Cisco Systems 8945, 8941 manual Halfduxcollisionexceedthreshold

Chapter

General Troubleshooting Tips

Table 9-2	Cisco Unified IP Phone Troubleshooting (continued)
Summary		Explanation
Sound sample mismatch between the		The RxSize and the TxSize statistics show the size of the voice packets that are
phone and another device.		being used in a conversation between this Cisco Unified IP phone and the other
		device. The values of these statistics should match.
		See the “Call Statistics Screen” section on page 7-8for information about
		displaying these statistics.
Gaps in voice calls.		Check the AvgJtr and the MaxJtr statistics. A large variance between these
		statistics might indicate a problem with jitter on the network or periodic high
		rates of network activity.
		See the “Call Statistics Screen” section on page 7-8for information about
		displaying these statistics.
Loopback condition.		A loopback condition can occur when the following conditions are met:
		• The SW Port Configuration option in the Network Setup menu on the
		phone is set to 10 Half
		(10-BaseT / half duplex)
		• The phone receives power from an external power supply
		• The phone is powered down (the power supply is disconnected)
		In this case, the switch port on the phone can become disabled and the
		following message will appear in the switch console log:
		HALF_DUX_COLLISION_EXCEED_THRESHOLD
		To resolve this problem, re-enable the port from the switch.
One-way audio.		When at least one person in a call does not receive audio, IP connectivity
		between phones is not established. Check the configurations in routers and
		switches to ensure that IP connectivity is properly configured.
Phone call cannot be established		The phone does not have a DHCP IP address, is unable to register to Cisco
		Unified Communications Manager, and shows a Configuring IP or Registering
		message.
		Verify the following:
		1. The Ethernet cable is attached.
		2. The Cisco CallManager service is running on the Cisco Unified
		Communications Manager server.
		3. Both phones are registered to the same Cisco Unified Communications
		Manager.
		4. Audio server debug and capture logs are enabled for both phones. If
		needed, enable Java debug.

	Cisco Unified IP Phone 8941 and 8945 Administration Guide for Cisco Unified Communications Manager 8.5 (SCCP and SIP)
OL-20851-01		9-11