Fax & Voip – Part 3/3 – Baud Rate & Fax Relay

oldfaxmachineDecrease Baud Rate and turning off ECM
Packet loss, jitter, and latency all add up to corrupt a fax transmission in VoIP env
and unfortunately also in Asterisk PBX.

When a fax machine determines that some data is lost, it will shut down the entire fax transmission, even though you would still have a workable document.

By slowing down the transmission speed up to 9600 bps, you’ll increase the probability that all the faxes will be transmitted or received correctly.

To slowing down the BAUD rate to 9600 bps you need to check the parameteres of the fax device. Continue reading

How to compact VirtualBox’s VDI file size

bimboingabbiaIf in creating process of Virtual Box VM you have selected the option Dynamically Expanding Storage, you will find that the file size expands whenever you install new applications in the VM or add new files.
However, when you uninstall or delete applications, the file size of the VM does not shrink: if you are constantly installing and uninstalling applications in your VM, the VDI file could be taking up more space than it is actually using.
In this post I?ll show the steps to shrink your Virtualbox VM. Continue reading

Acer Revo M1-601: How to install Asterisk & Freepbx

acer-m1-601To begin you need to install Debian 8.1.

Critical step in the installation process.
Non-free firmware
When the installation process ask for “Some of you hardware needs non-free firmware¬† – the missing firmware files are rtl_nic/rtl8168g-2.fw”, you need to download from Debian Packaged web site package named firmware-realtek (see linkografia), uncompress it to an USB stick (using 7zip for example): after that you can insert USB key in your Acer and continue with installation process.

Disk Partition
My choice: Guided – use entire – all file in one partition

Software Selection
My choice: SSH server and standard system utilities

Root SSH Access
You need to permit root user to get via SSH in order to facilitate the configuration steps.

> sed -i 's/PermitRootLogin without-password/PermitRootLogin yes/' /etc/ssh/sshd_config
> service sshd restart

Continue reading