|
Displays network configuration and uses profiles Bad
Lack of call history, redial and voicemail indicator features
Connector is available for only the 3Com NBX 100
Long wait during initialization |
We installed the 500-KB-footprint SymPhone Client on a 3800 series Compaq iPaq, a Toshiba E740, an Intermec 700 and an HP Jornada. Although all the more popular clients are available for download on TeleSym's Web site, we had to specifically request a build for the Intermec device--a specialized Pocket PC handheld computer with integrated WiFi wireless and a small keyboard. What sets the Intermec device apart for this application is its combination headphone/microphone jack, which lets you use traditional cell phone headsets. In contrast, while you can listen through the headphones for standard Pocket PC devices, you need to speak into the integrated microphone.
The Tests and The Results
To see the SymPhone in action, we simulated VoIP traffic on our WLAN using NetIQ's Chariot 4.3 with the latest VoIP endpoints using the G.711u codec. With 30 simultaneous calls (64 Kbps each direction) on the network, we initiated a call with the SymPhone and experienced a round-trip delay of approximately 185 milliseconds. Under congestion, the average lost data between the endpoints was 70 percent. Dropping the number of calls to 20, we observed that the SymPhone's integrated call-quality meter changed from "poor" to "good." With 10 calls, round-trip latency averaged 70 milliseconds and average data loss between the endpoints was less than one percent. With no additional VoIP traffic, the meter returned to normal. Even under significant congestion, SymPhone's voice quality was good. It's important to note, however, that normal sound for the SymPhone is nothing short of spectacular; it approaches CD quality. TeleSym obviously has spent a lot of time and effort tuning the codec for high quality.
We also tested the effects of call quality while moving in and out of access point range. Calls were interrupted when moving out of range, but reconnected when we came back into range. Although the SymPhone indicated that it was trying to re-establish the call, there was no indication to the party who stayed within range that we had moved out of range and were trying to re-establish the call. The average time before the call was actually dropped was around 55 seconds--a tad long. Happily, SymPhone calls reconnected even when the Cisco network card or Symbol compact flash card was removed and re-inserted.
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