Cisco OL-9420-01 - Manual (Page 9)

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Troubleshooting Guide for Cisco Unified CallManager Release 5.0(2)
OL-9420-01
Appendix A Case Study: Troubleshooting Cisco Unified IP Phone Calls
Troubleshooting Intercluster Cisco Unified IP Phone Calls
16:05:45.312 CCM|StationD - stationOutputStartMediaTransmission tcpHandle=0x4fbb150 myIP:
e64610ac (172.16.70.230)
16:05:45.328 CCM|StationD - RemoteIpAddr: e74610ac (172.16.70.231) RemoteRtpPortNumber:
18448 msecPacketSize: 20 compressionType:(4)Media_Payload_G711Ulaw64k
16:05:46.203 CCM|StationInit - InboundStim - OnHookMessageID tcpHandle=0x4fbbc30
The calling party Cisco IP Phone finally goes on hook, which terminates all the control messages
between the Skinny Station and Cisco Unified CallManager as well as the RTP stream between Skinny
Stations.
16:05:46.203 CCM|StationInit - InboundStim - OnHookMessageID tcpHandle=0x4fbbc30
Troubleshooting Intercluster Cisco Unified IP Phone Calls
The case study in this section examines a Cisco Unified IP Phone that is calling another
Cisco Unified IP Phone that is located in a different cluster. This type of call is also known as an
intercluster Cisco Unified IP Phone call.
This section contains the following topics:
• Sample Topology
• Intercluster H.323 Communication
• Call Flow Traces
• Failed Call Flow
Sample Topology
The following sample topology gets used in this case study. Two clusters, each having two
Cisco Unified CallManagers, and also Cisco IOS Gateways and a Cisco IOS Gatekeeper are in place.
Intercluster H.323 Communication
The Cisco IP Phone in Cluster 1 makes a call to the Cisco Unified IP Phone in Cluster 2. Intercluster
Cisco Unified CallManager communication takes place using the H.323 Version 2 protocol. A
Cisco IOS Gatekeeper also serves for admission control.
The Cisco Unified IP Phone can connect to the Cisco Unified CallManager via Skinny Station protocol,
and the Cisco Unified CallManager can connect with the Cisco IOS Gatekeeper by using the H.323
Registration, Admission, and Status (RAS) protocol. The admission request message (ARQ) gets sent to
the Cisco IOS Gatekeeper, which sends the admission confirmed message (ACF) after making sure the
intercluster call can be made using H.323 version 2 protocol. Once this happens, the audio path gets
made by using the RTP protocol between Cisco Unified IP Phones in different clusters.
Call Flow Traces
This section discusses the call flow by using SDI trace examples captured in the CCM000000000 file.
The traces discussed in this case study focus only on the call flow itself.