Indirect Data Forwarding Tunnel

>> Indirect data forwarding is needed only in case there is no user-plane available between Source eNB to Target eNB/Target-Rnc.

>> Indirect tunnel is created between
Source eNB - Source SGW - Target SGW - Target eNB.

>> Used for forwarding the buffered traffic from old-eNB, Here MME can select a new SGW to forward this traffic.
i.e Source eNB -- New SGW - Target SGW - Target eNB.
The New SGW being selected acts just a next-hop router.

The Mother India

Just finished reading a book on Indira Gandhi. I always liked her and appreciated her as one of the finest and the courageous leader our country ever had. Almost all(not all) her decisions were justified by our country situation and necessity at that time. She has always been my role model since the time I got my little brain functioning.

Given the power and chance to rewrite history I would like to change just one instance i.e. rewrite the page of 31st Oct 1984, the day Indira took her last breath, the day she got assassinated. I am least bothered or feel upset losing any political leader whether it is Gandhi or anybody, but have an emotional and compassionate feeling for losing her. To me, losing her hurts like losing my own mother.

Perhaps she felt the steps of coming death. "If I die today, every drop of my blood will invigorate the nation"- this was the last speech she gave on 30th Oct ’84.

I observe this date as analogous to Muharram for us Indians. She died protecting the integrity of our nation. 31st Oct- Rashtriya Sankalp Diwas (National Integration Day) that we observe every year, this name conveys everything.

 

Rest in Peace Mother Indira. We will always miss you and your presence. You will live forever in our heart.

Changing your vnc password

Your VNC password is not the same as your UNIX password. Your VNC password must be set yourself. Your VNC password is encrypted within the passwd file in your .vnc directory. You can try to decrypt it (not recommended), or you can replace it (recommended).

Your VNC password and Unix logon password are two separate entities, so it's wise to choose a VNC password that is different than your Unix password. You can use the pwhelp command on Unix to generate a secure password for the VNC server.

To change the VNC password you must first delete the existing password file. From your home directory on Unix use the rm .vnc/passwd command to do this. Once you've accomplished that all you need to do is restart your Unix VNC session (use vncserver). The VNC server will recognize that you don't have a password set and prompt you for a new password. This enables you to keep an existing session active without having to restart the VNC server.

hostname% rm .vnc/passwd
remove .vnc/passwd? y
hostname% vncserver
You will require a password to access your desktops.

Password: ********
Verify: ******** 

Calculating Networks, Hosts and Broadcast Addresses

134.77.168.143 / 27

134.77.168.143
255.255.255.224

Binary 
134     .   77   .   168  .   143
10000110.01001101.10101000.10001111
255    .    255    .   255   .   224
11111111.11111111.11111111.11100000

Like Bits = Network
10000110.01001101.10101000.100 00000  /27
134     .   77   .   168  .  128
Broadcast = All Bits on
10000110.01001101.1010100.100 11111  /27
134     .   77    .  168 .   159

First Usable = First Bit on
10000110.01001101.1010100.100 00001  /27
134     .   77   .   168  .  129
Last Usable
10000110.01001101.1010100.100 11110  /27
134     .   77   .   168 .     158

.128 64 32 16 8 4 2  1
.X     X  X  X X X X X

Mail Tsunami

A tempestuous email thread, visualized to be unscathed but resulting in a useless loss of  resources. It's not like that I have never seen such email threads. A long time ago at some point, I also used to be a part of these chains. But nevertheless, this thread was really different involving thousands of people and was really tempting for each one to revert. It was tantalizing for me too but I preferred to be on shore.

Last week an email was sent which was intended only for a small set of managers to encourage their staffs to complete an online training by the end of the month. But, in a move reminiscent of other email storms*, the unnamed sender mistakenly included a "xyz_training" mailing list that contained the addresses of thousands of employees – presumably without a restricted senders' list.

