OTM - Kewill threads /connections

Hey All, I have a question on OTM - Kewill Call . Do any one know when we make a rate request to Kewill How many threads or connection are opened to kewill - Is it like per rate request we have one thread opened in OTM and one connection made with Kewill or multiple rate request for each service level (Rate service) are part of single thread and single connection to kewill. I need it to make some assumptions about the capacity required for Kewill connections from OTM .