I am trying to connect two computers using ssh via internet.
One is desktop and another is laptop. They both are running debian wheezy with ssh installed.

At first, let me mention how I do for internet connection.
To go online on the Desktop or Laptop, I enable data packet and wifi hotspot of my android phone.
Then I make computer receives wifi from android and enjoy internet connection.

In my testing, I can do "remote login" each other if both computers are receiving same wifi from only one andorid phone.
It can be ok even if data packet on the android phone is disabled.

But, if I arrange two computers receive different wifi respectively from two android phones with data packets enabled,
I can't do "remote login". The message I get is

(Laptop's hostname is just debian and Desktop's hostname is dbndst)

How can I do "remote login" between them using two different phone.
(Note: using phone for internet connection is only one option available for me)

You obviously have to place the ip there instead of the hostname...

Is the ssh-server package installed? Have you created and exchanged the appropriate keys (RSA, for instance) between the devices involved? If not, do so

yes, I have ssh-server package installed.
and also I created and exchanged the appropriate keys (RSA, for instance).
but it still doesn't work.

and I also tried with ip instead of hostname.
but it still doesn't work.

anyway, thanks for your replies...

Can you ping the devices from each other (i.e. is there a network connection between them)?

Try the telnet command ... if you can't get a connection, then it's a network problem.

hornestly, I don't know how to ping between devices(Phones).
no connection between them. they have just internet connection sparately using data packet enabled.

telnet command doesn't work too. so it is a network problem?

in my testing, it seems that SSH is available only on the same wifi network.
but I don't think so...because SSH is mentioned as to connect to remote computer through internet.
It says "through internet", not "on the same wifi network".

anyhow, I am learning more about ping and telnet and trying again ping and telnet command.