Configuring dial peers is the key to setting up dial plans and implementing voice in a VoIP network. In some situations, a router might also need to manipulate digits in a dial string before passing the dial string to a telephony device. For example, a 9 might need to be added to a dial string before the dial string passes out the router to a PBX, or perhaps a dialed area code and office code needs to be removed from a dial string. This chapter introduces plain old telephone service (POTS) and Voice over IP (VoIP) dial peers, which make an endtoend VoIP call possible. Additionally, this chapter discusses various approaches to manipulating dialed digits.
Consider a call center environment. Calls coming into a call center need to be distributed among available customer service agents. A hunt group takes calls coming into a single number and logically distributes those calls across hunt group members. This chapter also describes how to configure hunt groups and similarly how to reroute a call across the PSTN during times when an IP WAN connection is unavailable.
Finally, this chapter addresses the configuration of special purpose connections such as private line, automatic ringdown (PLAR) and connections that interconnect existing PBX systems.