Cisco IP Telephony Troubleshooting Guide for Cisco CallManager Release 3.0(1)
© 2000 Cisco Systems, Inc.
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and their respective Cisco CallManagers, the RTP stream starts flowing directly between the two
phones, as shown in the diagram below. The Skinny Station call flow messages for this intra-
cluster call are explained in next section.
Cisco IP Phone-to-Cisco IP Phone Exchange of Skinny Station Messages during Call Flow
The following figure shows a sample exchange of messages between two Skinny Stations. The
Skinny Station, or Cisco IP Phone, initiates a connection to the Cisco CallManager, and then
Cisco CallManager performs digit analysis before opening a control session with the destination
Skinny Station. As the following diagram indicates, the Skinny Station messages are written
using simple English so they can be readily understood by end-users. Because of this, these
messages are not explained in this section. However, these call flow Skinny Station messages are
explained in more detail in later sections when traces are being examined.