<?xml version='1.0' encoding='UTF-8'?><?xml-stylesheet href="http://www.blogger.com/styles/atom.css" type="text/css"?><feed xmlns='http://www.w3.org/2005/Atom' xmlns:openSearch='http://a9.com/-/spec/opensearchrss/1.0/' xmlns:georss='http://www.georss.org/georss'><id>tag:blogger.com,1999:blog-7292128642496133099</id><updated>2009-11-06T19:48:29.687+05:30</updated><title type='text'>A Programmer's Thought</title><subtitle type='html'>The blog contains some software tricks and solutions which I found during my professional career. It also contains my thoughts on different technologies in computer&amp;#39;s world.</subtitle><link rel='http://schemas.google.com/g/2005#feed' type='application/atom+xml' href='http://somkar.blogspot.com/feeds/posts/default'/><link rel='self' type='application/atom+xml' href='http://www.blogger.com/feeds/7292128642496133099/posts/default'/><link rel='alternate' type='text/html' href='http://somkar.blogspot.com/'/><link rel='hub' href='http://pubsubhubbub.appspot.com/'/><author><name>Omkar Singh</name><uri>http://www.blogger.com/profile/02226583489163295452</uri><email>omkar.pune@gmail.com</email></author><generator version='7.00' uri='http://www.blogger.com'>Blogger</generator><openSearch:totalResults>6</openSearch:totalResults><openSearch:startIndex>1</openSearch:startIndex><openSearch:itemsPerPage>25</openSearch:itemsPerPage><entry><id>tag:blogger.com,1999:blog-7292128642496133099.post-1184680190096427017</id><published>2009-05-09T07:29:00.002+05:30</published><updated>2009-05-09T07:50:13.731+05:30</updated><category scheme='http://www.blogger.com/atom/ns#' term='orkut'/><category scheme='http://www.blogger.com/atom/ns#' term='nielsen'/><category scheme='http://www.blogger.com/atom/ns#' term='facebook'/><category scheme='http://www.blogger.com/atom/ns#' term='messaging'/><title type='text'>Why Social Networking Sites gaining Popularity?</title><content type='html'>&lt;p class="MsoNormal"&gt;The popularity of social networking sites and blogs is gaining very rapidly. This is very evident from &lt;span class="apple-style-span"&gt;&lt;span style="line-height:115%;Verdana&amp;quot;,&amp;quot;sans-serif&amp;quot;; font-family:&amp;quot;;font-size:9.0pt;color:black;"&gt;&lt;a href="http://www.nielsen-online.com/pr/pr_090309.pdf"&gt;Nielsen Online research&lt;/a&gt;&lt;/span&gt;&lt;/span&gt; which says social networking sites along with blogs are forth most popular internet activity. Now two out of third internet users, uses social networking sites. The research tells that the social networking site surpasses the email in popularity. Once of the major reason is social networking sites are replacing the email. Now people prefer to use these networking sites to send short messages.&lt;/p&gt;  &lt;p class="MsoNormal"&gt;It is not only the number of users but also the time spent by an individual, on these social networking sites, is increasing. I always wonder why people are not get bored by these networking sites. Some of the reasons which I can think are: &lt;/p&gt;  &lt;p class="MsoNormal"&gt;&lt;b style="mso-bidi-font-weight:normal"&gt;Easy to use:&lt;/b&gt; This main reason for the popularity of social networking site is their easiness of use. Even a novice internet user can easily access most part of the social networking sites. On these sites finding a friend is very easy. Most of the sites like ‘Facebook’ searches the friends and prompt the uses to add them. &lt;span style="mso-spacerun:yes"&gt; &lt;/span&gt;&lt;/p&gt;  &lt;p class="MsoNormal"&gt;&lt;b style="mso-bidi-font-weight:normal"&gt;Free to use:&lt;/b&gt; Most of the social networking sites are free to use. &lt;span style="mso-spacerun:yes"&gt; &lt;/span&gt;The user just needs to register. The information entered while registering is used to build the profile of the user. Based on the profile these sites help to find friend already existing on the network. I found many of my old childhood friends, with whom I lost contact, thanks to these networking sites.&lt;/p&gt;  &lt;p class="MsoNormal"&gt;&lt;b style="mso-bidi-font-weight:normal"&gt;Easy to find people of similar interest:&lt;/b&gt; Social networkings sites are not just about old friends but it help to find new friend of same interest. These sites facilities to make group based on location /interest/language/religion, thus making it easy for users to find people of similar interest.