Cisco 7975G Troubleshooting And Maintenance

Solution
When at least one person in a call does not receive audio, IP connectivity between phones is not established.
Check the configuration of routers and switches to ensure that IP connectivity is properly configured.
General Telephone Call Problems
This section describes troubleshooting of general telephone call problems.
VPN-Connected Phone Does Not Log Calls
Problem
A remote location (home office) phone that is connected through the VPN does not log missed, placed, or
received calls.
Cause
Without explicitly setting the Alternate TFTP setting, the Cisco IP Phone cannot contact the TFTP server and
download the configuration and other files, and function properly.
Solution
Set up the phone to use the Alternate TFTP server and configure the TFTP server IP address.
Related Topics
Set Up Remote Phone, on page 12
Phone Does Not Recognize DTMF Digits or Digits Are Delayed
Problem
The user complains that numbers are missed or delayed when the keypad is used.
Cause
Pressing the keys too quickly can result in missed or delayed digits.
Solution
Keys should not be pressed rapidly.
Troubleshooting Procedures
These procedures can be used to identify and correct problems.
Set Up Remote Phone
Cisco IP Phones that are configured for SSL VPN to ASA using the built-in client in a remote location (for
example, a home office) have a special configuration requirement.
Troubleshooting and Maintenance
12
Troubleshooting and Maintenance
General Telephone Call 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