What am I reading!!

Understanding SSL protocol

2011-08-29T12:14:00.000-07:00

http://www.cse.wustl.edu/~jain/cse473-05/ftp/i_isec/sld015.htm
http://www.ehow.com/facts_7842286_ssl-change-cipher-spec-protocol.html

installing linux

2011-07-12T14:57:00.000-07:00

Well i have installed linux servers before too, many. but this time the app requests are different. Esp the one with the remote desktop, got bored with vncviewer, wanted to installed something new. Found FreeNX for linux, wierd, yeh, as i have to open up a session id on localhost using the freenx client app, and then open up the same session id from my PC. Also facing issues with the serial console opening up for linux, centos. I am just wishing these problems dont linger for long, so as to push me to go back to Windows PC.

New link for cisco docs

2011-03-25T12:27:00.001-07:00

This is more for information :

cisco docs about protocols can now be found at :
http://docwiki.cisco.com/wiki/Internetworking_Basics

I liked the new outlook of cisco docs. :)

A new entry in Testing dictionary - DRIVE TESTING

2011-03-24T23:03:00.000-07:00

Oh Well, was reading an LTE forum discussions and bumped upon Drive Testing. Initial thought was is there something like that. Is the person sane in writing what he really means to write. Then i browsed through some more discussions on same topic and that cleared up my mind.

http://en.wikipedia.org/wiki/Drive_testing

Drive testing is a method of measuring and assessing the coverage, capacity and Quality of Service (QoS) of a mobile radio network

Read through wiki link to get to know more about it. As a simple test Engr and not on the Customer side, we may not do Drive testing but its always good to know.

My current assignment

2011-03-24T22:55:00.000-07:00

I am working on automation using OOPs and references with Perl. Exciting as I am getting to know more and better Perl coding standards. Using two design patterns, facade design pattern and Adapter design pattern. Interesting enough i always wanted to read about the design patterns and here I go. I am now using the design pattern to actually implement my new framework development for DPI feature. Guess that I might have used few other design patterns in my earlier projects not knowing the names of it. But well when you know what you are doing, things are much more exciting and interesting.
No more regression since last 4months. So much relieved. Its more of debugging or writing code now. And may be helping out in the SCM.

Its Strange I am back to square one again

2010-09-09T23:09:00.000-07:00

Huh! I wished never to return back to the regression testing again, after my tryst with Alcatel project making stable regression and making test suites. But well history repeats. I am back to a similar profile job but with new technology of 4G. Learning is key here and I am definitely prepared to perform above expectations. I wish I have time from my debugging and troubleshooting to spend time on technology reads and doc preparations. I wonder why this document preparation is such an effort when u really wish to do it but time doesn't allow you to.

which is better !!

2010-09-08T22:23:00.000-07:00

The data driven test framework or the test-driven test framework. Ofcourse I am in the middle of the the project. There is some framework code present and there is going to be development of new ones. Its not easy to decide which way to go - but Data driven surely looks much appeasing.
FYI,
Data Driven approach for test framework
Test driven approach for test framework

Any other suggestions are welcome!

An update!

2010-08-20T10:59:00.000-07:00

My current book is Perl Cookbook - oreilly. Its such a nice book, good to refresh if you know the basics of Perl. Also have some exercises to do. I wish I knew about this book early to make me more confident for my interviews. But its never late. I am still starting on this book, covering the related chapters. But I do wish to read each and every page of the book for a nice understanding on how different modules/code can be more optimized. Nice book.

Test Framework

2010-08-18T12:36:00.000-07:00

Lately i have been asked this question in my interview - how would you develop a test framework.

in my opinion the answer would be - first we need to make a model/architecture/flow diagram on how is our testcase be executed . I have worked on a few architectures before - like table-driven and data-driven framework.
Whichever we choose, we should have a clear idea about what will be our input/from where do we choose our input from and it should be such that the code doesn't change when the input changes.
Next would be to develop the core functionality on how to test. We may follow some simple algorithms or more complex algorithms, but the epicenter should be it is simple to read and understand. It should be modular with no hardcoded values and properly documented. The more modular approach we take like packaging, global functions or include files, more better the code. Also having a layered architecture helps in later project lifecycle, as we need to change only a few modules when the project requirement changes.

While discussing the code functionality of the software development, we need to take care of how our outputs are been verified. Mostly verification of one or more functionality takes into consideration some of the analysis tools to be developed which again should be easy to use. These analyzers may be in-house or the third-party, but the APIs to be used via these analyzers should be comprehensive, flexible, understandable and easy to use. Providing more than one way of passing parameters to these modules helps in expanding our test framework at a later stage.

