Cisco Ip Phone-To-Cisco Ip Phone Call Flow Within A Cluster - Cisco 30 VIP Troubleshooting Manual

Cisco IP Telephony Troubleshooting Guide for Cisco CallManager Release 3.0(1)
The primary messages in the Skinny Station registration process are described in the following
table.
Skinny Station Registration Process Descriptions
Message
Station Register
Station Reset
Station IP Port
Station Register
Acknowledge
Station Register Reject
Station Capabilities
Request
Station Version Request
Station Version Response
Station Capabilities
Response
Station Button Template
Request
Station Button Template
Response
Station Time Date Request
Station Define Time and
Date

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
© 2000 Cisco Systems, Inc.
Description
The station sends this message to announce its existence to the
controlling Cisco CallManager.
Cisco CallManager sends this message to command the station to reset
its processes.
The station sends this message to provide Cisco CallManager with the
UDP port to be used with the RTP stream.
Cisco CallManager sends this message to acknowledge the registration
of a station.
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.
Cisco CallManager sends this message to request the current
capabilities of the station. Station capabilities may include compression
standard and other H.323 capabilities.
The station sends this message to request the version number of the
software load for the station.
Cisco CallManager sends this message to inform the station of the
appropriate software version number.
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.
The station sends this message to request the button template
definition for that specific terminal or Cisco IP Phone.
Cisco CallManager sends this message to update the button template
information contained in the station.
The station sends this message to request the current date and time for
internal usage and for displaying as a text string.
Cisco CallManager uses this message to provide the date and time
information to the station. It provides time synchronization for the
stations.
53