Paul's questions

From time to time and for various reasons, PyTTY loses connection to SSH sessions on my CentOS 7 server (PuTTY is buggy, SSH server is buggy, router has been rebooted, connection is dropped, cable pulled out etc). These abandoned sessions are a burden on the server and consume resources. Could the CentOS 7 SSH server be configured to automatically terminate any SSH session after 24 hours, regardless of session purpose and state?

Why regardless of session purpose and status? Because in my opinion it can sometimes be difficult to distinguish between a normal session and an abandoned session.

Test environment consists of a CSipSimple client, Asterisk server and a router with NAT. Formerly the equipment used UDP port 5060 and everything was good. Then I changed port number to 15000 in Asterisk, in router's forwarding rule and in client app. Now, when accessing the net from outside, client can register, but when it calls some extension, Asterisk complains about inability to create DAHDI channel. When client is in the LAN, calls are working.

What went wrong? I changed only control port number.

Update

At first place I need to mention that Asterisk always complains about inability to create DAHDI channel when I am calling extension number 100, no matter whether the voice works or not. So, this error message could be ignored.

Now, the differing tails of verbose call logs:

Mobile client registered over 3G, no sound (call, pickup, timeout):

-- SIP/103-00000001 answered SIP/101-00000000
   > 0x7fda800295a0 -- Probation passed - setting RTP source address to 192.168.1.100:5062

That's all. No further messages.

Mobile client registered over WiFi, sound works (call, pickup, conversation, hangup):

  -- SIP/103-00000003 answered SIP/101-00000002
     > 0x7fda88026620 -- Probation passed - setting RTP source address to 192.168.1.100:5062
     > 0x7fda78013fb0 -- Probation passed - setting RTP source address to 192.168.1.112:4000
     > 0x7fda78013fb0 -- Probation passed - setting RTP source address to 192.168.1.112:4000
  -- Executing [h@macro-dial-one:1] Macro("SIP/101-00000002", "hangupcall,") in new stack
  -- Executing [s@macro-hangupcall:1] GotoIf("SIP/101-00000002", "1?theend") in new stack
  -- Goto (macro-hangupcall,s,3)
  -- Executing [s@macro-hangupcall:3] ExecIf("SIP/101-00000002", "0?Set(CDR(recordingfile)=)") in new stack
  -- Executing [s@macro-hangupcall:4] Hangup("SIP/101-00000002", "") in new stack
== Spawn extension (macro-hangupcall, s, 4) exited non-zero on 'SIP/101-00000002' in macro 'hangupcall'
== Spawn extension (macro-dial-one, h, 1) exited non-zero on 'SIP/101-00000002'
== Spawn extension (macro-dial-one, s, 43) exited non-zero on 'SIP/101-00000002' in macro 'dial-one'
== Spawn extension (macro-exten-vm, s, 9) exited non-zero on 'SIP/101-00000002' in macro 'exten-vm'
== Spawn extension (from-internal, 103, 2) exited non-zero on 'SIP/101-00000002'

I've installed GUI on CentOS 6.5 with

yum groupinstall basic-desktop desktop-platform x11 fonts

but now when I attempt to use GUI Package Manager (Add/Remove software) to install packages, it asks me for root password and does not accept sudo user password. How to cure this behaviour?

I can install packages with sudo yum install in a normal way.

I've installed Asterisk Now with PreePBX from bootable CD to a VirtualBox machine.

Then I updated through FreePBX all the modules available for update and noticed a strange behaviour:

After I attempt to connect to Asterisk with PhonerLite client the virtual machine stops responding to TCP/UDP connections. I can't access it through SSH console, FreePBX does not respond through network.

I can log on locally, start lynx and enter FreePBX in text mode. Also I can only log in locally and reboot the machine. After that everything is ok until I attempt to connect to Asterisk.

There is no dependence on Virtualbox networking mode.

I am trying to install Phusion Passenger module for Nginx. There was Nginx installed in /usr/sbin/nginx. The installer gem downloaded Nginx sources and compiled them with Passenger support into /opt/nginx/sbin/nginx. I copied this file into /usr/sbin/nginx.

