NimX      Thin Trunk Interface      PTX      Benefits

Prior to Nimcat, SMEs had two alternatives when choosing the appropriate architecture for their call processing needs: they could either choose a PBX installed on their premises or a hosted Centrex solution. Nimcat has introduced the next generation architecture - PTX - that leverages the increased processing power of VoIP chips and the emergence of standard communication protocols, such as SIP.

  • Private Branch Exchange (PBX)
  • Centrex (CTX)
  • Peer Telephony eXchange (PTX)


A PBX is a central piece of equipment, usually located on the premises of a business. It provides all of the call processing intelligence between the different terminals, such as voicemail and auto-attendant. As well, it as acts as the gateway between the internal network and the external public domain.

Equipment vendors often have to sell their PBX at very low margins, since the high cost of the central equipment is prohibitive when addressing SMEs.


Centrex is a service offered by the majority of Service Providers. CTX provides functions and features comparable to those of a PBX. The difference lies in the location of this central piece of equipment. In the CTX architecture, the switch is located on the premises of the Service Provider and can handle the call processing needs of multiple business clients.

Although the high cost of a CTX switch can be shared amongst several business clients, this architecture is limited in customer flexibility, often requires large maintenance and support expenditures, and has extensive traffic on the Service Provider network. End-Customers are charged a high monthly fee for every line connected to the CTX switch.


Peer Telephony eXchange (PTX) also known as Peer-to-Peer (P2P) call processing takes the intelligence usually found in CTX and distributes it to the end-user telephone sets. Each phone recognizes the other terminals on the network and instantly forms a trusted network with the ability to interact with its peers, as well as connect to the PSTN or any WAN VoIP channel.

Nimcat has leveraged this architecture to properly address SMEs By eliminating the need of the central piece of equipment, Nimcat has developed a low cost solution that is simple to install and maintain, and more importantly, easy to use.