&lt;/p&gt;  &lt;p class="MsoNormal"&gt;&lt;b style="mso-bidi-font-weight:normal"&gt;Different focus: &lt;/b&gt;Currently there is a variety of networking sites are available. Although most of popular sites focus there are some which focuses on a particular topic. For the example Linked-in focused on building professional network, while some networking sites focus on music video file sharing&lt;/p&gt;  &lt;p class="MsoNormal"&gt;&lt;b style="mso-bidi-font-weight:normal"&gt;Many applications to hang with&lt;/b&gt;: These sites provide many online games and applications for dating, photo sharing etc. These applications not only hang users on these sites but also attract frequent visit. . A comparison between products of famous networking sites can be found &lt;a href="http://social-networking-websites-review.toptenreviews.com/"&gt;here&lt;/a&gt;.&lt;/p&gt;  &lt;p class="MsoNormal"&gt;Though the popularity of these sites is increasing, the securities concern is also increase. Please beware before disclosing you personal data on the social networking sites. Some security tips can be found &lt;a href="http://www.us-cert.gov/cas/tips/ST06-003.html"&gt;here&lt;/a&gt;. &lt;/p&gt;&lt;div class="blogger-post-footer"&gt;&lt;img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7292128642496133099-1184680190096427017?l=somkar.blogspot.com'/&gt;&lt;/div&gt;</content><link rel='replies' type='application/atom+xml' href='http://somkar.blogspot.com/feeds/1184680190096427017/comments/default' title='Post Comments'/><link rel='replies' type='text/html' href='https://www.blogger.com/comment.g?blogID=7292128642496133099&amp;postID=1184680190096427017' title='2 Comments'/><link rel='edit' type='application/atom+xml' href='http://www.blogger.com/feeds/7292128642496133099/posts/default/1184680190096427017'/><link rel='self' type='application/atom+xml' href='http://www.blogger.com/feeds/7292128642496133099/posts/default/1184680190096427017'/><link rel='alternate' type='text/html' href='http://somkar.blogspot.com/2009/05/why-social-networking-sites-gaining.html' title='Why Social Networking Sites gaining Popularity?'/><author><name>Omkar Singh</name><uri>http://www.blogger.com/profile/02226583489163295452</uri><email>omkar.pune@gmail.com</email><gd:extendedProperty xmlns:gd='http://schemas.google.com/g/2005' name='OpenSocialUserId' value='07066598564130479392'/></author><thr:total xmlns:thr='http://purl.org/syndication/thread/1.0'>2</thr:total></entry><entry><id>tag:blogger.com,1999:blog-7292128642496133099.post-1403605167608248655</id><published>2008-12-30T23:07:00.002+05:30</published><updated>2008-12-31T10:30:33.225+05:30</updated><category scheme='http://www.blogger.com/atom/ns#' term='Technical'/><category scheme='http://www.blogger.com/atom/ns#' term='IM'/><title type='text'>Login Sequence in yahoo 9</title><content type='html'>&lt;p class="MsoNormal"&gt;In yahoo 9, there is change in the login sequence. In new version yahoo introduced a two stage login process. This means, instead of directly connecting to yahoo server to validate username and password, in first stage, yahoo 9 client sends a HTTP GET request to yahoo login servers 68.180.216.31 (vcs1.msg.vip.sp1.yahoo.com or vcs1.msg.yahoo.com) and 76.13.14.40 (vcs2.msg.vip.ac4.yahoo.com or vcs2.msg.yahoo.com). The yahoo login server responds with a HTTP 200 OK response. This HTTP 200 OK packet contains a yahoo server IP address with key CS_IP_ADDRESS. This CS_IP_ADDRESS can be any yahoo server from its long list.&lt;/p&gt;  &lt;p class="MsoNormal"&gt;&lt;span style="mso-spacerun:yes"&gt; &lt;/span&gt;In stage 2 yahoo 9 clients connects to any of the yahoo server on port 5050, to complete its login process and for further communication. The stage 2 is same as the login sequence what yahoo was having in previous versions. &lt;span style="mso-spacerun:yes"&gt; &lt;/span&gt;The only difference is in yahoo 9 the client can connect to yahoo server which it got in previous stage at runtime. With the new version yahoo increase the number of its servers. The complete list of new yahoo servers can be found &lt;a href="http://www.viprasys.com/vb/f25/ygamer-5-3-new-update-12-nov-2008-a-8713/index2.html"&gt;here&lt;/a&gt;. &lt;span style="mso-spacerun:yes"&gt; &lt;/span&gt;&lt;/p&gt;&lt;div