Cisco IP Telephony Troubleshooting Guide for Cisco CallManager Release 3.0(1)
© 2000 Cisco Systems, Inc.
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15:20:21.421 CCM|StationD - stationOutputCallInfo CallingPartyName=1001, CallingParty=1001,
CalledPartyName=, CalledParty=3333, tcpHandle=0x5138d98
Before reviewing the following traces, it is important to understand the meaning of the term
H.323. By way of a brief explanation, there are several protocols that are used when establishing
an H.323 session. One protocol is H.225, which is primarily used for call signaling and is a
subset of Q.931. Another protocol is H.245, which is used for capability exchange. One of the
more important functions of H.245 is the Compressor/Decompressor (codec) type negotiation,
such as G.711, G.729, and so on, between the calling and called side. Once the capability
exchange is complete, the next important function of H.245 is performing a UDP port
negotiation between the calling and called sides.
The following trace shows that the H.323 code has been initialized and is sending an H.225 setup
message. You can also see the traditional HDLC SAPI messages, the IP address of the called
side in hex, and the port numbers.
15:20:21.421 CCM|Out Message -- H225SetupMsg -- Protocol= H225Protocol
15:20:21.421 CCM|MMan_Id= 1. (iep= 0 dsl= 0 sapi= 0 ces= 0 IpAddr=e24610ac IpPort=47110)
The following trace shows the calling and called party information as well as the H.225 alerting
message. Also shown is the mapping of a Cisco IP Phone’s hex value to the IP address.
172.16.70.231 is the IP address of the Cisco IP Phone (1001).
15:20:21.437 CCM|StationD - stationOutputCallInfo CallingPartyName=1001, CallingParty=1001,
CalledPartyName=, CalledParty=3333, tcpHandle=0x5138d98
15:20:21.453 CCM|In Message -- H225AlertMsg -- Protocol= H225Protocol
15:20:21.953 CCM|StationD - stationOutputOpenReceiveChannel tcpHandle=0x5138d98 myIP:
e74610ac (172.16.70.231)
The following trace shows the compression type used for this call (G.711 µ-law).
15:20:21.953 CCM|StationD - ConferenceID: 0 msecPacketSize: 20
compressionType:(4)Media_Payload_G711Ulaw64k
Once the H.225 alert message has been sent, the next part of H.323 is initialize: H.245. The
following trace shows the calling and called party information, and the H.245 messages. Notice
the TCP handle value is the same as before, indicating this is the continuation of the same call.
15:20:22.062 CCM|H245Interface(3) paths established ip = e74610ac, port = 23752
15:20:22.062 CCM|H245Interface(3) OLC outgoing confirm ip = e24610ac, port = 16758
15:20:22.062 CCM|MediaManager - wait_AuConnectInfo - received response, forwarding
The following trace shows the H.225 connect message, as well as other information that was
explained earlier. When the H.225 connect message is received, the call has been connected.
15:20:22.968 CCM|In Message -- H225ConnectMsg -- Protocol= H225Protocol
15:20:22.968 CCM|StationD - stationOutputCallInfo CallingPartyName=1001, CallingParty=1001,
CalledPartyName=, CalledParty=3333, tcpHandle=0x5138d98
15:20:22.062 CCM|MediaCoordinator - wait_AuConnectInfoInd
