The phone’s configuration files are loaded from a TFTP server at power-on. If DHCP is enabled on the handset the DHCP service option 66 must provide the IP address of the TFTP server. This is consistent with Polycom’s established provisioning process for the SoundPoint SIP desk phones. If DHCP is disabled, then all the network parameters, including the IP of the TFTP server, must be manually entered into the handset.
Once the TFTP server is contacted, the phone prompts for a username and password. Based on the username entered, the phone then downloads the associated configuration files. The configuration files are not stored locally on the phone. This is handy, as it allows the phone to be passed from user-to-user, assuming that individuals login when they switch phones so that the handset has the user's proper extension number.
The core configuration is a two-part system with a file that is common to all handsets on the system (sip_allusers.cfg) and a user-specific file (ex. sip_1505.cfg).
The major benefit of this provisioning scheme is scalability and easy administration. With central provisioning it’s a simple matter to add or remove users, or push a new firmware release to an entire fleet of handsets.
The documentation provided with the phone gives comprehensive, notated examples of the config files. In my case the settings were very simple.
CODECS = g711u, g711a
PROXY1_ADDR = 192.168.1.200:5060
PROXY1_MAIL_ACCESS = 7999
PROXY1_KEYPRESS_2833 = disable
PROXY1_KEYPRESS_INFO = enable
PROXY1_HOLD_IP0 = disable
AUTH = 1505; 1505
LINE1 = 1505
LINE1_PROXY = 1
LINE1_CALLID = Sip Phone 1505
The phone supports up to five “lines” where each line is a separate SIP registration. A SIP registration may also be entered multiple times allowing for multiple simultaneous call appearances on that line. Each user profile can also contain a list of “favorites” that are effectively speed-dials for that user.
Two of the fundamental problems facing most Wi-Fi SIP handsets are cordless range and battery life. Simply put, Wi-Fi was not designed with conservation of power consumption as a top priority. So Wi-Fi radios tend to draw considerable power continuously, which can result in lackluster battery life. Ramping down transmit power isn't a viable power conservation optione, either, since it limits range.
Happily, in the SpectraLink 8002, Polycom has elected to use a substantial NiMH battery. Polycom wouldn't tell us the battery mAh capacity and there is no marking on the battery pack. But the specified talk time is up to 3 hours, with up to 50 hours of standby operation. I was happy to find that these claims were met over the period of my evaluation. I used the phone over a period of a few weeks without ever feeling that the battery life was a problem.
For heavy users, Polycom offers a charging stand that will charge both the handset and a spare battery, making it more convenient to always have a charged spare battery at the ready. I suspect that serious commercial users will find this option a necessity.
For pure data applications, a WLAN may be designed with spot coverage to provide a data connection to a bank of cash registers, for example. But if you intend to deploy Voice-over-Wi-Fi (VoWifi), then you'll need good signal coverage over an entire facility.
To help in spotting RF coverage dead zones, the 8002 provides a handy site survey mode (Figure 5). This function provides a real-time readout of the RF signal level of your WLAN as you wander about your facility. When engaged in this mode, the LCD displays the ESSID, RF level, RF channel, WLAN type and security type. You can easily use this tool to map out any holes in your access point layout.
Figure 5: Display with phone in site survey mode
During the few weeks that I used the SpectraLink 8002, it generally served me well. WMM worked as promised; calls were never choppy because of data activity on the WLAN.
Voice quality was in general very good. I was also pleased to find that the handset provides a generous range of volume, which helps me when I’m working near loud server racks.
It takes a little time to get used to using the four function buttons just below the LCD. At first they appear to be two large elliptical buttons, but are, in fact, four separate buttons. Common calling functions like mute, hold, redial and transfer are easily accessed via these buttons.
The Polycom 8002 supports both alpha and numeric dialing. It’s much simpler to dial by number from the phone itself, but one can enter a SIP URI directly if required. I found it easier to use SIP URIs in the “favorites” loaded from the provisioning server rather than entering them on the handset manually.
My home and office comprise an area of around 18,000 square feet. With one access point located in my home office, I found that I could reliably use the handset in about 70% of the property. If I were to relocate the access point to a more central position on the property or add a second access point I’m confident that I could use the phone across the entire property.
With the single access point, the useful range of the phone was just a little less than what I’m accustomed to using DECT cordless phones, but considerably more than any previous Wi-Fi handset I have used. I expect that this is as much a result of the newer wireless router as the phone itself.
I must admit that I was prepared to be disappointed with this little phone. My earlier experience with Wi-Fi SIP phones was not good. But the Polycom name gave me reason to expect more from the 8002 and it delivered. The combination of a recent-generation access point and the 8002 proved very capable.
However, this is a system better suited for small businesses and is less suited to SOHO users such as myself. For home use, there is little to be gained by converged VoWifi. DECT solutions, while less scalable, are readily available, inexpensive and easily deployed beside Wi-Fi networks.
However, for businesses that are already on a path to voice/network convergence, the Polycom 8002 is a viable option for implementing VoWifi as an aspect of their telecom strategy.