class="blogger-post-footer"&gt;&lt;img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7292128642496133099-1403605167608248655?l=somkar.blogspot.com'/&gt;&lt;/div&gt;</content><link rel='replies' type='application/atom+xml' href='http://somkar.blogspot.com/feeds/1403605167608248655/comments/default' title='Post Comments'/><link rel='replies' type='text/html' href='https://www.blogger.com/comment.g?blogID=7292128642496133099&amp;postID=1403605167608248655' title='0 Comments'/><link rel='edit' type='application/atom+xml' href='http://www.blogger.com/feeds/7292128642496133099/posts/default/1403605167608248655'/><link rel='self' type='application/atom+xml' href='http://www.blogger.com/feeds/7292128642496133099/posts/default/1403605167608248655'/><link rel='alternate' type='text/html' href='http://somkar.blogspot.com/2008/12/login-sequence-in-yahoo-9.html' title='Login Sequence in yahoo 9'/><author><name>Omkar Singh</name><uri>http://www.blogger.com/profile/02226583489163295452</uri><email>omkar.pune@gmail.com</email><gd:extendedProperty xmlns:gd='http://schemas.google.com/g/2005' name='OpenSocialUserId' value='07066598564130479392'/></author><thr:total xmlns:thr='http://purl.org/syndication/thread/1.0'>0</thr:total></entry><entry><id>tag:blogger.com,1999:blog-7292128642496133099.post-1834887049120025365</id><published>2008-09-21T02:56:00.001+05:30</published><updated>2008-09-21T22:38:14.529+05:30</updated><category scheme='http://www.blogger.com/atom/ns#' term='Technical'/><category scheme='http://www.blogger.com/atom/ns#' term='Google'/><category scheme='http://www.blogger.com/atom/ns#' term='IM'/><title type='text'>Security and Privacy in Instant Messaging</title><content type='html'>In the recent time there is huge gain in popularity of Instant Messenger services. In fact there is over 1 billions of messages transfer each day using instant messaging (IM). With increase in popularity, the instant messenger networks are moving towards encrypted communication from plain communication.&lt;br /&gt;&lt;br /&gt;Many of IM software send the conservation as the plain text over the internet. This allows anybody to monitor your conservation. There are many tools available on the internet by which anybody can see your instant messages. Many of the user, unknowing all these security concern, communicate private/confidential information through instant messages. This gives the hacker a chance of misuse the private information which can cause the disasters.&lt;br /&gt;&lt;br /&gt;Now the use of instant messengers is well accepted and encouraged in the corporate world as the formal communication as it provides a synchronize communication mechanism which is faster than email and cheaper than phones. With the use of instant messaging in an organization, the security has become a concern. This security concern is motivating the IM service provider to provide a secure communication.&lt;br /&gt;&lt;br /&gt;There are many add-on tools/utilities available in the market which helps in achieving the secure instant messaging. These utilities not only encrypt and authenticate messages but also the file transfers.&lt;br /&gt;&lt;br /&gt;Even though the increase in use and popularity of IM indicates the need of secure IM communication, there are only few IM networks like &lt;a href="http://somkar.blogspot.com/2008/08/why-it-is-difficult-to-block-skype.html"&gt;Skype&lt;/a&gt;, Google talk, AOL etc. which provides the security by encrypting the communication. May be in recent future we will see all networks going for secure communication.&lt;div class="blogger-post-footer"&gt;&lt;img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7292128642496133099-1834887049120025365?l=somkar.blogspot.com'/&gt;&lt;/div&gt;</content><link rel='replies' type='application/atom+xml' href='http://somkar.blogspot.com/feeds/1834887049120025365/comments/default' title='Post Comments'/><link rel='replies' type='text/html' href='https://www.blogger.com/comment.g?blogID=7292128642496133099&amp;postID=1834887049120025365' title='1 Comments'/><link rel='edit' type='application/atom+xml' href='http://www.blogger.com/feeds/7292128642496133099/posts/default/1834887049120025365'/><link rel='self' type='application/atom+xml' href='http://www.blogger.com/feeds/7292128642496133099/posts/default/1834887049120025365'/><link rel='alternate' type='text/html' href='http://somkar.blogspot.com/2008/09/security-and-privacy-in-instant.html' title='Security