Hello
We used to use the Swisscom GSM number - 0794998990 - but a couple of months ago, it got unstable, so I took another look. Now we're using the regular landline SMSC 0622100000, which works very well.
But you can only send SMS if you're a swisscom customer, so they can charge the SMS on your invoice.
I belive glue.ch still offers TSP independent SMSSC Services if you regster at them.
-Benoit-