classicsat said:
Most 900 mhz phones are analog (I am pretty sure ours is; a nearly 3 or 4 year old Uniden), so will have no effect whatsoever.
Be careful with that statement. I have 2 900Mhz DSS (Digital Spread Spectrum) cordless telephones. There are also a number of 2.4G analog phones out there. Don't confuse the frequency with transmission technology.
It should also be noted that many QUALITY digital telephones that use DSS don't use any compression at all, but spread the signal over several frequencies. If you have a lot of 2.4G devices in or around your home (cordless phones, wireless LAN, wireless mouse, Bluetooth, etc) your 2.4G phone will have interference issues on one or more of the frequencies affecting signal, and therefore voice quality.
The more likely cause of the problem with digital cordless telephones is over processing, not compression. Simply, you have an analog signal (speaker and microphone on the handset) that are converted to digital to transmit over wireless which are then converted back to analog to pass on to the phone line which is really a port on your VOIP gateway which then takes that signal, digitizes it, compresses, packetizes it, sends it over the Internet with unpredictable delay, packet loss and jitter. Once the packets reach Vonage/Rogers or whoever they are reassembled, decompressed and sent over a digital telephone network to the other caller where it is converted back into an analog signal, or worse, back to IP, then back to analog, and over to another cordless phone at the far end.
The point is, each conversion along the path degrades the voice quality to some extent, so the more conversions that are introduced (even without compression) the more voice quality will be degraded.
BTW: Hi! I'm new here.