and Privacy in Instant Messaging'/><author><name>Omkar Singh</name><uri>http://www.blogger.com/profile/02226583489163295452</uri><email>omkar.pune@gmail.com</email><gd:extendedProperty xmlns:gd='http://schemas.google.com/g/2005' name='OpenSocialUserId' value='07066598564130479392'/></author><thr:total xmlns:thr='http://purl.org/syndication/thread/1.0'>1</thr:total></entry><entry><id>tag:blogger.com,1999:blog-7292128642496133099.post-1277018604416548193</id><published>2008-08-24T17:18:00.000+05:30</published><updated>2008-08-24T17:44:41.904+05:30</updated><category scheme='http://www.blogger.com/atom/ns#' term='Technical'/><title type='text'>USB Popularity</title><content type='html'>&lt;a href="http://4.bp.blogspot.com/_1Hmf_9ruOWo/SLFNAqZWhDI/AAAAAAAAABc/qymoV7ffUJ8/s1600-h/usb.jpg"&gt;&lt;img id="BLOGGER_PHOTO_ID_5238052515384558642" style="FLOAT: left; MARGIN: 0px 10px 10px 0px; CURSOR: hand" alt="" src="http://4.bp.blogspot.com/_1Hmf_9ruOWo/SLFNAqZWhDI/AAAAAAAAABc/qymoV7ffUJ8/s200/usb.jpg" border="0" /&gt;&lt;/a&gt; In the recent time there is a huge, visible increase in popularity of USB. USB which was initially developed to support PC peripherals, is now extended its existence in digital world by devices like digital camera, iPod, mobile phones etc. Mature technology, backward-compatible, cheap single interface, Easy plug and play etc. are some of the reasons which boosted its popularity.&lt;br /&gt;&lt;br /&gt;USB has tree like structure called tired-star topology, which provides the flexibility to connect multiple devices(up to 127), at the same time. The devices includes the compound devices (device comprised of a function device and at least one hub). USB provide the freedom to attach devices at any time with least effort as USB devices are automatically recognized and configured.&lt;br /&gt;Another feature of USB contributing to its popularity, is its power management, which enables the devices to draw power from USB or from an attached self powered hub. With introduction of each new standard, there was significant increase in data transfer rates with full backward compatibility. Therefore currently the USB support the 3 different data transfers rates 1.5 Mbps(low speed), 12 Mbps(medium speed) and 480 Mbps(high speed).&lt;br /&gt;&lt;br /&gt;As evidenced of USB popularity, many extensions of the USB, like the OTG (On-The-Go), are available in the market. Also many companies are combining the USB with other devices to provide the flexibility to the user. Currently we can see many technologies build over USB like wireless, Bluetooth etc. It is the popularity of USB stick which eliminated the floppy drive from the computer. The popularity can be guessed easily from the fact that there are more than 2 millions of USB devices currently in use, around the world.&lt;br /&gt;&lt;br /&gt;&lt;a href="http://2.bp.blogspot.com/_1Hmf_9ruOWo/SLFNkZ3ZFWI/AAAAAAAAABk/gGSODGx39uk/s1600-h/usb_interface_425%5B1%5D.jpg"&gt;&lt;img id="BLOGGER_PHOTO_ID_5238053129422443874" style="FLOAT: left; MARGIN: 0px 10px 10px 0px; CURSOR: hand" alt="" src="http://2.bp.blogspot.com/_1Hmf_9ruOWo/SLFNkZ3ZFWI/AAAAAAAAABk/gGSODGx39uk/s200/usb_interface_425%5B1%5D.jpg" border="0" /&gt;&lt;/a&gt;The popularity of USB and the increase in file size capability of digital media, motivated the development of USB 3.0 standard. The USB 3.0, which is also known as SuperSpeed USB, is expected to provide a speed of the 10 times faster than current USB 2.0. It means the SuperSpeed USB will transfer data at the rate of 4.8Gb/s compare to 480Mb/s of USB 2.0. This will provide fast synchronization of data consumer devices and mobile which are now capable of holding more than 25GB file.