We are planning to migrate to MS CRM Online. Although it will be an Online deployment of MS CRM, but the CRM application will be accessed by people from with in the office network only.
We have a scenario in which a plugin that will be hosted on MS CRM Online need to invoke a synchronous web service that is deployed on-premise (behind the firewall, only accessible via VPN or from within the office network).
What options do we have to connect to such synchronous on-premise web service from a plugin on MS CRM Online?