So I was answering a friend who had inquired about how the boot up process works on a ShoreTel phone when I thought....hummmm...this would make a great blog entry because I'll forget iit n a few months. :)
So assuming we have the network configured as I have shown in the last blog entry (VOIP vlan 19, user vlan 14), we plug a brand spanking new phone into the switch on port A1. Assuming you have your DHCP server set up correctly (which we will cover in just a minute) the phone will be into the untagged vlan 14 and request a DHCP address. It gets one, but it also get the DHCP Option 156. This option is used by the ShoreTel phone to determine where it's vmail server is as well as where it should live in the network. It see's that it should live in vlan 19 and reboots. Now it uses tagged info on vlan 19 to request a new DHCP address. This time it gets one in the 10.3.9.x range and goes about its business. One thing I fail to mention here is the first time this happens it's reboot city for the phone. New phones, even out of the box seem to need an upgrade when the connect to the ShoreTel server. On my gig network this first boot and config of the phone takes like 10 minutes.
Ok, on the DHCP server we have to set up option 156. First right click on the DHCP server in the DHCP Server Manager tool and select "Set pre-defined options". Here you need to add option 156 so it appears as an option at the vlan scope level. Set the data type to string. Once the item is created go to vlan 14 (which the phone first boots looking for the info) and add scope option 156. The string format should be something like:
ftpservers=10.3.19.99, country=1, language=1, layer2tagging=1, vlandid=19
10.3.19.99 is the address of the ShoreTel server, country is set to USA, language is set to english, layer2tagging is set to 1 or yes and vlanid is the vlan id of the vlan for voip.