&lt;div class="blogger-post-footer"&gt;&lt;img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7292128642496133099-1277018604416548193?l=somkar.blogspot.com'/&gt;&lt;/div&gt;</content><link rel='replies' type='application/atom+xml' href='http://somkar.blogspot.com/feeds/1277018604416548193/comments/default' title='Post Comments'/><link rel='replies' type='text/html' href='https://www.blogger.com/comment.g?blogID=7292128642496133099&amp;postID=1277018604416548193' title='1 Comments'/><link rel='edit' type='application/atom+xml' href='http://www.blogger.com/feeds/7292128642496133099/posts/default/1277018604416548193'/><link rel='self' type='application/atom+xml' href='http://www.blogger.com/feeds/7292128642496133099/posts/default/1277018604416548193'/><link rel='alternate' type='text/html' href='http://somkar.blogspot.com/2008/08/usb-popularity.html' title='USB Popularity'/><author><name>Omkar Singh</name><uri>http://www.blogger.com/profile/02226583489163295452</uri><email>omkar.pune@gmail.com</email><gd:extendedProperty xmlns:gd='http://schemas.google.com/g/2005' name='OpenSocialUserId' value='07066598564130479392'/></author><media:thumbnail xmlns:media='http://search.yahoo.com/mrss/' url='http://4.bp.blogspot.com/_1Hmf_9ruOWo/SLFNAqZWhDI/AAAAAAAAABc/qymoV7ffUJ8/s72-c/usb.jpg' height='72' width='72'/><thr:total xmlns:thr='http://purl.org/syndication/thread/1.0'>1</thr:total></entry><entry><id>tag:blogger.com,1999:blog-7292128642496133099.post-7531218165778098905</id><published>2008-08-13T01:35:00.000+05:30</published><updated>2008-09-21T04:37:38.889+05:30</updated><category scheme='http://www.blogger.com/atom/ns#' term='General'/><category scheme='http://www.blogger.com/atom/ns#' term='Google'/><title type='text'>Advantages of "Innovation time off"</title><content type='html'>Google deploy a technique called “Innovation time off”, to encourage its employee to spend 20% working(one day of their week) on the work they like. Products like Gmail, Google News, Orkut, AdSense etc are the results of this technique. They claim, about half of their new products are result of this 20% free time. &lt;span class="blsp-spelling-error" id="SPELLING_ERROR_0"&gt;Isn&lt;/span&gt;’t sound interesting, getting 50% of return for an investment of 20%.&lt;br /&gt;&lt;br /&gt;Today, most of the organizations are providing good facilities and good environment, to get best from their employees. But instead of providing facilities &lt;span class="blsp-spelling-error" id="SPELLING_ERROR_1"&gt;isn&lt;/span&gt;’t good idea to provide the one project of employee’s interest, to get best from them. Also this technique will help to utilize the bench period of the employees, as in the free time each employee will be busy with a project. The project which is result of his thought process.&lt;br /&gt;&lt;br /&gt;In a regular project, contribution of a junior level resource, in designing phase is very minimal as designing is normally performed by senior members of the team. During 20% time, employee will work on the projects ignited by his own idea, therefore he gets a good chance to design his won idea/project. This will help to increase the creativity of the employees.&lt;br /&gt;&lt;br /&gt;In software industries, work satisfaction, is one of the major factor of Attrition. Most of employees, I found, are not happy with the project they are doing. “Innovation time off” ensure that at every time, each resource is engage, at least in one of the project of his interest. Thus it must be very effect to retain the best talent in the organization.&lt;br /&gt;&lt;br /&gt;Besides all above mentioned advantages, there are some challenges in front of organization, in implementing the “Innovation time off” technique. One of the major problem is the ‘schedule tightness’, but at least organization can start with providing one afternoon (10%) of free time, to their employee, to work on projects of their choice.&lt;div class="blogger-post-footer"&gt;&lt;img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7292128642496133099-7531218165778098905?l=somkar.blogspot.com'/&gt;&lt;/div&gt;</content><link rel='replies' type='application/atom+xml' href='http://somkar.blogspot.com/feeds/7531218165778098905/comments/default' title='Post Comments'/><link rel='replies' type='text/html' href='https://www.blogger.com/comment.g?blogID=7292128642496133099&amp;postID=7531218165778098905' title='3 Comments'/><link rel='edit' type='application/atom+xml' href='http://www.blogger.com/feeds/7292128642496133099/posts/default/7531218165778098905'/><link rel='self' type='application/atom+xml' href='http://www.blogger.com/feeds/7292128642496133099/posts/default/7531218165778098905'/><link rel='alternate' type='text/html' href='http://somkar.blogspot.com/2008/08/advantages-of-innovation-time-off.html' title='Advantages of &quot;Innovation time off&quot;'/><author><name>Omkar Singh</name><uri>http://www.blogger.com/profile/02226583489163295452</uri><email>omkar.pune@gmail.com</email><gd:extendedProperty xmlns:gd='http://schemas.google.com/g/2005' name='OpenSocialUserId' value='07066598564130479392'/></author><thr:total xmlns:thr='http://purl.org/syndication/thread/1.0'>3</thr:total></entry><entry><id>tag:blogger.com,1999:blog-7292128642496133099.post-4902456138653607306</id><published>2008-08-06T01:25:00.000+05:30</published><updated>2008-08-16T23:43:21.405+05:30</updated><category scheme='http://www.blogger.com/atom/ns#' term='Technical'/><title type='text'>Why it is difficult to block skype protocol?