While working at an ISP for two years, I often needed to give technicians a script with a standard config and instructions to change variables. I started with simple text files, then custom php scripts and finally worked with a friend to create 4peg.com.


‘Screen’ is an application built into Linux and Unix based platforms that allows you to manage multiple windows within a single ssh session. However, it can also be used as a terminal for a USB to serial adapter.


Many people use sites like http://www.whatismyip.com or http://www.ipchicken.com to identify the public IP address of an unfamiliar network.

Telnet to ip.blindhog.net or if you do not have a web browser (router, switch, linux).
Note: the original domain name was v4address.com but it has not worked for a while.

[josh@webserver ~]$ telnet ip.blindhog.net
Connected to ip.blindhog.net.
Escape character is ‘^]’.
This is the telnet autoresponder at v6address.com.
You have connected over IPv4.
Your IP address is
Connection closed by foreign host.

As most of you may or may not know, Cisco currently only provides non-bootable Unified Communications ISO images on CCO for download. These ISOs are listed as being provided for “upgrades” and hence will not boot.
The only difference between these non-bootable images and a bootable disc is that the bootable disc includes a boot sector file.   Fortunately, this boot sector file can easily be extracted from a bootable disc and then injected into your non-bootable ISO.  To accomplish this, you will need to use some sort of ISO image software such as UltraISO, MagicISO, PowerISO, etc.  I prefer to use UltraISO for its ease of use.

Cisco IP Communicator (CIPC) requires a sound card be installed on a PC in order to install or open. Under normal circumstances, this completely makes sense. However, in other circumstances (demos/labs), PCs are actually virtual machines … and do not have sound cards. In these situations, the engineers/trainers/etc are more concerned with dialing than actually hearing audio.


In order to use CIPC in a virtual machine, install Virtual Audio Streaming – a virtual sound card tool from ShiningMorning.com prior to installing CIPC. This software will install virtual audio drivers on your VM which allow CIPC to install and have dialing capabilities. Unfortunately, CIPC will still only allow one instance to run at a time…unlike IP Blue. I have tested this with VMWare ESXi but it may also work with other VMWare products.

This tutorial will show you how to create or convert an existing audio file and save it in CCITT u-law – 8KHz 8bit Mono format for use in Cisco Unified Call Manager Express (CUCME), Cisco Unified Contact Center (UCCX) or Cisco Unity Express (CUE). This has always been an easy task with the Windows Sound Recorder that came with Windows XP. However, the sound recorder that comes with Windows 7 does not work the same.

This tutorial will show you how to make config changes with a simple tcl script and invoke the script from an IOS menu. I was recently presented with a scenario where the FXO ports on a customer router were not receiving the supervisory disconnect from the PBX.
Until I find a way to auto reset the ports with EEM and the long call duration flag, the temporary solution is to create a menu where the customer can view call durations and reset voice-ports with a menu. The tcl script performs a ‘shut’ and ‘no shut’ on the voice port.

Bit-Twist is a simple yet powerful libpcap-based Ethernet packet generator. It is designed to compliment tcpdump or wireshark packet captures. In this tutorial, you will learn how to edit and replay network packet captures files on a live lab network.

This tutorial is a continuation of the virtual voice lab series. In this tutorial, you will add a dial-plan to the PSTN router that was added in the first part of the PSTN simulation lab. (more…)

Occasionally, I have run into the issue when turning up a PRI that ring back is not heard when placing an inbound call. Caller only hears silence until the called party answers. This seems to be more prevalent with smaller Telco’s who don’t have a lot of experience with PRIs.


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