So currently I am in doubt which Nginx is running and which config file I should edit.

Is there some way to determine the location of actually used Nginx and which configuration file does it use?

Today I tried to connect two laptop computers, both having Gigabit Ethernet NICs, both with Windows 7, with straight cable cat 5e. The cable is ca 50 cm long so the category 5e should be enough.

I've set static IP addresses for both and tested them through SMB, HTTP and FTP.

The response of HTTP and FTP is instant, but going to SMB share takes too long. Each folder change takes ca 2 minutes.

And finally, the real speed of FTP (Microsoft IIS to FAR manager) was ca 219 mbit/s (4053265652 bytes file has been transfered in 141 sec).

Why the connection is so slow and why it takes forever to browse through SMB share?

Update especially for mrdenny

Copying of the file over 100 Mbit/s LAN with router didn't show any significant difference between SMB and FTP download speed:

SMB: 349 seconds (88,6 Mbit/s) FTP: 345 seconds (89,6 Mbit/s)

Update

I discovered an iperf tool and it shows me pure TCP network performance without involving HDDs.

Yes, it shows much faster network speed, but results vary from one test to other and sometimes the tool shows an extreme low speed, so I can't trust it:

iperf, straight 1m cable, static IPv4 addresses:

10.3 sec   683 MBytes   558 Mbits/sec
10.0 sec   740 MBytes   621 Mbits/sec
10.4 sec  19.2 MBytes  15.5 Mbits/sec
10.0 sec   553 MBytes   464 Mbits/sec
10.0 sec   635 MBytes   532 Mbits/sec
10.0 sec   694 MBytes   582 Mbits/sec
10.0 sec   661 MBytes   554 Mbits/sec
10.5 sec  20.0 MBytes  16.0 Mbits/sec
12.3 sec   600 MBytes   410 Mbits/sec
256.0 sec   526 MBytes  17.2 Mbits/sec
10.0 sec   807 MBytes   677 Mbits/sec
10.1 sec  21.1 MBytes  17.5 Mbits/sec
10.3 sec  16.6 MBytes  13.6 Mbits/sec
10.1 sec  22.9 MBytes  19.0 Mbits/sec
10.1 sec  20.8 MBytes  17.2 Mbits/sec
10.0 sec   679 MBytes   569 Mbits/sec
10.0 sec   597 MBytes   500 Mbits/sec
10.0 sec   806 MBytes   675 Mbits/sec
10.0 sec   751 MBytes   629 Mbits/sec

Ubuntu has been installed in VMWare using easy install (or something sounding like this). Therefore the OS starts now in text mode and to access GUI I have to type startx.

How to enable the GUI with graphical login screen?

/etc/default/grub file has following values inside:

....
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
....
#GRUB_TERMINAL=console

so it corresponds to recommendations how to turn graphical login on.

I have installed JRE 1.7.0_04-b22. I disabled the "update" setting in administrator - update requests disappeared, but in ordinary user's account it is nagging me about updates and I can't turn it off. The "update" tab is grayed out. When I run javacpl.exe with administrator rights, it changes the global setting:

HKLM\SOFTWARE\Wow6432Node\JavaSoft\Java Update\Policy\NotifyDownload
HKLM\SOFTWARE\Wow6432Node\JavaSoft\Java Update\Policy\NotifyInstall

but then can't use it in ordinary user account.

To set up Passenger some packages must be installed, for example libcurl4-openssl-dev:

user@ubuntu:~$ sudo apt-get install libcurl4-openssl-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 libcurl4-openssl-dev : Depends: libcurl3 (= 7.21.3-1ubuntu1) but 7.21.3-1ubuntu1.5 is to be installed
                    Depends: libkrb5-dev but it is not going to be installed or
                             hurd but it is not installable
E: Broken packages

What to do? If I try to install them manually, they reveal their own unmet dependencies etc, etc.

sudo apt-get update

didn't help.

Adding maverick-security repository by adding

deb http://security.ubuntu.com/ubuntu maverick-security main universe restricted multiverse

in Synaptic Package Manager and then sudo apt-get update didn't help too.