I'm integrating Salesforce opportunities to an internal network enterprise application.  To enable this integration (Apex Callout), will the enterprise application or target middleware need to be exposed to the internet?  If so, what is the best way to do this?

Also, I will need to create a Salesforce Web Service which can be called by the internal application.  I have created a sample one that works, however; my internal development partner would like me to modify the resulting WSDL to accept data in the exact format they are currently publishing it.  They have a company standard I need to adapt.  Without introducing middleware, is it possible for me to modify my web service to accept "exactly" what they are sending?  Also, is their any way I cannot require them to execute the Login method and retrieve a Session ID or is this always required?

I have a sample of their xml if that helps.

Any feedback will be appreciated!

Thanks!

I'm integrating Salesforce opportunities to an internal network enterprise application.  To enable this integration (Apex Callout), will the enterprise application or target middleware need to be exposed to the internet?  If so, what is the best way to do this?

Also, I will need to create a Salesforce Web Service which can be called by the internal application.  I have created a sample one that works, however; my internal development partner would like me to modify the resulting WSDL to accept data in the exact format they are currently publishing it.  They have a company standard I need to adapt.  Without introducing middleware, is it possible for me to modify my web service to accept "exactly" what they are sending?  Also, is their any way I cannot require them to execute the Login method and retrieve a Session ID or is this always required?

I have a sample of their xml if that helps.

Any feedback will be appreciated!

Thanks!