As we know, most SIP devices use SIP over UDP by default, however, some SIP servers or communication servers only support SIP over TCP. We have to say that’s really strange. Our customers need work with such devices and we upgrade MSS to V10.5 to support SIP over TCP to fit this requirement.
It is very easy to configure MSS to support this feature. If you are interesting in it, please refer to following document for more details about it: