Callback

Three types of call back are supported

• LCP (Link Control Protocol)
  After authentication the incoming call is dropped and an outgoing call is made to a predefined number to re-establish the link.

• Callback CP (Microsoft's Callback Control Protocol)
  After authentication from both ends, the incoming call is dropped and an outgoing call to a predefined number made to re-establish the link.

• Extended CBCP (Extended Callback Control Protocol)
  Similar to Callback CP however, the Microsoft application at the remote end will prompt for a telephone number. An outgoing call will then be made to that number to re-establish the link.

Domain Name Service (DNS) Proxy

Domain Name Service servers provide the translation of names such as www.avaya.com to the domain’s IP address required to establish a connection. IP Office provides this service to PCs on the network by proxy.

Network Address Translation (NAT)

Network Address Translation is a mechanism that allows you to use different IP address on your private  network behind a router with a public IP Address. When connecting to the Internet, ISPs typically want a customer to use an IP address they have allocated. Using NAT this is easily accommodated, eradicating the need for the customer to change their network numbering scheme and providing additional security to the internal users as their address in hidden to the public.

Typically, a company maps its internal network addresses to a global external IP address and unmaps the global IP address on incoming packets back into internal IP addresses. This helps ensure security since each outgoing or incoming request must go through a translation process. This also offers the opportunity to qualify or authenticate the request or match it to a previous request. NAT also conserves the number of global IP addresses that a company needs.