</title><content type='html'>&lt;p&gt;&lt;br /&gt;In recent some years the popularity and usability of skype increase rapidly among the user, thanks to its ability to negotiate firewalls, network address translation and other barriers. This ability of skype has made the life of system administrator more miserable and raised some security concern. How difficult is to block the skype can be easily guess by the fact that even with the huge popularity, till date, there are very few applications or firewalls which support blocking of skype.&lt;br /&gt;&lt;br /&gt;&lt;strong&gt;Why it is difficult to block skype protocol?&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;1&gt;    Random port:&lt;br /&gt;&lt;/strong&gt;A Skype client randomly choose the port number, including the HTTP port (80) and HTTPS port(443), to listen for a TCP and a UDP connection. Therefore any rule to block traffic on any particular port does not work for skype.&lt;br /&gt;&lt;br /&gt;&lt;strong&gt;2&gt;    Host Cache:&lt;br /&gt;&lt;/strong&gt;Skype Client builds and refreshes the host cache (HC) regularly। This host cache contains the list of super node IP address and port which act as skype server. As the Host Cache entries keeps on changing, any rule based on IP address also does not work.&lt;/p&gt;&lt;p&gt;&lt;br /&gt;&lt;strong&gt;3&gt;    Encryption&lt;/strong&gt; &lt;strong&gt;:&lt;br /&gt;&lt;/strong&gt;Skype uses AES (Advanced Encryption Standard) with 256 bit encryption.  Because of 256 bit encryption, the number of possible keys, to actively encrypt the data in each Skype call or instant message,  are huge( 1.1 x 1077). Skype uses 1536 to 2048 bit RSA to negotiate symmetric AES keys.&lt;/p&gt;&lt;p&gt;&lt;br /&gt;&lt;strong&gt;4&gt;    Nat and Firewall:&lt;br /&gt;&lt;/strong&gt;Skype Client uses a variation of the STUN (Simple Traversal of UDP the NAT) and TURN (Traversal Using Relay NAT)  protocols to determine the type of NAT and firewall it is behind. This ensure that it reach the internet.&lt;br /&gt;&lt;br /&gt;&lt;strong&gt;How to block skype?&lt;/strong&gt; &lt;/p&gt;&lt;p&gt;So is there any way to block the skype protocol in a network? Yes, the only way to achieve it by inspecting the packets containing the skype traffic and identifying the skype signature. But as the skype is a encrypted protocol, it is not very easy to do so even by packet inspection. The only place it can be identify and block, is at the time of login. Once the login is over it is very difficult to distinguish between packets of the skype or other HTTPS packets.&lt;/p&gt;&lt;div class="blogger-post-footer"&gt;&lt;img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7292128642496133099-4902456138653607306?l=somkar.blogspot.com'/&gt;&lt;/div&gt;</content><link rel='replies' type='application/atom+xml' href='http://somkar.blogspot.com/feeds/4902456138653607306/comments/default' title='Post Comments'/><link rel='replies' type='text/html' href='https://www.blogger.com/comment.g?blogID=7292128642496133099&amp;postID=4902456138653607306' title='1 Comments'/><link rel='edit' type='application/atom+xml' href='http://www.blogger.com/feeds/7292128642496133099/posts/default/4902456138653607306'/><link rel='self' type='application/atom+xml' href='http://www.blogger.com/feeds/7292128642496133099/posts/default/4902456138653607306'/><link rel='alternate' type='text/html' href='http://somkar.blogspot.com/2008/08/why-it-is-difficult-to-block-skype.html' title='Why it is difficult to block skype protocol?'/><author><name>Omkar Singh</name><uri>http://www.blogger.com/profile/02226583489163295452</uri><email>omkar.pune@gmail.com</email><gd:extendedProperty xmlns:gd='http://schemas.google.com/g/2005' name='OpenSocialUserId' value='07066598564130479392'/></author><thr:total xmlns:thr='http://purl.org/syndication/thread/1.0'>1</thr:total></entry></feed>