MetadataService url in plugin on IFD

Hi,

I have a plugin which is called during a workflow, the workflow is failing on the plugin with an ssl/tls error. I think this is because i am using the method 'this._metaService = context.CreateMetadataService();' and it is pulling the url as https://localhost/mscrmservices/2007/metadataservice.asmx . Where does the method get this url from and how can I assure it either calls an http url which works or https://<servername>:port/mscrmservices/2007/metadataservice.asmx

Thanks