Lastly we should make sure, how our testcase output is being reported. A nicer approach would be to put all our testcase in some test suite and then posting the output on the XML output or on a web-page-based interface.

Aboveall, the environment setup to execute any test should be easy. We should consider writing smaller shell/perl scripts to set the environment rather than using basic linux/unix command line.

Bumped on this useful link

2010-07-12T16:37:00.000-07:00

While preparing for my interview questions I bumped into this wonderful DB presented in form of a simple HTML page. http://kundansingh.com/interview/ . It may or may not have all the answers, but at least it can question you the basic of the interviews and to know if you really are prepared ??

cisco IOS Basic Config

2010-03-21T01:29:00.000-07:00

line console 0 : global configuration that changes the context to console configuration mode.
line vty 1st-vty 2nd-vty : global config that changes the context to vty configuration mode for the range of vty lines listed in the command.
login : linke (console and vty) configuration mode. Tells IOS to prompt for a password (no usrname).
password pass-value : line (console and vty) config mode. Lists the password required if the login command(with no other params) is configured.
interface type port-number : global command that changes the context to interface mode - ex. interface Fastethernet 0/1.
shutdown/ no shutdown :Interface commands that enables/disables the interface.
hostname name : global command that sets this switches hostname which is also used as the first part of the switch;s command prompt.
enable secret pass-value : global command that sets the automatically encrypted enable secret password. The password is used for any user to reach enable mode.
enable password pass-value : global command that sets the clear text enable password, which is used only when the enable secret password is not configured.
exit : moves back to the next higher mode in configuration mode.
end : exits configuration mode and goes back to enable mode from any of the configuration submodes.
ctrl+z : this is not a command, but rather a two-key combination that together do the same thing as the end command.
no debug all/ undebug all : enable mode EXEC command to disable all currently enabled debugs.
sow process : EXEC command that lists statistics about CPU utilization
terminal monitor : EXEC command that tells Cisco IOS to send a copy of all syslog messages, including debug messages, to the Telnet or SSH user who issues this command.
reload : enable mode EXEC command that reboots the switch or router.
copy from-location to-location : Enable mode EXEC command that copies files from one file location to another. Locations include the startup-config and running-config files, files on TFTP and RPC servers and flash memory.
copy running-config startup-config : Enable mode EXEC command that saves the active config, replacing the startup-config file used when the switch initialisex.
copy startup-config running-config : Enable mode EXEC command that merges the startup config file with the currently active config file in RAM.
show running-config : Lists the contents of the running-config file.
write erase/erase startup-config/erase nvram: : All three enable mode EXEC commands erase the startup config file.
setup : Enable mode EXEC command that places the user in setup mode, in which Cisco IOS asks the user for input on simple switch configuration.
quit : EXEC command that disconnects the user from the CLI session
show system: running-config : same as show running-config command
show startup-config : lists the contents of the startup-config file.
show nvram:startup-config/ show nvram: : same as show startup-config command.
enable : moves the user from user mode to enable(privileged)mode and prompts for an enable password if configured.
disable: moves the user from enable mode to user mode
configure terminal : enable mode command that moves the user into configuration command.

Important interview questions

2010-03-17T17:52:00.000-07:00

Below are few important interview questions which should be answered thoughtfully and diplomatically.

1. If I were to get feedback from your manager, what would be the three things he would say.
2. What are your three week points or what are the three improvement areas would you like to work on.
3. Tell me something about yourself.
4. What were the projects you have been engaged in.
5. Tell me brief about any project you liked the most and why.

Few of the video questions!!

2010-03-11T16:00:00.000-08:00

What is interlace scanning ?
What is progressive scanning ?
what is a pixel ?

What is HD and SD?

What is the maximum resolution in HD ?

more questions will follow !!!!!

Answers coming soon...

LAMP

2008-12-12T15:30:00.001-08:00

LAMP is an open source Web development platform that uses Linux as the operating system, Apache as the Web server, MySQL as the relational database management system and PHP as the object-oriented scripting language. (Sometimes Perl or Python is used instead of PHP.)

Because the platform has four layers, LAMP is sometimes referred to as a LAMP stack. Stacks can be built on different operating systems. Developers that use these tools with a Windows operating system instead of Linux are said to be using WAMP; with a Macintosh system, MAMP; and with a Solaris system, SAMP.

