Looking at it in a little bit more detail specific to the VoIP development kit, the solution used in this kit is based on open-source Linux, kernel 2.6. Also, the core control and signaling has been provided by NXP’s partner, Arcturus, using their middleware solution. The solution has been based, as much as possible, on open SIP resulting in some open-source portions being present. Unfortunately, the open-source solution does not have all the functionality required. The rest of the functionality is filled in with proprietary software from Arcturus.