VOIP handsets
 

Has anybody had any experience using these (and a service like Skype or Vonage) to keep in touch when travelling abroad? I know the headsets are available and work, but the handset (with a USB connection to the laptop, or better still wireless with a usb connected remote station) is more comfortable.

By the way, the only place I see them on sale is eBay! I was in Shanghai recently and tried the local electronics stores and nothing to be found there either! Any ideas where to find them at reasonable prices? Also, your experiences in using them over dialup and broadband environments will help me decide whether to go for a pair..

Thanks in advance.

I use both Vonage and Skype when travelling abroad. If I have a fast connection I prefer to use Vonage (the softphone), but over slower connections Skype works better. I tried using Skype over a dial up, but it was pretty choppy. Most of my calls are made using the Wifi connection on my portable, and I use my t-mobile hotspot account. Generally my experiences have been favorable, and you can't beat the price!

I use a headset, so I can't help you with the handset issue.

Hope this helps.

I use an IP phone all the time when working from my home office. But it is a full function IP desk phone and connects to our corporate VoIP system via an IPSec VPN tunnel. When I am travelling, I carry a Plantronics USB folding headset and us a softphone on my PC. Again, this requires an IPSec VPN tunnel between my PC and our corporate network. This allows me to make local calls to my family and friends back home, even when I am overseas. It really confuses people with CLID when they know I am in the USA and my calling number shows the call originated from Sydney. And its way cheaper than making international calls from a hotel phone, even if I have to pay for the hotel's broadband internet access.

So the technology can certainly work well over the public internet using hotel broadband internet access. But there are times when congestion causes quality issues. You need to be aware that you are using public infrastructure for your call and bandwidth is not assured. I have used mine regularly between USA and Australia (ie the IP session is going trans-Pacific) as well as between various countries in Asia/Europe and Australia without any major latency issues. And with the IPSec encryption in the path, the one-way latency is regularly significantly more than the IETF recommendation of 150ms max.

Also note that a VoIP call using the G.723 CODEC (64Kbps PCM) requires at least 96Kbps when carried in IP. And if you need to encrypt the IP data then you are going to need better than 120Kbps. A G.729 CODEC requires approx 50Kbps unencrypted and about 80Kbps if encrpted. The extra 52 bytes header for an IPSec wrapper result in a significant overhead when carrying the small Voice packets. If you don't need to encrypt your voice traffic, then don't. Even without encryption you are not going to be successful over a dialup modem, you will need broadband. I often use Hotel WiFi internet access with my softphone quite successfully.