Hello, we have a FreeSWITCH instance running on a IBM XSeries 32 bit server machine with a Windows 2003 operating system (RAM 6 GB). Our business logic is written in C# and integrated as a DLL module. Our module is originating the call via Native.Api DLL. With this solution we could make up to 30 parallel calls without any problems (calling a number, playing a wav file, hang up). If we increase the parallel call count to 100, we have problems with the sound (choppy) and the originate command returns with NO_ANSWER in many cases, but the callee has successfully answered (we have got many feedbacks, why we are calling but not speaking). In some documents and maillist postings we readed out, that freeswitch can handle more than 1000 sessions. Are this numbers only for linux machines? What are the limits of parallel calls with a Windows server and how we could increase the performance? Which environment is recommend for use FreeSWITCH with bulk calls? Does the .NET environment is blocking freeswitch while working? Best regards Ali