[Asterisk-Users] Re: cannot call Grandstream

[Stephen R. Besch]

Neil Cherry wrote:

> 
> I never could get my time server to work with the GS.

The following is an excerpt from my web page. I also use phones on a 
private subnet. Linux is RedHat. This works for me:

The time service must be configured to allow the phones to request the 
time from your server, which must have at least one IP on the same 
private subnet as your phones, and can therefore can be reached without 
the need of a router (which won't pass any private subnet packets) and 
at least one IP on a public subnet so that it can reach a public time 
server. I run the time service on my Asterisk server. (You could set 
Asterisk up to be a master time server, but unless you absolutely must, 
I would not do this.)

First, using the Date/Time setting panel in RedHat, specify a public 
time server either by name or IP.

Once you have a valid time server defined, activate the NTP service on 
your server. You must activate the service first, since the RedHat 
applet removes any customizations that are added to the ntp.conf file 
when you activate the service from the Date/Time applet. (Is this stupid 
or what?)  Once the service is running, add the following line to 
/etc/ntp.conf :

     restrict 192.168.xx.0 mask 255.255.255.0 notrust nomodify notrap

Where xx is the common subnet of your phones and your server. Then, 
restart the time service from the services applet - NOT from the 
date/time applet!  These settings configure the time service to be a 
time mirror.  In other words, it merely accepts time settings from the 
public server you defined earlier, and passes them on to anyone that 
requests them, providing that they lie in the 192.168.xx subnet.

After that, your phones should be able to retrieve the time/date from 
the server using any IP's that you have defined in the server that lie 
on your private network

Stephen R. Besch