soap in smsbox

Hello,

I want to implement a soap interface in the smsbox.

As far as I know, there is no real sms over soap standard.
If someone knows a soap interface that is frequently used, please inform 
me, then I implement that one,
but as far as I have seen now every smsc provider that uses a soap 
interface has its own soap definition.

When no one has a better suggestion I want to make a wsdl, which has one 
action:
SendSms
and the possible (sometimes optional) parameters:
user, pass, from, to, tolist, udh, smsc, mclass, mwi,
coding, compress, validity, deferred, dlr_mask, dlr_url,
account, rpi, charset, binfo, priority

someone has suggestions to add or remove params?

Jaap