messaging?

Almost everyone today is familiar with the term ‘Instant messaging’ or IM in short. 

- This is a type of communication that sustains over the internet and quickly transmits the text based messages between people (i.e., senders and receivers). 

- The basic purpose of IM is to provide “real time direct written language–based online chat”. 

- It does this through push mode and other shared clients between two or more people using personal communication devices (mobiles) and personal computers. 

- A network such as the internet is used for conveying the text message for the person it is intended for. 

- IM addresses two kinds of communications namely:

1. Point – to – point communications i.e., from one person to another one person.
2. Multicast communications i.e., from one sender to a number of receivers.

- Nowadays, much enhanced modes of communication have been introduced by advanced instant messaging services. 

- Some enhancements are inclusion of video chat, audio calling and hyperlinks to other media etc. 

- The umbrella term is the online chat under which the concept of IM falls. 

- The similarity between them is that they are text based, happens in real time and offer bi – directional flow of messages. 

- The only distinction is that the IM is based up on clients. 

- The connections between the known users are facilitated by these clients only through a contact list (also known as friend list or buddy list).

- On the other hand, chat works up on web – based applications that facilitate communication between multiple users.

- A number of communication technologies that facilitates text based communication are combined together to provide the service of instant messaging. 

- The biggest feature of the IM – chats is that they take place in real time just like a phone call. 

- IM is different from the other web services such e–mail in the sense that users here perceive the “quasi – synchronicity of the communications”. 

- In IM, you can message only those people who are online at that time. 

- However, there exist some systems that allow you to message offline people, thus drawing some similarity between e–mail and IM.

- IM is cheap and effective means for efficient communication. 

- It allows immediate receipt of the message and also enables us to reply back immediately. 

- However, it is not necessary that the transaction control might support the IM. 

- In some cases there are additional features that make IM more interesting as mentioned below:

1. Enabling users to see each other via web cam.
2. Using headphones and microphones and talk for free over internet.
3. File transfers
4. Saving a text conversation for future reference.

- Instant messaging came much before the internet and first appeared on systems such as multics (multiplexed information and computing service) and CTSS or compatible time sharing system which are multi – user systems. 

- Some of the IM services such as ytalk, talk, ntalk and so on, peer – to – peer protocol.

- Some other examples of early IM services are:

1. Zephyr notification service
2. Bulletin board system or BBS
3. Freelancin round table
4. Compuserve CB simulator: this was the first dedicated online chat service

- Real time text was also a feature of these early instant messaging services.   

- AOL’s real time IM implements the modern real time text feature as an optional feature. 

- Video calling features such as web conferencing services can integrate both IM abilities and video calling.

What is Dynamic synchronous transfer mode (DTM)?

Dynamic synchronous transfer mode or the DTM is a technology developed for optical networking. The ETSI (i.e., the European telecommunications standards institute) standardized this technology in the year of 2001 marked with the following beginning specification ‘ETSI ES 201 803 – 1’. 

This is a circuit switching network technology that doubles as a time division multiplexing technology too. Actually, this technology is built up on a combination of the switching and transport.

This technology guarantees to provide QoS or quality of service for services that are involved with the streaming of videos. 

However, it might be used for packet – based services also. It is marketed for the following:

1. Professional media networks
2. Mobile TV networks
3. DTT or digital terrestrial television networks
4. Content delivery networks
5. Consumer oriented networks (for example, triple play)

What is Switching?

- Switching of the channels is specified by DTM. 

- This is what that makes it different from the other transmission techniques that we have, for example, SONET (synchronous optical networking), SDH (synchronous digital hierarchy) and so on. 

- End to end provisioning is done for the DTM channel over a network with general topology through the use of control signaling.

- DTM therefore represents a circuit switched system. 

- The switches are nothing but time space switches that guarantee the QoS property. 

- The allocation of the resources is done physically for each channel in the switch. 

- This is quite contrary to the switches that are based up on packets or cells. 

- In those kind of switches there is always a competition for resources between the packets and cells. 

- Such a competition leads to delaying and discarding of the packets and cells. - Other methods offer a shared resource allocation mechanism that draws a limit for the packet and cell switches regarding their utilization of the network in such way that the QoS is maintained at a certain level. 

- But DTM does not follow this shared allocation mechanism rather it implies that a network can be loaded up to full limit theoretically and still can guarantee the QoS. 

- Thus, here real utilization is more like a question of adaptation of the network topology as well as its link capacities considering the actual traffic matrix.

- Packet and cell based switching technologies are more suited to statistical multiplexing.

- It means whenever a packet streams in a router come at an outgoing link that is common to all of them, buffering is carried out until the resources are free on that particular link.