Now while the managers were discussing if the training was relevant to their staff (keeping the mailing list in the 'To:' line), someone triggered the storm by asking to be removed from the mailing list. It gathered momentum, mainly from the Indian offices, with lots of 'unsubscribe' and 'me-too' requests, ultimately nettled by enormous vague mails popping up the inbox,most of the employees requested not to "reply all" ,although they themselves were helping the thread to proliferate.It ended up in a complete plethora of chain mails.

Just when it looked like the storm had ended, it quickly picked up the pace again as employees in the US opened their mails in the morning.

Now I made some calculation in this mayhem.

Lets assume there are approximately 35,000 people on that thread.

A rough approximation of 270 minimum new Useless emails in my inbox that day.
i.e. 35,000 x 270 ~= 9.5 million emails worth of traffic.
Going by a conservative 50 KB per email.
That’s 475 GB worth of junk on the server.
Going by the past trend(from when this last happened), that’s translates to > $600,000 for the company.

The easy way to avoid these storms is to just ignore those mails that you don’t find relevant instead of hitting the "Reply-All" button or if you find it to be too much intractable, then choose the "Ignore" button and you will not be getting any mails further from that source.

Take precautions while broadcasting a mail to a large audience, keep the group-mailer-id in Bcc field and in the end of mail body mention the Bcc:group-mailed-id to let people know which audience is being targeted.

for-else loop in python

This is a very interesting constructor in python and I m quite impressed with this. A very intelligent way to combine a loop with a condition.

Example 1:
foo = [ 1, 2, 3 ]
for i in foo:
    print "inside for loop with value %d"  %(i)
else:
   print "inside else condition %d" %(i)

Output:
inside for loop with value 1
inside for loop with value 2
inside for loop with value 3
inside else condition 3

Example 2:
foo = [ 1, 2, 3 ]
for i in foo:
     if i = = 2:
           print "inside for loop with value %d"  %(i)
           break
else:
   print "inside else condition %d" %(i)

Output:
inside for loop with value 2

Example 3:
foo = [ 1, 2, 3 ]
for i in foo:
     if i = = 2:
           print "inside for loop with value %d"  %(i)
           continue
else:
   print "inside else condition %d" %(i)

Output:
inside for loop with value 2
inside else condition 3

Example 4:
foo = [ 1, 2, 3 ]
for i in foo:
     if i = = 3:
           print "inside for loop with value %d"  %(i)
           break
else:
   print "inside else condition %d" %(i)

Output:
inside for loop with value 3


for-else loop basically means "find some item in the iterable, else if none is found then look into else". In simple words, we can say when for loop gets fully exhausted(i.e; even after looking through all the iterables, if we don't find any item that can make us stop in those iterable item/s) then we should look into else condition. See Example 1 and 3.

If we find a condition in for loop, that can interrupt the for loop and terminate it earlier than it is supposed, then that means we have found something in for loop iterables that we were looking for(see Example 2 and 4), so there is no need to check into else condition.

Update (Dec 21, 2017): I guess I could simply summarize the for-ELSE loop as for-NoBreak loop. I mean when no BREAK is encounter in for loop, then only ELSE condition gets executed.

Update (Oct 12, 2020): Food for thoughts:

arr = [1, 2, 3, 4]

Question 1:

def f():

    for i in arr:

        if i == 4:

            break

        print(i, end=' ')

    else:

        print("else part")

Output: 1 2 3

Question 2:

def f():

    for i  in arr:

        pass

    else:

        print("else part")

Output: else

Windows 7’s Secret GodMade Power

Well, it’s not really a mode. To be clear, it’s not quite as magical or all-powerful as the name implies. It only organizes administrators work more efficiently by dumping all the controls in one central location for easy access. But I find it quite useful from time to time.

• Create a new folder anywhere (I set mine up on desktop)
• Rename the folder and paste in the following text: GodMode.{ED7BA470-8E54-465E-825C-99712043E01C}

Once that is done, the folder's icon will change to resemble a control panel and will contain all the control options. 

You can also choose to sell your system’s soul to the devil. “GodMode” is just a prefix and you can choose any word you like. For ex:  DevilMode.{ED7BA470-8E54-465E-825C-99712043E01C}