Saturday, December 31, 2011

Free Fast VPN proxies 2

For free proxies, Ultrasurf is still going strong, with constant updates to defeat censorship.

I do a lot of things on Amazon EC2, still free, including as a VPN server.  You can install a proxy server but ultimately you want to use other package other than browser, and that you want encryption.  A VPN may not be that slow because it uses UDP instead of TCP for transport.  Your own VPN is a lot faster than a public proxy, and you won't even feel it when browsing.

I install Openvpn myself.  But somebody should create an image with Openvpn securely installed, and all the configurations including the firewalls.  On the client side, we need someone to show us how to configure the VPN settings in Ubuntu elegantly so that you can easily switch between VPN and no VPN.  At the moment I kill the client whenever I need to switch and also set the DNS server.

I was surprised that TOR has documented how to use it as a VPN, directing all net traffic through it.  It's really not that bad when it's not at the peak hours, and you can have your private TOR node on EC2 to speed things up.

TOR is supposed to be hard to trace, unless you are big brother targeting someone known.  EC2 and other VPN and proxies suffers from more or less the same fate.  You don't know what the server does with your real IP.  Do you trust a company that you never heard of not to log your IP.  Or if they are small, nobody cares what they do.  It is possible that Amazon don't need to log any IP, because they are just hiring some hardware to you and you are responsible for the rules, like DMCA take downs.

Being untraceable, TOR IP's are usually banned when it matters.  EC2 and other small companies (probably using EC2 or other clouds) are not likely to be banned.  If you ban Amazon IP's, you are banning many services provided in the cloud.  Ec2 has the advantage that whenever you reboot, you have another IP (something like that). 

You need a credit/debit card to register for EC2 but a gift card will do.

Single cell phone multiple numbers (SIM method) 2

Still no carrier gives you a 2nd line with a different phone number.  But since the last post, things are a lot different.

If you buy direct from China, you have dual SIM card GSM phone for cheap, almost half that of my refurbished unlocked GSM phone many years ago.  They use those phones when people travel, it's much cheaper to just get another SIM from the convenient store than to do cross border roaming.  So you have two independent lines on a single phone, active all the time.  So you don't need any magic dual sim adapter unless you still don't want to part with your old GSM phone.

The other way is of course to buy a smart phone from China, and the only choice is Android.  Typically they have two sims because of the same reason above, and that it is popular to have one sim for voice, and another for broadband.  So you can say money when you don't need broadband all the time.  But both sim's are fully functionally.

The easiest, anywhere, is that you buy a smart phone.  In Android you have Google Voice app bundled, and you have the app in iPhones.  This app is pretty integrated in Android.  You can set that international calls will be using Google Voice alone.  Or any phone or text you send, you will be given the option of which number to use.  Or of course you can start GVoice to use the other number.  Also, you Google number is live all the time, direct to your phone.

You just need to signup for a Google Voice account and then ask for a new number.  It's free and "permanent" except for international calls.  But I think Google Voice is only available in US.  The only problem is that you use Google number as your main number.  I don't know if the app deals with a 2nd Google number.  Also, the rule is one mobile number for one Google Voice account.  You can redirect the numbers how you want it, but you need two mobile numbers to register for two accounts.

Skype is in disarray one year on.  It's probably because Skype has been using a sophisticated encryption intended for desktops years ago, and it's P2P, requiring extra processing than just the calls.  Typically they work but not well for the latest Android phones.

If you don't want to scrap your old phone because of the phone list, look if it supports Bluetooth.  Most does.  You just need to enable it and the new smart phones can import the phone list directly.

Friday, December 30, 2011

Home Security - cam, monitor and DVR (2)

Update to first part.

Wifi IP CAM didn't come down in price by a lot.  Direct from dhgate, it is closer to the $50 mark rather than the $100 mark.  You need a portable or desktop to record the video automatically.  That's not bad when you are sleeping or away from the desk.

DVR changes a lot since last time.   Even in the past, it doesn't make sense to have a CMOS CAM, turns the images into analogue signal, then the DVR re-digitize the image, compress and store it in hard disk.  Now, many people don't have NTSC and PAL anymore.  HDMI output for a CAM is too much.  So it only make sense to integrate the CAM with the DVR.

