Connecting to an IP WAN

The previous chapters have focused on Voice over IP (VoIP) within the IP network at a single site. The gateway in such a setup would interconnect public switched telephone network (PSTN), PBX, and other plain old telephone service (POTS) endpoints with voice-enabled IP endpoints, such as IP phones. VoIP over the WAN has several applications, such as connecting multiple sites, allowing service providers to terminate long-distance and local voice calls, providing voice services to telecommuters, and so on.

In this chapter you will learn

• Applications for connecting to an IP WAN
• Design considerations when using VoIP over an IP WAN
• Quality of Service issues and solutions
• Configuring Quality of Service to fit a provider's MPLS standards
• Providing fax and modem services within a VoIP network
• Ways to secure your VoIP traffic