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Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter44 Configuring Inspection for Voice and Video Protocols
H.323 Inspection
For the local endpoint 10.130.56.4 and foreign host 172.30.254.205, there are 0 concurrent calls. This
means that there is no active call between the endpoints even though the H.225 session still exists. This
could happen if, at the time of the show h225 command, the call has already ended but the H.225 session
has not yet been deleted. Alternately, it could mean that the two endpoints still have a TCP connection
opened between them because they set “maintainConnection” to TRUE, so the session is kept open until
they set it to FALSE again, or until the session times out based on the H.225 timeout value in your
configuration.
Monitoring H.245 Sessions
The show h245 command displays information for H.245 sessions established across the ASA by
endpoints using slow start. Slow start is when the two endpoints of a call open another TCP control
channel for H.245. Fast start is where the H.245 messages are exchanged as part of the H.225 messages
on the H.225 control channel.) Along with the debug h323 h245 event, debug h323 h225 event, and
show local-host commands, this command is used for troubleshooting H.323 inspection engine issues.
The following is sample output from the show h245 command:
hostname# show h245
Total: 1
LOCAL TPKT FOREIGN TPKT
1 10.130.56.3/1041 0 172.30.254.203/1245 0
MEDIA: LCN 258 Foreign 172.30.254.203 RTP 49608 RTCP 49609
Local 10.130.56.3 RTP 49608 RTCP 49609
MEDIA: LCN 259 Foreign 172.30.254.203 RTP 49606 RTCP 49607
Local 10.130.56.3 RTP 49606 RTCP 49607
There is currently one H.245 control session active across the ASA. The local endpoint is 10.130.56.3,
and we are expecting the next packet from this endpoint to have a TPKT header because the TPKT value
is 0. The TKTP header is a 4-byte header preceding each H.225/H.245 message. It gives the length of
the message, including the 4-byte header. The foreign host endpoint is 172.30.254.203, and we are
expecting the next packet from this endpoint to have a TPKT header because the TPKT value is 0.
The media negotiated between these endpoints have an LCN of 258 with the foreign RTP IP address/port
pair of 172.30.254.203/49608 and an RTCP IP address/port of 172.30.254.203/49609 with a local RTP
IP address/port pair of 10.130.56.3/49608 and an RTCP port of 49609.
The second LCN of 259 has a foreign RTP IP address/port pair of 172.30.254.203/49606 and an RTCP
IP address/port pair of 172.30.254.203/49607 with a local RTP IP address/port pair of
10.130.56.3/49606 and RTCP port of 49607.
Monitoring H.323 RAS Sessions
The show h323-ras command displays information for H.323 RAS sessions established across the ASA
between a gatekeeper and its H.323 endpoint. Along with the debug h323 ras event and show local-host
commands, this command is used for troubleshooting H.323 RAS inspection engine issues.
The show h323-ras command displays connection information for troubleshooting H.323 inspection
engine issues. The following is sample output from the show h323-ras command:
hostname# show h323-ras
Total: 1
GK Caller
172.30.254.214 10.130.56.14
This output shows that there is one active registration between the gatekeeper 172.30.254.214 and its
client 10.130.56.14.