Home VoIP over WiFi experience
My considerations for deployment were all around avoiding the wiring hassle of connecting my phone extensions on three floors to the NBX on one of them. Specifically, I purchased three power strips and plugged in the power brick of the 3Com 3102 phone and the Apple Airport Extreme. The Ethernet cable that came with the 3102 phone was plugged into the phone and the Airport Extreme. I configured each phone and each Airport Extreme through a process of trial and error. Since every configuration change of either required a reboot, it took a while to get it right (several days as I recall).
This is also how I learned that there is a limit of four Extremes per base station.
I used black electrical tape to link the power and Ethernet cables going to the phone. Most enterprises use Power over Ethernet and avoid the whole power brick thing, but since you can't find a Power over Wireless (other than RFID) solution, I was stuck.
In addition to the four WiFi-based extensions, I have two other extensions. One used the independent switch port in the back of the IP phone to connect to a second phone.
The other extension links in the 3Com 3106c (900 MHz cordless) through that spare Ethernet switch port on the back of another 3Com 3102.
The 3Com 3102 phone is all black plastic with a B&W 3-line LED display. The plastic stand to prop the display up in a way for desktop users, is not effective. I find that with only the slightest of pressures, it often collapses, preventing me from seeing the display effectively as a call comes in, and requiring both hands to reassemble the phone. Most annoying.
Voice call quality is generally poor, losing much of the upper and lower frequencies but as my family will testify, is probably due to my hearing loss.
The speaker phone is functional, but not of particularly high quality. The sound level control does not amplify the audio enough, and is directionally challenged. The speaker must be stationary and speak directly into the phone.
Some of these audio quality issues may be related to the lossy WiFi interface, yet in my experimentations, it seems to be consistent with 100 Mb Ethernet usage.