Specifications

CHAPTER
5-1
Cisco MGX 8260 Command Line Interface Guide
Release 1.2, Part Number 78-10987-01 Rev. B0, January, 2002
5
Call Control
The MGX 8260 Media Gateway works in conjunction with Media Gateway Controller (MGC) servers
and the Public Switched Telephone Network (PSTN) to control voice and data calls.
Primary Call Control Components
The following components of the call control system are most important:
• Signal Transfer Point (STP)
STPs are components in the Signalling System 7 (SS7) network that route management traffic
between Service Switching Points (SSPs) and Service Control Points (SCPs).
• Central Office (CO)
The CO provides telephony services to subscribers and handles the associated management traffic.
The CO is often a SSP in the SS7 network.
• Media Gateway Controller (MGC)
An MGC, such as the VSC2700 Media Gateway Controller, communicates with the SS7 network
and MGX 8260 Media Gateways to process multimedia calls. These communications links can use
backhaul channels to adapt PSTN signaling to IP/ATM signaling.
• MGX 8260 Media Gateway
The MGX 8260 Media Gateway switches voice and data traffic between PSTN circuits and a packet
backbone, and it works with PSTN signaling points for voice call control and with MGCs for
multimedia call control. In addition, the MGX 8260 Media Gateway adapts PSTN signaling to
IP/ATM signaling so the MGC can control PSTN calls directly.
Primary MGX 8260 Call Control Interfaces
The MGX 8260 Media Gateway communicates with other media and signaling equipment through the
following interfaces:
• Integrated Services Digital Network (ISDN)
The MGX 8260 Media Gateway communicates with PSTN equipment using an ISDN (Integrated
Services Digital Network) D Channel of a Primary Rate Interface ISDN trunk. Within the
D Channel, multiple logical links may exist, which are defined by DLSAP and MACSAP profiles.