Troubleshooting guide

4-3
Cisco Broadband Local Integrated Services Solution Troubleshooting Guide
OL-5169-01
Chapter 4 Troubleshooting with Call Flows
Understanding MGCP
MGCP Commands
Table 4-1 describes the five commands (also called verbs) used by MGCP to make and terminate
connections between endpoints. All commands except Notify are sent by the Call Agent to the gateway.
Notify is sent from the gateway (which may also send a DeleteConnection).
MGCP Parameters
Parameter lines are composed of a parameter name (in most cases a single uppercase character), followed
by a colon, a space, and the parameter value. Table 4-2 lists parameters that can be present in requests
(M=mandatory, O=optional, F=forbidden).
.
The parameters are described in more detail in the following sections.
Table 4-1 MGCP Commands
Verb Code Used By Action
Notify NTFY Gateway Notifies the call agent of events.
Notification Request RQNT Call Agent Requests gateway to send notifications onoccurrence of
specified events in an endpoint, such as off-hook; or to
signal the caller, for example, play dial tone.
Create Connection CRCX Call Agent Sets up a new connection at the gateway.
Modify Connection MDCX Call Agent Modifies a gateway’s view of a connection, that is,
changes established connection parameters.
Delete Connection DLCX Call Agent Terminates a connection.
Table 4-2 MGCP Parameters
Parameter Name Code
Association of Parameters with Requests:
CRCX MDCX DLCX RQNT NTFY
Call Identifier C MMO F F
Connection Identifier I FMOF F
Request Identifier X OOOMM
Notified Entity N OOOOO
Local Connection Options L OMFFF
Connection Mode M MMFFF
Requested Events R OOOOF
Signal Requests S OOOOF
Digit Map D OOOOF
Observed Events O FFFFM
Connection Parameters P FFOFF
Reason Code E FFOFF