They became cheap small HD camcorders.  They are everywhere but they are just not for security CAM application.  You need overwrite or cycle recording.  So you never need to change "tapes" or SD cards.  The other very desirable feature is software motion detection - which saves a lot of storage space. 

There are one in dhgate exactly that.  They say it's for cars.  The price is not a lot more than $50.

My old DVR is going strong.  Similar things are still on sale but became more expensive now, a lot more than $50.  The output of my old CAM's are still NTSC.  HDMI output will be a lot more expensive.

Sunday, December 25, 2011

Printing on custom paper size in Ubuntu Linux

I'm so surprised that you cannot do that, not when your child is born, not when he graduate high school.  Somebody is waiting for that for his grandson birth announcement.

Basically the software package will allow any paper size.  But the printer typically has a list of papers, but no custom.

I was looking for something that avoid killing any of my brain cells.  But actually I think that's unsolvable.  I made a compromise, looking for a simple offset that I can specify to align things to where I want them.  No luck.

So I decided to solve it once an for all.  The problem:

Typically, you can select a paper on the printer that is not the same as the size on your package that you really want - real.  Typically the printer will place the real paper in the middle of the printer paper.  But for the printing, the real paper is aligned with the upper left corner of the printer paper.  So there is an offset when the real paper is not aligned at the corner, but the middle.

You can set the paper margin on your package to offset this.  Assuming the printer paper is larger than your real paper.  And that your real paper can fed through the printer.

top margin  = desired top margin
bottom margin  length printer - length real + desired bottom margin
right margin = (width printer - width real) / 2 + desired right margin
left margin = (width printer - width real) / 2 + desired left margin

Since you know the dimensions of papers anyway so it's not too bad by using the calculator.  You may even be able to set the software by a macro or script.

Friday, December 16, 2011

Managing EBS in EC2 for Ubuntu Linux

EBS in EC2 means virtual hard drive.  You are given one to start with, which is attached to your instant to run things.  This is exactly the boot drive where your OS is.  The free tier gives you 10GB EBS for free, but the free micro instant comes with only 8GB, which doesn't add up.

Sooner or later you need more disk space (or less).   You can change the size of the boot disk but very inconvenient.  First you create a snapshot (copy) of the boot drive.  From the snapshot you create a volume (new drive), with bigger space.  Then you stop your instant (computer), remove the boot drive and connect the new one. But you still see exactly the same old drive, because it's up to your installed OS to change the partition.  In addition, you can perform a lot of operation only on an unmounted drive.  So you may need another instant (like CDROM drive for the install disk) to modify your boot disk.  If you modify the partitions you can easily brick the whole disk.  Also, when you are working on EC2, you don't normally have GUI.

It's much easier to create a virtual empty disk drive, and mount as any directory on the file system that you desire.

First, you create a new volume on the EC2 control panel, with the capacity you needed.  Then you just attach it to your instant, running or not.  For Linux, the control panel will give you a new device name by default, such as /dev/sdf .  If you specify sdb, the extra disk space will be mounted to /mnt later by default.

The job of visualization is completed.  You need to configure your hard drives via your computer, i.e., your instant.

You need to start your instant (if not running) and then connect to it with ssh.  Then you need to "format" the new hard drive.

First check if the drive is there:
#sudo fdisk -l

You will get errors because these commands are not compatible with the file system or something else on the drive.

To "format"
#sudo mkfs -t ext4 /dev/sdf
The device name should be the same you have chosen at the control panel.  If you have chosen sdb for the lastest Ubuntu, all you have to is reboot at the control panel.  The drive will be mounted at /mnt.  Then you can setup directory links to this space as desired.

For any other device name or any other mount directory, you need to edit /etc/fstab.  And add the line:
/dev/sdf       /your/directory    auto    defaults,nobootwait,noatime     0       0
You can see that sdb is there already, to be mounted to /mnt.

In your boot drive, you should also create an empty directory /your/directory.  Then when you reboot via control panel, this empty directory will be replaced by the disk space of the new device.