Cisco IP Telephony Troubleshooting Guide for Cisco CallManager Release 3.0(1)
© 2000 Cisco Systems, Inc.
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The primary messages in the Skinny Station registration process are described in the following
table.
Skinny Station Registration Process Descriptions
Message Description
Station Register
The station sends this message to announce its existence to the
controlling Cisco CallManager.
Station Reset
Cisco CallManager sends this message to command the station to reset
its processes.
Station IP Port
The station sends this message to provide Cisco CallManager with the
UDP port to be used with the RTP stream.
Station Register
Acknowledge
Cisco CallManager sends this message to acknowledge the registration
of a station.
Station Register Reject
Cisco CallManager sends this message to reject a registration attempt
from the indicated phone.
char text[StationMaxDisplayTextSize];
};
Where:
text
is a character string, maximum length of 33 bytes, containing a
textual description of the reason that registration is rejected.
Station Capabilities
Request
Cisco CallManager sends this message to request the current
capabilities of the station. Station capabilities may include compression
standard and other H.323 capabilities.
Station Version Request
The station sends this message to request the version number of the
software load for the station.
Station Version Response
Cisco CallManager sends this message to inform the station of the
appropriate software version number.
Station Capabilities
Response
The station sends this message to Cisco CallManager in response to a
Station Capabilities Request. The station’s capabilities are cached in
the Cisco CallManager and used to negotiate terminal capabilities with
an H.323 compliant Terminal.
Station Button Template
Request
The station sends this message to request the button template
definition for that specific terminal or Cisco IP Phone.
Station Button Template
Response
Cisco CallManager sends this message to update the button template
information contained in the station.
Station Time Date Request
The station sends this message to request the current date and time for
internal usage and for displaying as a text string.
Station Define Time and
Date
Cisco CallManager uses this message to provide the date and time
information to the station. It provides time synchronization for the
stations.
Cisco IP Phone-to-Cisco IP Phone Call Flow within a Cluster
This section describes a Cisco IP Phone (directory number 1000) calling another Cisco IP Phone
(directory number 1001) within the same cluster. The cluster is a group of Cisco CallManagers
having one common Publisher SQL database and many Subscriber SQL databases.
In our sample topology, CCM1 is the publisher and CCM2 is a subscriber. The two
Cisco IP Phones (1000 and 1001) are registered to CCM1 and CCM2, respectively. The call flow
is shown in the diagram below. The two Cisco CallManagers within a cluster communicate with
each other using Intra-Cluster Control Protocol(ICCP). When a Cisco IP Phone goes off-hook ,
it opens a control Skinny Station session (with TCP as the underlying protocol) with the
Cisco CallManager. After call control signaling is established between the two Cisco IP Phones
