I've been travelling up and down to London on the high-speed East Coast Main Line rail link quite a bit recently. It used to be GNER on the line, but now it's National Express.
In GNER's day, the plebs in standard class had to pay for the on-board WiFi access, but it was good, chugging away at around 300 Kbps upstream and down, using a combination of VSAT satellite and (presumably) multiple GPRS cellular modem connections.
National Express now offer the service in both classes, which is great, except that the GPRS facility seems to have been hit on the head. The system now seems to work purely across a VSAT satellite connection which downlinks into the Norwegian Internet network.
This convoluted route into t'Internet has two effects. Firstly the overall speed of the on-train WiFi connection has fallen to around 70 Kbps downstream and a staggeringly slow 20 Kbps upstream. Secondly the packet latency has gone to more than one second.
As well as being excruciatingly slow for email and Web surfing, this knocks value-added IP services such as VPNs and (don't laugh) VOIP firmly on the head owing to the packet time-outs on such services.
I've lost count of the number of peeps on the ECML who have given up trying to access their office VPN in disgust.
I've tried complaining to National Express via email and phone about this problem, but no-one seems to understand the technical nuances.
Mind you, I've only tried the standard class WiFi service. Perhaps the first class service is better? Grrrrrrrr...