System information
Quite a few of the chapters in this book contain information that will help you inter-
nationalize
*
or (perhaps more properly) localize your Asterisk implementation. The
purpose of this chapter is to provide a single place where all aspects of the changes that
need to be made to your Asterisk-based telephone system in this context can be refer-
enced, discussed, and explained. The reason for using the phrase “Asterisk-based tel-
ephone system” rather than just “Asterisk” is that some of the changes will need to be
made in other parts of the system (IP phones, ATAs, etc.), while other changes will be
implemented within Asterisk and DAHDI configuration files.
Let’s start by getting a list together (in no particular order) of the things that may need
to be changed in order to optimise your Asterisk-based telephone system for a given
location outside of North America. You can shout some out if you like…
• Language/accent of the prompts
• Physical connectorization for PSTN interfaces (FXO, BRI, PRI)
• Tones heard by users of IP phones and/or ATAs
• Caller ID format sent and/or received by analog interfaces
• Tones for analog interfaces to be supplied or detected by Asterisk
• Format of time/date stamps for voicemail
• The way the above time/date stamps are announced by Asterisk
• Patterns within the dialplan (of IP phones, ATAs, and Asterisk itself if you are using
the sample dialplan)
• The way to indicate to an analog device that voicemail is waiting (MWI)
• Tones supplied to callers by Asterisk (these come into play once a user is “inside”
the system; e.g., the tones heard during a call transfer)
We’ll cover everything in this list, adopting a strategy of working from the outer edge
of the system toward the very core (Asterisk itself). We will conclude with a handy
checklist of what you may need to change and where to change it.
Although the principles discussed in this chapter will allow you to adapt your Asterisk
specifically for your region (or that of your customer), for the sake of consistency all of
our examples will focus on how to adapt Asterisk for one region: the United Kingdom.
Devices External to the Asterisk Server
There are massive differences between a good old fashioned analog telephone and any
one of the large number of IP phones out there, and we need to pick up on one of the
* i18n is a term used to abbreviate the word internationalization, due to its length. The format is
<first_letter><number><last_letter>, where <number> is the number of letters between the first and last
letters. Other words, such as localization (L10n), modularization (m12n), etc. have also found a home with
this scheme, which Leif finds a little bit ridiculous. More information can be found here: http://www.w3.org/
2001/12/Glossary#I18N.
182 | Chapter 9: Internationalization