Dear Bluezers, I am working on contrcuting a simple relay scatternet with CSR-based USB dongle. Yesterday I made it that 4 dongle relay data from top to down and dwon to top, writing a utility code based on rfcomm program in bluez-util. I works fine! A ------------------>B-----------------> C ------------------> D M S M S M S But, while I am running it serveral time. I got a one difficult problem "Can't bind: Address already in Use!" This is old problem in TCP/IP socket program, when the server clashes without close the socket, so that the well-kown (or fixed anyway) cannot be resused again for a several minutes in typical TCP/IP socket program. But! what is the port in rfcomm socket? Is this channel numer? or board address?. And Can I use socketopt system call for the rfcomm socket ? for RESUSE option! Also, the socket address is not freed for even 30 minutes, while usually TCP/IP port is can be resued after several minutes! What part of kernel stack has something with this??? rfcomm.o ???? Please kindly comment this. Thanks.