System Administration, Telephony

GXP2020EXT Provision & Template

The Grandstream GXP2020EXT is an accessory “sidecar” (or in Grandstream-speak “Expansion Module”) that adds 56 speed dials with BLF to Grandstream model GXP20xx VoIP telephones. In the article below I’ve provided two scripts to help GXP2020EXT users keep their units programed with fresh directory information and matching card inserts. The Problem As the phone system…
Hacks, Telephony

Phone Phreak Silver Box

How many Touch-Tone digits does your landline have? 12 ? …That’s so pedestrian. If you’re a phone geek you might know about the old military AUTOVON phone system. These phones added 4 additional digits, that could be used to indicate the urgency of the call. P for priority, I for immediate, and F for flash…
Bash, System Administration, VBScript

Finding Malware URLs in W97M infected Word Docs

An email with a trojan Microsoft Word document made it past the spam filter today at work. At least one user reported opening the attachment. The attachment was named: DOCO943488.doc, but running the file through virustotal.com it was clear that it’s been known by other names.. To help affected people find this page here are…
System Administration

Glimpsing the Heap

You connect into the server and type “w” to see who else is on. You see a connection from an IP you don’t recognize! [cc theme=”blackboard” width=”100%” height=”100%”] 14:43:11 up 5 days, 22:32, 2 users, load average: 0.52, 0.41, 0.36 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT root pts/0 203.0.113.17 Wed10 2days 0.31s 0.31s…
Bash

Bash Snippet: Luhn Algorithm

I like Bash, but it isn’t well suited for some tasks. For fun I sometimes ignore that. Occasionally people seem to find this useful. In that spirit, here is my implementation of the popular Luhn / mod10 algorithm used in credit card, IMEI, and other number sequences. download [luhn.zip] [cc theme=”blackboard” width=”100%” height=”100%” lang=”bash”] #…
Arduino, Hardware

Retro-Joystick to USB Keyboard Adapter

Project Introduction I made an adapter to take classic video game controllers for Sega, Atari (2600, 7800) and Commodore (VIC20, C64, C128) and adapt them to work as a 5 button USB keyboard (4 directions and a fire/trigger key). The joystick now works like an external numeric keypad. Pressing the fire/trigger button will act like…
Arduino, Hardware

Arduino Leonardo (ATMega32u4) USB Power Button

Project Introduction For fun I made this USB power button with an Arduino Micro/Leonardo-like board (by which I mean one using the Atmel ATMega32u4 MCU with USB controller). The project details are below in case you should want to read or watch how I did it. I used an ATMega32U “arduino”-like board from Amazon.com although…
Hardware, Raspberry Pi

Raspberry Pi RTS / CTS Flow Control

I had need of a 3.3v TTL serial interface to reprogram a device I was working on. Looking around I realized I had mostly 5v logic USB to serial adapters. I figured the Raspberry Pi would work well enough, but I also needed hardware flow control. As it turned out the Pi can do RTS…
Telephony

Elastix *69 (Call Trace) Fix

We’re running an older installation of Elastix at my office, version 2.0.0 (release 58) on top of freePBX version 2.7.0 (release 10). The call trace feature was bothering me. This feature is mapped to the *69 feature code as is common with many LECs in North America. In the default implementation you hear an announcement…
Telephony

Install Certified Asterisk 13 from source on Ubuntu 14.04 LTS

Need an Asterisk setup? Why not combine the long term support of an Ubuntu LTS release with the long term support of a Certified Asterisk release? Certified Asterisk releases are supported for around 4 years, and Ubuntu LTS for around 5 years, helping ensure you don’t need to mess around with major reconfiguration again for…