Telephony System Integrator's Guide (Asterisk) - Citrix Knowledge ...

Citrix EasyCall Gateway
Telephony System Integrator’s Guide
for Asterisk-Based Telephony Systems
Citrix ® EasyCall Gateway 3.0

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Document Code: July 24, 2009 (KP)

CONTENTS
Contents
Chapter 1
Asterisk SIP Trunk Integration
Equipment Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Asterisk-Based Telephony System Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Integrating with Asterisk. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Integrating with trixbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Verifying the Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Call Detail Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

iv
Telephony System Integrator’s Guide

CHAPTER 1
Asterisk SIP Trunk Integration
This chapter describes how to integrate Asterisk ® -based telephony systems with the
EasyCall Gateway through a SIP trunk. The EasyCall Gateway can be integrated with
Asterisk 1.2 and 1.4 servers.
Note Asterisk is an open source/free software implementation of a telephone private
branch exchange (PBX). Like any telephony system, it allows a number of
attached telephones to make calls to one another, and to connect to other
telephone services including the public switched telephone network (PSTN).
The integration described in this chapter can be done in tandem with EasyCall
Gateway installation and configuration, which includes defining the properties of the
telephony system trunk and defining any changes the EasyCall Gateway makes to
telephone numbers before sending them to the telephony system for dialing. The
EasyCall Gateway always listens on port 5060. Be default, the EasyCall Gateway
communicates with the SIP trunk over port 5060; that port is configurable. For
information about EasyCall Gateway configuration, refer to the EasyCall Gateway
Administrator’s Guide.
Those responsible for configuring the telephone system must have the specific
characteristics for the site available before attempting to integrate the EasyCall
Gateway. Integrating the telephone system with the EasyCall Gateway is similar to
integrating the telephone system with a voicemail system.
The following topics describe a sample configuration of Asterisk-based telephony
systems:
“Equipment Requirements” on page 2
“Asterisk-Based Telephony System Integration” on page 2
“Verifying the Integration” on page 4
“Call Detail Records” on page 4

2 EasyCall Gateway Telephony System Integrator’s Guide
Equipment Requirements
Only the EasyCall Gateway appliance is required to integrate with an Asterisk-based
telephony system. The following diagram shows the integrated components.
Asterisk-based telephony system integrated with the EasyCall Gateway
As shown in the diagram, the SIP trunk makes telephone calls over an Internet
connection. The use of SIP trunks does not require modification to your existing
telephony system or Internet connections and does not require PRI hardware or
telephony system upgrades. Only outbound SIP trunks are required; the number of
trunk channels used can be scaled to your needs. For information on capacity
planning, refer to the EasyCall Gateway Administrator’s Guide.
Asterisk-Based Telephony System Integration
This section contains configuration examples for Asterisk-based telephony systems.
Use the first example as a guide if your Asterisk implementation does not have a
graphical user interface. Many organizations use telephony system products, such as
FreePBX and trixbox, which extend the telephony features of Asterisk and include a
graphical user interface. The trixbox example is provided as a guide for such systems.
“Integrating with Asterisk” on page 3
“Integrating with trixbox” on page 4

Chapter 1 Asterisk SIP Trunk Integration 3
Integrating with Asterisk
For Asterisk-based telephony systems that do not have a graphical user interface, you
must modify two configuration files and run two commands from the Asterisk
command line interface, as follows.
To integrate with Asterisk-based telephony systems
1. Modify the sip.conf file so that it contains the following:
[general]
context=default
bindport=5060
[EasyCallTrunk]
context=easycall
type=friend
host=1.2.3.4 ; IP address of EasyCall Gateway
port=5060
disallow=all
allow=ulaw
dtmfmode=rfc2833
2. Modify the extentions.conf file so that it contains the following:
[easycall]
exten => s,1,Answer()
exten => s,2,Dial(...)
3. Run the following Asterisk CLI commands:
>sip reload
>dialplan reload

4 EasyCall Gateway Telephony System Integrator’s Guide
Integrating with trixbox
If you use the trixbox user interface, use the following procedure to enable the
telephony system to accept connections from the EasyCall Gateway.
To allow the EasyCall Gateway as an incoming peer to trixbox
1. In the trixbox FreePBX interface, click the General Setting link in the left
navigation area.
2. Set Allow Anonymous Inbound SIP Calls to Yes.
The trixbox will allow requests from all SIP servers.
3. Submit the change.
That change updates extensions_additional.conf with the parameter:
ALLOW_SIP_ANON = yes.
Verifying the Integration
Call Detail Records
You are responsible for ensuring that the parameters you set will work in your
environment. While the integration information in this guide is intended as a general
guideline, each environment differs and the information in this guide might not be
accurate or complete for your site.
After completing the integration, install EasyCall on one or more user PCs and place
different types of calls (domestic, international).
A Call Detail Record (CDR) is a file that contains information about calls placed
through the EasyCall Gateway. Information provided in the CDRs can be used for
billing calls to cost centers and for auditing potential abuse.