Cisco 7941G Troubleshooting And Maintenance

Table 4: Changes to Voice Quality Metrics
ConditionMetric change
Network impairment from packet loss or high jitter:
• Average MOS LQK decreases could indicate
widespread and uniform impairment.
• Individual MOS LQK decreases indicate bursty
impairment.
Cross-check with Conceal Ratio and Conceal Seconds
for evidence of packet loss and jitter.
MOS LQK scores decrease significantly
Check to see whether the phone is using a different
codec than expected (RxType and TxType).
Check to see whether the MOS LQK version changed
after a firmware upgrade.
MOS LQK scores decrease significantly
• Network impairment from packet loss or high
jitter.
Conceal Ratio and Conceal Seconds increase
significantly
Noise or distortion in the audio channel such as echo
or audio levels.
Tandem calls that undergo multiple encode/decode,
such as calls to a cellular network or calling card
network.
Acoustic problems coming from a speakerphone,
handsfree cellular phone, or wireless headset.
Check packet transmit (TxCnt) and packet receive
(RxCnt) counters to verify that voice packets are
flowing.
Conceal Ratio is near or at zero, but the voice quality
is poor.
Voice quality metrics do not account for noise or distortion, only frame loss.
Note
Cisco Unified IP Phone Cleaning
To clean your Cisco Unified IP phone, use a soft, dry cloth to wipe the phone screen. Do not apply liquids or
powders directly on the phone. As with all non-weather-proof electronics, liquids and powders can damage
the components and cause failures.
Disable the screen before cleaning it so that you will not inadvertently choose a feature from the pressure of
the cleaning cloth. To disable the screen, press Display for more than one second. The phone displays
Touchscreen Disabled or Phone Screen Disabled and the Display button flashes green.
After one minute, the screen automatically reenables itself. To reenable the screen before that, press the
flashing Display button for more than one second. The phone displays Touchscreen Enabled or Phone
Screen Enabled.
Troubleshooting and Maintenance
25
Troubleshooting and Maintenance
Cisco Unified IP Phone Cleaning

Cisco 7941G Specifications

General

Keypad number of keys	12
Touchscreen	-
Display resolution	320 x 222 pixels
Speakerphone	Yes
Voice codecs	G.729a
Bluetooth	No
Supported network protocols	DHCP, TFTP, SCCP, DSCP
Ethernet LAN (RJ-45) ports	2
Input voltage	48 V
Dimensions (WxDxH)	266.7 x 152.4 x 203.2 mm
Storage temperature (T-T)	-10 - 60 °C
Operating temperature (T-T)	0 - 40 °C
Operating relative humidity (H-H)	10 - 95 %
Handset type	Wired handset
Product type	IP Phone
Product color	Gray
Safety	(UL) 60950, (CSA) C22.2 No. 60950, IEC 60950, EN 60950, AS/NZS 60950
Certification	CE (FCC) 15 (CFR 47) B ICES-003 B EN55022 B CISPR22 B AS/NZ 3548 B VCCI B EN55024 EN 50082-1 EN 61000-3-2 EN 61000-3-3
Compliance industry standards	IEEE 802.3, IEEE 802.3u, IEEE 802.1Q, IEEE 802.3af
Lines quantity	- lines
Phonebook capacity	- entries
Number of handles included	1 pc(s)

Weight and Dimensions

Weight	1600 g