Domain Testing

2008-03-25T12:38:00.001-07:00

Domain testing is the practice of purchasing numerous available domain names and then exploiting a five-day grace period to determine which names would be profitable to own. The usual intent is to resell domain names likely to command high prices, although there are a number of ways that domain testers (sometimes called "domainers") make money from the practice.

As of March 2008, the cost to register a domain name is less than $10. Moreover, the registrant has five days, the add grace period (AGP), during which any money paid is refundable. Even a minimal transaction cost is waived. The AGP was originally intended to allow legitimate purchasers to return names registered in error (with a typo, for example) at a time when the cost per domain was considerably higher.

Domain tasters make money from the practice in a number of ways besides selling profitable domain names. In some cases, they repeatedly register and unregister domain names, in effect obtaining the use of the name for free. A domainer may also register a large number of domains and then set up Web sites containing nothing but advertising links. The domain taster monitors the activity on each site and keeps the domain names that generate the most clickthrough revenue or produce the highest clickthrough rates.

In volume, even pages that are only registered for the add grace period can make a great deal of money. According to Jay Westerdal, the CEO of Name Intelligence, Inc., a Google AdSense partner was making $3 million per month from the practice -- after Google's cut.

Read the rest of the definition for domain tasting at WhatIs.com, including the approaches being considered to make the practice unprofitable.

FTP - Active & Passive Mode

2007-05-21T11:17:00.000-07:00

It gives more reason to update, if someone reads n comments on the blog. So updating the blog henceforth with the useful links i find.

Read below to know the difference between the Active FTP and Passive FTP :

FTP Basics :

FTP is a TCP based service exclusively. There is no UDP component to FTP. FTP is an unusual service in that it utilizes two ports, a 'data' port and a 'command' port (also known as the control port). Traditionally these are port 21 for the command port and port 20 for the data port.

Active FTP:

In active mode FTP the client connects from a random unprivileged port (N > 1023) to the FTP server's command port, port 21. Then, the client starts listening to port N+1 and sends the FTP command PORT N+1 to the FTP server. The server will then connect back to the client's specified data port from its local data port, which is port 20.

From the server-side firewall's standpoint, to support active mode FTP the following communication channels need to be opened:

* FTP server's port 21 from anywhere (Client initiates connection)
* FTP server's port 21 to ports > 1023 (Server responds to client's control port)
* FTP server's port 20 to ports > 1023 (Server initiates data connection to client's data port)
* FTP server's port 20 from ports > 1023 (Client sends ACKs to server's data port)

The main problem with active mode FTP actually falls on the client side. The FTP client doesn't make the actual connection to the data port of the server--it simply tells the server what port it is listening on and the server connects back to the specified port on the client. From the client side firewall this appears to be an outside system initiating a connection to an internal client--something that is usually blocked.

Passive FTP:

In passive mode FTP the client initiates both connections to the server, solving the problem of firewalls filtering the incoming data port connection to the client from the server. When opening an FTP connection, the client opens two random unprivileged ports locally (N > 1023 and N+1). The first port contacts the server on port 21, but instead of then issuing a PORT command and allowing the server to connect back to its data port, the client will issue the PASV command. The result of this is that the server then opens a random unprivileged port (P > 1023) and sends the PORT P command back to the client. The client then initiates the connection from port N+1 to port P on the server to transfer data.

From the server-side firewall's standpoint, to support passive mode FTP the following communication channels need to be opened:

* FTP server's port 21 from anywhere (Client initiates connection)
* FTP server's port 21 to ports > 1023 (Server responds to client's control port)
* FTP server's ports > 1023 from anywhere (Client initiates data connection to random port specified by server)
* FTP server's ports > 1023 to remote ports > 1023 (Server sends ACKs (and data) to client's data port)

While passive mode FTP solves many of the problems from the client side, it opens up a whole range of problems on the server side. The biggest issue is the need to allow any remote connection to high numbered ports on the server. Fortunately, many FTP daemons, including the popular WU-FTPD allow the administrator to specify a range of ports which the FTP server will use.

The second issue involves supporting and troubleshooting clients which do (or do not) support passive mode. As an example, the command line FTP utility provided with Solaris does not support passive mode, necessitating a third-party FTP client, such as ncftp.