- In this way, it becomes possible to make use of the outgoing link to the maximum degree possible without causing many delays. 

- This also proves fitting for the best effort traffic. 

- But there are certain QoS requirements of the streaming media that cannot be ignored. 

- Streaming traffic is by nature not statistical and therefore is better maintained by end to end resource allocation.

- This category is applicable for audio and video services.

- This is not exclusive of the IP traffic gained via guaranteed QoS transport if majority of the content is audio and video. 

- Some other technologies such as that of IP and Ethernet were also adopted for the same purpose. 

- Multi protocol label switching or MPLS can be applied to the carriage network for improving the reliability as well as determinism that is required by most of the streaming media. 

- This technology is applied along with the techniques such as the forward error correction.

- Ethernet has been made supportive for audio and video transmission by improvement in technologies such as the provider backbone bridge traffic engineering. 

- The development of dynamic synchronous transfer mode took place at the royal institute of technology. 

What is meant by Holographic Data Storage?

Currently the conventional magnetic and optical data storage dominates the field of high – capacity data storage. But another technology called the holographic data storage holds the potential to lead this area. Now what is this technology? We shall discuss about it in this article. 

Difference between Conventional storage methods and Holographic Data Storage

- The conventional methods such as the optical storage and magnetic storage technologies depend up on the recording of the individual data bits on the distinct optical and magnetic on the medium’s surface. 

- In the holographic technology, the information is recorded throughout the medium’s volume.

- Multiple images can be recorded in the same medium area via utilization of the light at varying angles. 

- Further, in the conventional storage methods the recording takes place in a linear fashion whereas, 

- In holographic storage, millions of bits can be recorded and read in parallel thus increasing the rates of the data transfer more than what are offered by the conventional methods.

Features of Holographic Data Storage

Data Recording: 

- The information is stored in a thick photosensitive optical substance with the help of an optical interference pattern. 

- A laser beam is divided into two un-identical optical patterns (formed of light and dark pixels) and is projected towards the medium. 

- A multitude of holograms in one volume is recorded by making adjustments in the wavelength, reference beam angle, media position etc.

Data Reading: 

- For reading the stored data, the same reference beam is reproduced for the creation of the hologram. 

- This light beam is focused up on the photosensitive material that illuminates the interference pattern which leads to the diffraction of the light. 

- The pattern is then projected to the detector. 

- The data is then read in parallel at a rate more than that of millions. 

- This means high data transfer rate. 

- It takes less than 0.2 seconds for accessing the information from a holographic drive. 

- Holographic data storage has offered a solution to many companies for preserving and archiving the information. 

- The WORM (write – once, read many) approach provides assurance about the content security, risk of modification and overwriting of the information. 

- This technology provides hope for storage of data without degradation for 50 plus years which is quite more than the current options.

- However, if the same trend is followed, and it becomes possible to store data for 50 – 100 years in same format, that would still be irrelevant. 

- This is so because the format will be changing in less than 10 years.  

Types of Holographic Media

- Holographic media is of two types namely:

1.  The re-writable media and
2. The write once medium.

- In the former type, the changes can be reversed but in the latter can the changes are irreversible.

There is no point in the competition between the holographic storage and the hard drives since the former can find a market that is based up on the virtues like access speed. 

- The holographic data storage technology does seems to have a future in the video game market. 

In the year of 2009, the GE Global Research did came up with their own demonstration of the holographic storage medium that could stand the discs that had read mechanisms somewhat similar to that of the blu–ray disc players. 

Estimation Techniques - For Web Engineering Projects

Early estimation is required during planning even though there is a huge chance that these are proven wrong. Some uncertainty is unacceptable and some solid techniques and concrete procedures help reduce the inaccuracy of estimates.

Estimating techniques for web engineering projects adapt the agile process model. Along with the agile estimation approach, a modified function point (FP) measure can be used to develop an estimate for a web application. Roetzheim suggests for web application estimation, the information domain values while adapting function points are:

- Inputs include maintenance screen, input screen or form or each tab using a tab notebook.
- Outputs include static web page, dynamic web page script, each report whether web based or administrative in nature.
- Tables include logical tables in database, each XML object if XML is used to store data.
- Interfaces are logical files into our out of the system boundaries.
- Queries are a message oriented interface and they are externally published.

According to Mendes:
The best way to determine the volume of the web application is by :
- predictor variables that are associated with application like page count, function count, media count,
- web page characteristics like page complexity, linking and graphic complexity,
- media characteristics like media duration,
- functional characteristics like code length.

Empirical estimation models for:
- total project effort
- page authoring effort
- media authoring effort
- scripting effort
can be evaluated by using these measures.