SoapException or output parameter?

Hi,

If an error occurs in the back-end system of a webservice how should this be
communicated to the consumer of the webservice?

One way is to raise an SoapException for the consumer client to catch, and
this works fine for .NET clients, but will it work equally well for other
types of clints?

Another solution is to return any error descriptions and/or error codes
through a simple output parameters.

Pros and cons?

Thanks
Erik