For examples please follow the link::

http://slacksite.com/other/ftp.html

Protocol RFC : http://www.faqs.org/rfcs/rfc959.html

What exactly is TCP Splicing

2007-02-23T01:40:00.000-08:00

I will put down my own words for the TCP Splice sometime later, when I have more time to give it a thought. For now, I have a good link which explaing about it for any Web Proxy device.

http://www2002.org/CDROM/refereed/627/

Diff between SSH SSL

2007-02-23T01:07:00.000-08:00

SSH (Secure Shell) and SSL (Secure Sockets Layer) can both be used to secure communications across the Internet. This page tries to explain the differences between the two in easily understood terms.

SSL was designed to secure web sessions; it can do more, but that's the original intent.

SSH was designed to replace telnet and FTP; it can do more, but that's the original intent.

SSL is a drop-in with a number of uses. It front-ends HTTP to give you HTTPS. It can also do this for POP3, SMTP, IMAP, and just about any other well-behaved TCP application. It's real easy for most programmers who are creating network applications from scratch to just grab an SSL implementation and bundle it with their app to provide encryption when communicating across the network via TCP.

SSH is a swiss-army-knife designed to do a lot of different things, most of which revolve around setting up a secure tunnel between hosts. Some implementations of SSH rely on SSL libraries - this is because SSH and SSL use many of the same encryption algorithms (i.e. TripleDES).

SSH is not based on SSL in the sense that HTTPS is based on SSL. SSH does much more than SSL, and they don't talk to each other - the two are different protocols, but have some overlap in how they accomplish similiar goals.

SSL by itself gives you nothing - just a handshake and encryption. You need an application to drive SSL to get real work done.

SSH by itself does a whole lot of useful stuff that allows users to perform real work. Two aspects of SSH are the console login (telnet replacement) and secure file transfers (ftp replacement), but you also get an ability to tunnel (secure) additional applications, enabling a user to run HTTP, FTP, POP3, and just about anything else THROUGH an SSH tunnel.

Without interesting traffic from an application, SSL does nothing. Without interesting traffic from an application, SSH brings up an encrypted tunnel between two hosts which allows you to get real work done through an interactive login shell, file transfers, etc.

Last comment: HTTPS does not extend SSL, it uses SSL to do HTTP securely. SSH does much more than SSL, and you can tunnel HTTPS through it! Just because both SSL and SSH can do TripleDES doesn't mean one is based on the other.

http://www.rpatrick.com/tech/ssh-ssl/

http://www.webopedia.com/TERM/S/SSL.html
a protocol

http://www.webopedia.com/TERM/S/SSH.html
a program for remote login

http://www.webopedia.com/TERM/T/TLS.html
a protocol

IGMP & other protocols to start with....

2005-05-13T10:55:00.000-07:00

Now from Monday on, will be working on the IGMP protocol testing. Wish I could have the required knowledge already, but no, I need lots of reading, little or more mind boggling sessions with myself and books and then will have to start off with my work. Really i shouldn't ever had stopped reading.

To start with here are some good sites to refer to about IGMP :

Internet Protocol Multicast
Explains IP multicast addressing, Internet Group Management Protocol, how multicast in Layer 2 switching works, defines multicast distribution trees, how multicast forwarding works, protocol-independent multicast, and more.

IP multicast control (IGMP)
Explains that IGMP is used for multicast traffic, the IGMP message structure including query, report, and leave group.

Multicasting
Explains what multicasting is used for, what is needed to use it, and the IGMP protocol used to provide multicasting.

And with above all a cool novice user link for newbies : Protocols

How long ..........

2005-05-13T10:39:00.001-07:00

" Woods are lovely dark and deep
I have many promisesto keep
And miles to go before I sleep
And miles to go before I sleep "

These few lines are never forgotten in my life. And again, I came across another such article, which talks " A CS profession should not stop reading". I sometimes think how much have I studied per day, after leaving my college. Yes, i do agree, i have learnt lots of things, and i know much more better than i do some years back, just after my college. But how much my effort went for the self-study.. May be NILL.....

I want again to resume to study, study of books, reading of novels (which was my favourite passtime), doing something (may be lots of things) to please myself. If these things die of my life, i would also certainly be dead soon, as i felt sometime back, before being among one of the bloggers till date. Now i have some direction to give to my dreams, my aspiration and my life.

Why i write this blog

2005-04-25T10:17:00.000-07:00

I am creating this blog with an intention to keep some important info handy. The things that i may wish to come back soon or again. It will be even more fantastic if i get some comments on them. I work on the area of telecom broadband development and testing based on C, C++, TCL/TK, perl , unix based (scripting)languges.