Cisco 7975G Troubleshooting And Maintenance

Physical Connection Problems
Problem
The physical connection to the LAN may be broken.
Solution
Verify that the Ethernet connection to which the Cisco Unified IP Phone connects is up. For example, check
whether the particular port or switch to which the phone connects is down and that the switch is not rebooting.
Also ensure that no cable breaks exist.
Intermittent Network Outages
Problem
Your network may be experiencing intermittent outages.
Solution
Intermittent network outages affect data and voice traffic differently. Your network might be experiencing
intermittent outages without detection. If so, data traffic can resend lost packets and verify that packets are
received and transmitted. However, voice traffic cannot recapture lost packets. Rather than retransmitting a
lost network connection, the phone resets and attempts to reconnect to the network. Contact the system
administrator for information on known problems in the voice network.
DHCP Setting Errors
Problem
The DHCP settings may be incorrect.
Solution
The following suggestions can help you determine if the phone has been properly configured to use DHCP:
1. Verify that you have properly configured the phone to use DHCP. For more information, see Network
Configuration Menu.
2. Verify that the DHCP server has been set up properly.
3. Verify the DHCP lease duration. Cisco recommends that you set it to 8 days.
Cisco Unified IP Phone 7971G-GE and 7970G send messages with request type 151 to renew their DHCP
address leases. If the DHCP server expects messages with request type 150, the lease will be denied,
forcing the Cisco Unified IP Phone 7971G-GE and 7970G to restart and request a new IP address from
the DHCP server.
Static IP Address Setting Errors
Problem
The static IP address assigned to the phone may be incorrect.
Troubleshooting and Maintenance
6
Troubleshooting and Maintenance
Physical Connection Problems

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