Cisco 7975G Troubleshooting And Maintenance

To verify that the phone is in the Cisco Unified Communications Manager database, choose Device > Phone>
Find from Cisco Unified Communications Manager Administration to search for the phone based on the
MAC Address. For information about determining a MAC address, see Cisco Unified IP Phone MAC Address
Determination.
If the phone is already in the Cisco Unified Communications Manager database, its configuration file may be
damaged. See Configuration File Corruption, on page 4 for assistance.
Cisco Unified IP Phone Cannot Obtain IP Address
Problem
If a phone cannot obtain an IP address when it starts up, the phone may not be on the same network or VLAN
as the DHCP server, or the switch port to which the phone connects may be disabled.
Solution
Ensure that the network or VLAN to which the phone connects has access to the DHCP server, and ensure
that the switch port is enabled.
Cisco Unified IP Phone Displays Security Error Message
Problem
The phone displays “Security Error” on the screen.
Cause
When a Cisco Unified IP Phone boots, it performs an internal Power On Self Test (POST). POST checks for
existing encryption functionality. If POST detects that encryption functionality is missing, the phone fails to
boot, and the message “Security Error” appears on the screen.
Solution
To correct the problem, perform the following steps:
1. Reset the phone manually.
2. If the phone does not start up properly, power up the phone with the handset off-hook. When the phone
is powered up in this way, it attempts to launch a backup software image.
3. If the phone still does not start up properly, perform a factory reset of the phone. For instructions, see
Factory Reset, on page 20.
Cisco Unified IP Phone Resets Unexpectedly
If users report that their phones are resetting during calls or while idle on their desk, you should investigate
the cause. If the network connection and Cisco Unified Communications Manager connection are stable, a
Cisco Unified IP Phone should not reset on its own.
Typically, a phone resets if it has problems connecting to the Ethernet network or to
Cisco Unified Communications Manager. These sections can help you identify the cause of a phone resetting
in your network:
Troubleshooting and Maintenance
5
Troubleshooting and Maintenance
Cisco Unified IP Phone Cannot Obtain IP Address

Cisco 7975G Specifications

General

Handset type	Wired handset
Product type	IP Phone
Product color	Grey, Silver
Speakerphone	Yes
Voice codecs	G.711Mu, G.711a, G.722, G.729A, iLBC
Number of melodies	24
Aspect ratio	4:3
Display diagonal	5.6 \
Display resolution	320 x 240 pixels
Lines quantity	8 lines
Phonebook capacity	- entries
Number of VoIP accounts	-
Front camera	No
Security algorithms	128-bit AES
Networking standards	IEEE 802.1Q, IEEE 802.1p, IEEE 802.1x, IEEE 802.3af
Ethernet LAN data rates	10, 100, 1000 Mbit/s
Ethernet LAN interface type	Gigabit Ethernet
Supported network protocols	DHCP, TFTP
Volume control	Digital
Headphone outputs	1
Ethernet LAN (RJ-45) ports	2
Number of handles included	1 pc(s)
AC adapter output voltage	48 V
Storage temperature (T-T)	-10 - 60 °C
Operating temperature (T-T)	0 - 40 °C
Operating relative humidity (H-H)	10 - 95 %
Certification	FCC

Weight and Dimensions

Depth	152.4 mm
Width	266.7 mm
Height	203.2 mm
Weight	1600 g