Asterisk Pakistan

Before your upgrade your telephony structure to VoIP, I recommend that you understand how the telephony works and how VoIP will play and important part supporting your ever growing business requirements.

Please download the Understanding Telephony show or PDF of Understanding Telephony.
Understanding Telephony (PDF) 762KB
Understanding Telephony (PowerPoint) 2.8MB

Digium has created wide rang of analog and digital telephony cards. These cards come in different port ranges as per your requirement.

Digium Analog Cards
All analog cards are modular in nature on which you can add or remove daughter boards as per your requirement. There are four basic components in a card

1) Base Card
2) Daughter Boards (FXO / FXS)
3) Echo Canceller
4) External Interface (24 port only)

Analog Base Cards
Analog base cards from Digium come in 4, 8, and 24 port range. FXO (red) and FXS (green) are daughter board cards that can be installed on the base card to achieve connectivity with either telephony company or creating an analog extension. Digium analog base cards are available in both PCI and PCI Express interfaces.

These cards can be created can have custom configuration. For example on a 4 port card, you can add two FXO cards and two FXS cards to create two incoming line and two analog extension PBX

FXO and FXS Cards
FXO and FXS daughter cards give Digium analog phone cards functionality of receiving calls or creating extensions.

FXO stands for Foreign eXchange Origination, means where you will plug the lines coming from your telephone company (Trunk lines).

FXS stands for Foreign eXchange Station, means an analog extension that you will create in your home/office.

FXO and FXS daughter boards are available in single port and Quad port configurations. Single port cards provide single line functionality and can be used on 4 and 8 port analog cards, where are quad port cards provide 4 line functionality and can be used on 8 and 24 port analog cards.

Digium has also provided a very good illustration on their website about FXO and FXS. You can view it using the following link http://www.digium.com/en/docs/misc/fxs_fxo_desc.php

Echo Canceller
For Asterisk users who connect to the PSTN (Public Switched Telephone Network), the most common type of echo is hybrid echo - the echo introduced by the impedance mismatch between 2-wire and 4-wire telephone circuits. The echo manifests as a distorted and delayed reflection of the users voice while in conversation with an external party through the PSTN.

The hardware based echo canceller will provide 128ms (1024 taps) of echo cancellation across all of its channels.

External Interface
Only 24 port card requires external interface. Since the cards back plate does not have enough space for 24 ports so a special 50-pin interface is provided. You must 50-pin connector cable and 24 port connector box in order to connect to your trunks or extensions.

Please note that card price does not include cable and patch panel. All of these are sold separately.
Digium Analog Card Model Numbers
Digium naming convention is very easy to understand.

Analog Cards Naming scheme
Typical naming scheme looks like III X S O E/B

Where III is the Interface type and can be AEX for PCI Express and TDM for PCI

X is the number of Port and can be 4, 8, 24

S is the number of extensions or FXS lines

O is the number of trunk lines

E/B can be either E which means hardware echo cancellation module included or B which means only base card.

PCI (3.3V or 5V) cards start with TDM and PCI express cards start with AEX. PCI is the most common interface to be found on mother boards. All new server boards now offer PCI Express which is faster than PCI. Please see the figure below to identify PCI and PCI Express interfaces

 
TDM 808E means PCI 8 port card with 0 extensions and 8 trunk lines and hardware echo canceller.

A call center is a centralized office used for the purpose of receiving and transmitting a large volume of requests by telephone. A call centre is operated by a company to administer incoming product support or information inquiries from consumers. Outgoing calls for telemarketing, clientele, and debt collection are also made. In addition to a call centre, collective handling of letters, faxes, and e-mails at one location is known as a contact centre.

A call centre is often operated through an extensive open workspace for call centre agents, with work stations that include a computer for each agent, a telephone set/headset connected to a telecom switch, and one or more supervisor stations. It can be independently operated or networked with additional centres, often linked to a corporate computer network, including mainframes, microcomputers and LANs. Increasingly, the voice and data pathways into the centre are linked through a set of new technologies called computer telephony integration (CTI).

This guide will help you setup your first asterisk server. You don’t need to even know linux to make Asterisk work. Just follow the simple steps below to install asterisk

Requirements

• Spare/extra computer (Pentium III 1GHz or higher)
• CD Writer
• Spare/Extra hard drive (20GB or higher)
• LAN Card (to connect to Internet / LAN)
• VoIP Phones (Standard telephone set, IP Phones, ATA or Softphones)
• Headphones incase if you are using softphones
• Phone lines from PTCL (Pakistan telecommunication Company Limited)
• Digium TDM 400 / 800 / 2400 card (Optional and as per your requirement)
• Blank CD

Downloading AsteriskNOW

The first thing you need to do is to download the ISO image of AsteriskNOW. To download, please follow this link http://www.digium.com/elqNow/elqRedir.htm?ref=http://www.asterisknow.org/files/downloads/load_balance.php?q=AsteriskNOW-1.0.2.1-x86-disc1.iso

Make sure that you download the file completly. Use GetRight or any other web downloading software which supports download resuming.

