A Starter Kit on VoIP
Confused about whether Voice over IP is the way for your business to go? You're not the only one. The technology has been gaining steam in the tech press during the past year, while federal lawmakers and regulators wrangle over who will have the regulatory upper hand.

Enterprise VoIP Planet
The IT Manager's Guide to Voice over IP

Softswitches.Part V: Media Gateway Control Protocol
Continuing our current tutorial series regarding softswitches, we have previously discussed the concepts of telephone switching, the architecture of a softswitch, the capabilities and functions of the media gateway controller, also known as call agent, that provides the call routing, network signaling, billing, and other logical functions within the network, plus the capabilities of the media gateway, that provides the physical connection to the local or wide area network.

SS7/IP Interworking Tutorial - Signaling
An overview of signaling information in IP telephony networks.

Understanding H.323.Part III: Signaling
Two standards are involved with H.323 signaling: H.225.0, Call Signaling Protocols and Media Stream Packetization for Packet-based Multimedia Communication Systems; and H.245, Control Protocol for Multimedia Communications, both of which are available from the ITU Web site.