Cisco Systems ATA 186 Telephone User Manual


 
4-4
Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide for MGCP (version 3.0)
OL-4803-01
Chapter 4 Cisco ATA-Supported MGCP Services
Additional MGCP Services
MGCP Endpoint Device Type
To request the device type from the Cisco ATA, the Call Agent must use the following syntax in the
RequestedInfo (F:) parameter line of an AUEP command:
F: X-UA
The Cisco ATA responds with the following device-type:
X-UA: Cisco/ATA186
Call Agent Redundancy with Configuration Parameters
Call Agent (CA) redundancy is supported in two ways. You can use the following sets of parameters to
configure the primary and secondary CA IP addresses or URLs:
CA0orCM0, page 5-12, and CA0UID, page 5-13
CA1orCM1, page 5-13, and CA1UID, page 5-14
If the CA is identified with the format CallAgentName@HostName, enter the CA name in the CAxUID
parameter and enter the HostName in the CAxorCMx parameter (x is 0 or 1).
If the CA is identified using a URL, enter the URL in the CAxorCMx parameter. An optional port
number can also be entered in the format CAxorCMx:Port# (x is 0 or 1).
When the Cisco ATA power ups or performs a configuration update, it tries to contact the primary CA
at CA0orCM0. If there is no response or the address is not reachable, the Cisco ATA then tries to contact
the secondary CA. The Cisco ATA continues to alternate attempts to contact the primary and secondary
CAs until it gets a response.
If the CAxorCMx parameter is configured with a URL, the Cisco ATA contacts the DNS server to
resolve the name. The Cisco ATA accepts up to four IP addresses from the DNS server. During
operation, if contact is lost between the Cisco ATA and its CA, the Cisco ATA uses an exponential
timeout period on each attempt to reach the CA at the IP addresses. The Cisco ATA cycles through the
IP addresses until it gets a response.
Cisco ATA Registration Process with MGCP
When the Cisco ATA powers up, each MGCP endpoint is in a disconnected state. The Cisco ATA sends
a Restart in Progress (RSIP) command for each MGCP endpoint to the preconfigured Call Agent using
one of the following syntax definitions, selected by using Bit 24 in the ConnectMode parameter (see the
“ConnectMode” section on page 5-24):
Syntax Type 1
RSIP EPID0@ip_address MGCPVersion
RM: restart
and
RSIP EPID1@ip_address MGCPVersion
RM: restart