System information

usually dial the IP address of the other phone just by using the * key for the dots in
the address.
Figure 9-2 points to the fact that on an IP phone, we are responsible for setting all of
the tones that the network would have provided in the old days. This can be done in
one of (at least) two ways. The first is to configure the tones provided by the IP phone
on the device’s own web GUI. This is done by browsing to the IP address of the phone
(the IP address can usually be obtained by a menu option on the phone) and then
selecting the appropriate options. For example, on a Yealink IP phone, the tones are
set on the Phone page of the web GUI, under the Tones tab (where you’ll find a list of
the different types of tone that can be changed—in the case of the Yealink, these are
Dial, Ring Back, Busy, Congestion, Call Waiting, Dial Recall, Record, Info, Stutter,
Message, and Auto Answer).
The other way that this configuration can be applied is to auto-provision the phone
with these settings. A full explanation of the mechanism for auto-provisioning is beyond
the scope of this book, but you can usually set up the tones in the appropriate attributes
of the relevant elements in the XML file.
While we are changing settings on the IP phones, there are two other things that may
need to be changed in order for the phones to look right and to function correctly as
part of the system.
Most phones display the time when idle and, since many people find it particularly
annoying when their phones show the wrong time, we need to ensure that the correct
local time is displayed. It should be fairly easy to find the appropriate page of the web
GUI (or XML attributes) to specify the time server. You will also find that there are
settings for daylight saving time and other relevant stuff nearby.
The last thing to change is a potential show-stopper as far as the making of a phone
call is concerned—the dialplan. We’re not talking about the dialplan we find in /etc/
asterisk/extensions.conf, but the dialplan of the phone. Not everyone realizes that IP
phones have dialplans too—although these dialplans are more concerned with which
dial strings are permitted than with what to do on a given dial.
The general rule seems to be that if you dial on-hook the built-in dialplan is bypassed,
but if you pick up the handset the dialplan comes into play, and it just might happen
that the dialplan will not allow the dial string you need to be dialed. Although this
problem can manifest itself with a refusal by the phone to pass certain types of numbers
through to Asterisk, it can also affect any feature codes you plan to use. This can easily
be remedied by Googling the model number of the phone along with “UK dialplan”
(or the particular region you need), or you can go to the appropriate page on the web
GUI and either manually adjust the dialplan or pick the country you need from a drop-
down box (depending on the type of phone you are working with).
184 | Chapter 9: Internationalization