Cisco Cisco IOS Software Release 12.2(2)XA
MGCP 1.0 Including NCS 1.0 and TGCP 1.0 Profiles
Feature Overview
2
Cisco IOS Release 12.2(2)XA
Table 1
Feature Support by Platform
Feature Definition
Media Gateway Control Protocol (MGCP)1.0 is a protocol for the control of Voice over IP (VoIP) calls
by external call-control elements known as media gateway controllers (MGCs) or call agents (CAs). It
is described in the informational RFC2705, published by the Internet Society.
by external call-control elements known as media gateway controllers (MGCs) or call agents (CAs). It
is described in the informational RFC2705, published by the Internet Society.
PacketCable is an industry-wide initiative to develop interoperability standards for multimedia services
over cable facilities using packet technology. PacketCable developed the NCS and TGCP protocols,
which contain extensions and modifications to MGCP while preserving basic MGCP architecture and
constructs. NCS is designed for use with analog, single-line user equipment on residential gateways,
while TGCP is intended for use in VoIP-to-PSTN trunking gateways in a cable environment.
over cable facilities using packet technology. PacketCable developed the NCS and TGCP protocols,
which contain extensions and modifications to MGCP while preserving basic MGCP architecture and
constructs. NCS is designed for use with analog, single-line user equipment on residential gateways,
while TGCP is intended for use in VoIP-to-PSTN trunking gateways in a cable environment.
MGCP Model
MGCP bases its call control and intelligence in centralized call agents, also called media gateway
controllers. The call agents issue commands to simple, low-cost endpoints, which are housed in media
gateways (MGs), and they also receive event reports from the gateways. MGCP messages between call
agents and media gateways are sent over IP/UDP.
controllers. The call agents issue commands to simple, low-cost endpoints, which are housed in media
gateways (MGs), and they also receive event reports from the gateways. MGCP messages between call
agents and media gateways are sent over IP/UDP.
The MGCP 1.0 Including NCS 1.0 and TGCP 1.0 Profiles feature provides protocols for residential
gateways (RGWs) and trunking gateways (TGWs), which sit at the border of the packet network to
provide an interface between traditional, circuit-based voice services and the packet network.
Residential gateways offer a small number of analog line interfaces, while trunking gateways generally
manage a large number of digital trunk circuits.
gateways (RGWs) and trunking gateways (TGWs), which sit at the border of the packet network to
provide an interface between traditional, circuit-based voice services and the packet network.
Residential gateways offer a small number of analog line interfaces, while trunking gateways generally
manage a large number of digital trunk circuits.
Two basic MGCP constructs are endpoints and connections. An endpoint is a source or sink for call data
(RTP/IP) that is flowing through the gateway. A common type of endpoint is found at the physical
interface between the POTS or PSTN service and the gateway; this type of endpoint might be an analog
voice port or a digital DS0 group. There are other types of endpoints as well, and some are logical rather
than physical. An endpoint is identified by a two-part endpoint name that contains the name of the entity
on which it exists (for example, an access server or router) and the local name by which it is known (for
example, a port identifier).
(RTP/IP) that is flowing through the gateway. A common type of endpoint is found at the physical
interface between the POTS or PSTN service and the gateway; this type of endpoint might be an analog
voice port or a digital DS0 group. There are other types of endpoints as well, and some are logical rather
than physical. An endpoint is identified by a two-part endpoint name that contains the name of the entity
on which it exists (for example, an access server or router) and the local name by which it is known (for
example, a port identifier).
A connection is a temporary allocation of resources that enables a call to be completed. One or more
connections is necessary to complete a call. Connections have names that identify them with the call to
which they belong. Connections can be one-to-one or multipoint. Calls and connections are initiated,
modified, and deleted on instructions from call agents.
connections is necessary to complete a call. Connections have names that identify them with the call to
which they belong. Connections can be one-to-one or multipoint. Calls and connections are initiated,
modified, and deleted on instructions from call agents.
Call agents manage call flow through standard MGCP commands that are sent to the endpoints under
their control. The commands are delivered in standard ASCII text, and may contain session descriptions
transmitted in Session Description Protocol (SDP), a text-based protocol. These messages are sent over
IP/UDP.
their control. The commands are delivered in standard ASCII text, and may contain session descriptions
transmitted in Session Description Protocol (SDP), a text-based protocol. These messages are sent over
IP/UDP.
Call agents keep track of endpoint and connection status through the gateway’s reporting of standard
events that are detected from endpoints and connections. Call agents also direct gateways to apply
certain standard signals when a POTS/PSTN connection expects them. For example, when someone
events that are detected from endpoints and connections. Call agents also direct gateways to apply
certain standard signals when a POTS/PSTN connection expects them. For example, when someone
MGCP 1.0
TGCP 1.0
NCS 1.0
Cisco CVA122
Basic/Extended RGW
Basic/Extended RGW
Cisco uBR924
Basic/Extended RGW
Basic/Extended RGW
Cisco AS5300
ISUP, FGD-OS
ISUP, FGD-OS