Cisco Cisco IOS Software Release 12.4(23)
678
Caveats for Cisco IOS Release 12.4
OL-7656-15 Rev. J0
Resolved Caveats—Cisco IOS Release 12.4(5c)
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CSCsb93407
Symptoms: When H323 call service stops, the router still listens on TCP port 1720 and completes
connection attempts.
connection attempts.
Conditions: This symptom occurs after H323 is disabled using the following configuration
commands:
commands:
voice service voip h323 call service stop
Workaround: Access can be blocked by deploying an interface access list that blocks access to TCP
port 1720 for traffic that is destined for any of the IP addresses of the router.
port 1720 for traffic that is destined for any of the IP addresses of the router.
For information about deploying access lists, see the “Transit Access Control Lists: Filtering at Your
Edge” document at
Edge” document at
For further information about deploying access lists, see the “Protecting Your Core: Infrastructure
Protection Access Control Lists” document at
Protection Access Control Lists” document at
For information about using control plane policing to block access to TCP port 1720, see the
“Deploying Control Plane Policing White Paper” at
“Deploying Control Plane Policing White Paper” at
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CSCsc12255
Symptoms: When you deploy VoIP on an NM-HDV2 network module that is configured with a
PVDM2-64 module, a hissing sound may be heard before the ringback tone starts on the calling side.
PVDM2-64 module, a hissing sound may be heard before the ringback tone starts on the calling side.
Conditions: This symptom is observed only with an NM-HDV2 network module. Note that the
symptom does not occur with an NM-HDV network module.
symptom does not occur with an NM-HDV network module.
Workaround: There is no workaround.
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CSCsc72722
Symptoms: TCP connections that are opened through a Cisco IOS Firewall (CBAC) may not
timeout.
timeout.
Conditions: With Cisco IOS Firewall (CBAC) enabled, the TCP idle timer for a session may be reset
even by TCP packets that fail TCP inspection and are subsequently dropped. This could lead to the
TCP session not timing out.
even by TCP packets that fail TCP inspection and are subsequently dropped. This could lead to the
TCP session not timing out.
Workaround: There is no workaround.
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CSCsc95234
Symptoms: When the stcapp global configuration command is enabled, the command is not
accepted and the following error messages are generated:
accepted and the following error messages are generated:
STCAPP: Internal error: Unable to create codec list... exiting
stcapp shutdown initiated... waiting for calls to clear.
stcapp shutdown complete.
Conditions: This symptom is observed on a Cisco router that runs Cisco IOS interim
Release 12.4(6.3) but may also affect Release 12.4T.
Release 12.4(6.3) but may also affect Release 12.4T.
Workaround: There is no workaround.
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CSCsc97398
Symptoms: The user information Layer 1 protocol may be included in the outgoing bearer capability
and may be set to either G711 u-law or G711 A-law. Some PBXs may refuse the call because of this
mismatch in the bearer capability.
and may be set to either G711 u-law or G711 A-law. Some PBXs may refuse the call because of this
mismatch in the bearer capability.
Conditions: This symptom is observed when a call is made from H.323 to ISDN with unrestricted
digital information bearer capability.
digital information bearer capability.
Workaround: There is no workaround.