Nokia 9000i, so you had to work on CSD (which is usually billed per-minute, like dial-up), not even GPRS. How much did that cost you? :P
BTW, an interesting thing is that some/most carriers allow you to use CSD/HSCSD over 3G these days, and you can establish data CSD connection between two phone numbers, yielding essentially a dedicated L2 pipe which isn't routed over internet. Can have much lower latency and jitter if that's what you need. Some specialized telemetry is still using that, however as 3G is slowly getting phased out, it will probably have to change.
God, the cost was probably horrid, but I was connecting in, setting tasks running and logging out. This was late 1999 in the UK, so per-minute prices were high. Also, these were Windows servers, so I had to sluggishly RDP into them, no nice low-bandwidth terminals.
BTW, an interesting thing is that some/most carriers allow you to use CSD/HSCSD over 3G these days, and you can establish data CSD connection between two phone numbers, yielding essentially a dedicated L2 pipe which isn't routed over internet. Can have much lower latency and jitter if that's what you need. Some specialized telemetry is still using that, however as 3G is slowly getting phased out, it will probably have to change.