s Creating CNF files Next, we're going to put some limits in our system. I'm going to limit the number of phones to 16 and the number of dial numbers to 128: R1-PBX(config-telephony)#max-ephones 16 R1-PBX(config-telephony)#max-dn 128 Why limit the number of phones? If you have a very static environment, limiting the number of phones will prevent rogue phones from registering. Believe it or not, this can be a real problem. If you try to lower this number later, you will be treated to this message: R1-PBX(config-telephony)#max -ephones 8 Please remove ephone 9 to 16 by re-configuring or reloading the system! ! Setting themax-dn value can help you rein in your dial plan. Both settings default to zero. Small-Office VolP Example Next, we'll configure the phone system SO that it uses the IP address of the voice VLAN on this router (int f0/0.902): R1-PBX(config-telephony)# ip source-address 192.168.2.1 port 2000 CNF files updating complete Since this information is critical to the phones' operation, the config files are automat- ically updated, again because of the create cnf-files command entered earlier. Now we'll configure the system message. This message will appear on every registered phone. Generally, this is the company name, but it can be anything that you or the client want it to be: R1-PBX(config-telephony)#system message GAD Technology We need to set the time zone for the phone system. The phone system defaults to universal time as learned from the router, so, regardless of the router's time zone setting, you will need to configure the time zone here. You must choose the number of the time zone from the included list: R1-PBX(config-telephony)#time-zor ? <1-53> select timezone name used by IP phones (offset in minutes) 1 Dateline Standard Time -720 2 Samoa Standard Time -660 3 Hawaiian Standard Time -600 4 Alaskan Standard/Daylight Time -540 5 Pacific Standard/Daylight Time -480 6 Mountain Standard/Daylight Time -420 7 US Mountain Standard Time -420 8 Central Standard/Daylight Time -360 9 Mexico Standard/Dayli