38Planning
Figure 2
Sample DHCP reservation showing assigned parameters
Another use for the DHCP server is to make code upgrades to the handset easier. To prevent handsets from checking for code upgrades, assign the value of 255.255.255.255 for the TFTP server address.
A problem can arise for handset users who travel. For example, the company employing the handset solution is a retailer with many stores. Each store has a local call server for the local employees who use various VoIP devices, so all the attributes are defined at the scope level. What happens if supervisors, who travel from store to store, want to use their handsets at each location? The supervisors can be assigned to a signaling server that does not recognize their phones. The best way to support these users is to create unique reservations in each remote scope for each user’s WLAN handset and specify the proper signaling server. This solution can be cumbersome if there are a large number of users who travel.
TFTP Server planning
A TFTP Server (RFC1350) holds the software images for updating the handsets and the WLAN IP Telephony Manager 2245. After the IP address of the TFTP server is configured on a wireless handset, each time the wireless handset is powered on, the wireless handset checks its version of firmware against the firmware on the TFTP Server, and if the version is different, the wireless handset downloads the new firmware from the TFTP Server. Similarly, when a WLAN IP Telephony Manager 2245 reboots, or is manually reset by the operator, it checks its version of software against the version on the TFTP Server. If the versions are different, the WLAN IP Telephony Manager 2245 downloads the new software.
The WLAN Handsets 2210/2211/2212 and WLAN Handsets 6120/6140 share the same configuration file that provides firmware version information for the TFTP process. The actual software files are specific to either the WLAN Handset 2200 series or the WLAN Handset 6100 series. At an installation, which uses both the WLAN Handsets 2210/2211/2212 and the WLAN Handsets 6120/6140, the software files for both handset series must be installed and available on the TFTP server for the site.
Nortel Communication Server 1000
WLAN IP Telephony Installation and Commissioning
Release 5.0 15 June 2007