Writing the ISO Image file
Since the AsteriskNOW image is an ISO, you cannot simply copy this file on the CDROM. In order for this CD to be bootable, you have to write the image properly. Use imgburn to write the downloaded file.

Preparing the System
AsteriskNOW CD will destroy all the data on your hard drive. Please make sure that you install a spare hard drive on your system and keep the existing one safe. It is recommended that you buy a spare used PC from the market to play around with Asterisk. Make sure that you enable BOOT FROM CDROM option from your computer’s BIOS.

Installing AsteriskNOW
Once your computer is ready, place the CD in the CDROM and reboot your computer. You should see the following screen when your computer boots up

Just press ENTER button on the keybaord to continue. Altough the GUI installation is compatible with most graphic cards, it might give you tough time with some graphic cards and there will be no display at all. If you experience this, reboot the PC. When this option is promoted again, type linux text and press  ENTER key.

The setup will guide you through various steps. Make sure that you write down all the settings on a writing pad before continuing with each step. Most of the users forget the settings that had to go with a reinstallation wasting lot of time.

Make sure that your network settings are correct when prompted. Do not use DHCP address. Use a static IP address so that you can connect to it later on with your web broswer. If you are using a DSL modem and a wireless router as your swtich, typical IP addresses are 192.168.0.1 for wireless router. Setup 192.168.2.10 as network IP of AsteriskNOW server or set it to what ever you like with-in the same network segment.

 After Installation
Once your installation is complete, you will be prompted to reboot your computer. Once rebooted, you will see asterisk prompt. Your work on this computer is almost finished. You can now play with asterisk from another computer using web browser. If you have Windows XP with IE 6.0, the GUI will not work. Use firefox 2.0 or above to view the AsteriskGUI

To login to asterisk GUI type http://192.168.0.10 or what ever is the IP address of your asterisk server. You should see a setup wizard page, just like the image below

The wizard will pick and configure all Digium Analog cards automatically. You can purchase analog cards from www.brismark.com. Digium cards are now locally available in Pakistan at very same prices.
If you are new to Digium Analog/Digital Telephony cards, I suggest you should read this article before you proceed with the Wizard.

AsteriskNOW® is an open source Software Appliance; a customized Linux distribution that includes Asterisk (the leading open source telephony engine and tool kit), the AsteriskGUI™, and all other software needed for an Asterisk system. AsteriskNOW is easy to install, and offers flexibility, functionality and features not available in advanced, high-cost proprietary business systems.

AsteriskNOW® is your fastest way to setup IP PBX at your home/office, setup a small call center or IVR.

Introduction

VOIP is an acronym for Voice Over Internet Protocol, or in more common terms phone service over the Internet.
If you have a reasonable quality Internet connection you can get phone service delivered through your Internet connection instead of from your local phone company.

Some people use VOIP in addition to their traditional phone service, since VOIP service providers usually offer lower rates than traditional phone companies, but sometimes doesn’t offer 911 service, phone directory listings, 411 service, or other common phone services. While many VoIP providers offer these services, consistent industry-wide means of offering these are still developing.

Applications using VOIP

Traditional telephony applications, such as outbound call center applications and inbound IVR applications, normally can be run on VOIP.

Why use VOIP?

There are two major reasons to use VOIP

• Lower Cost
• Increased functionality

Lower Cost

In general phone service via VOIP costs less than equivalent service from traditional sources. This is largely a function of traditional phone services either being monopolies or government entities. There are also some cost savings due to using a single network to carry voice and data. This is especially true when users have existing under-utilized network capacity that they can use for VOIP without any additional costs.

In the most extreme case, users see VOIP phone calls (even international) as FREE. While there is a cost for their Internet service, using VOIP over this service may not involve any extra charges, so the users view the calls as free. There are a number of services that have sprung up to facilitate this type of “free” VOIP call. Examples are: Free World Dialup and Skype

Increased Functionality

VOIP makes easy some things that are difficult to impossible with traditional phone networks.

• Incoming phone calls are automatically routed to your VOIP phone where ever you plug it into the network. Take your VOIP phone with you on a trip, and anywhere you connect it to the Internet, you can receive your incoming calls.
• Call center agents using VOIP phones can easily work from anywhere with a good Internet connection.

This document is intended for audience

Asterisk is the world’s leading open source telephony engine and tool kit. Offering flexibility unheard of in the world of proprietary communications, Asterisk empowers developers and integrators to create advanced communication solutions…for free.

Asterisk® is released as open source under the GNU General Public License (GPL), and it is available for download free of charge. Asterisk® is the most popular open source software available, with the Asterisk Community being the top influencer in VoIP.

To learn more about asterisk, visit http://www.asterisk.org/support/about