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Cisco Telepresence System - Replacing or installing CP 7975 or CP 7970 phone issues



CP-7975 or CP 7970 Physical phone conditions:

Phone is constantly cycling after install and or showing nothing on the screen


Only shows the 3LED buttons scrolling upon boot and nothing else.. Just hangs


Phone is unresponsive after power cycle.

Most common reason is the phone load itself  as well as a misunderstanding of the phone load process explained below

For example: Direct upgrade to 9.x phone load from 8.3.2 SCCP default  phone load for a new factory phone or replacement depot phone.

It may work sometimes but it is not recommended to upgrade directly from the factory codec 8.3.2 SCCP to a later 9.x phone load

CUCM conditions:

After either resetting to phone defaults or installing a new phone the IP Phone is stuck upgrading

The phone displays upgrading and never upgrades.

The IP Phone CUCM device configuration will show the phone in one of the conditions shown below:

Phone shows "Unregistered" or "Unknown"   or "Rejected"

CUCM--->Unified CM admin---> Device--->Phone

CTS GUI conditions:

1) Under system status screen showing Red "X" for room phone

Conditions / Environment

Cisco Unified IP Phone does not register but CTS registers fine

Replacing or installation of a CP 7975 or 7970 Telepresence phone


Cause / Problem Description

Most common reason for this issue is the phone load itself

Please do NOT power cycle the phone while upgrading...explanation below

Most common reason for damaging the phone HW is to power cycle during upgrade.

IP Phone will not upgrade to default CUCM load

Root Cause:   IP Phones are shipped with 8.3(2) SCCP phone load from depot

The upgrade from 8.3(2) SCCP or TERM loads to 8.4.4 SIP is a two step process.

ALSO please note the following:

Per 1.7 Release notes:

Resetting the Cisco Unified IP Phone 7975 Factory Image (Firmware damage caused by power cycle during upgrade)

Occasionally, an unexpected phone power cycle can occur during a CTS endpoint upgrade.

During CTS endpoint upgrades, the CTS briefly powers off the phone then brings it back up when upgrade is complete.

But if the phone power cycle is occurring  at the same time, the phone's firmware image can be damaged and the  phone will not power back on.

This can also occur when upgrading the phone MIDlet.

To avoid this problem, unplug the phone before upgrading the CTS endpoint.

When upgrade is complete, plug the phone back in and upgrade the MIDlet.

If you encounter a phone that will not power back  on after a CTS endpoint or MIDlet upgrade, perform a phone factory reset  to restore the firmware image. For more information, see the Resetting  the Cisco Unified IP Phone 7970 Series Factory Image section of the Cisco Unified Communications Manager Configuration Guide for the Cisco TelePresence System.

PLEASE allow the phone load upgrade to complete to avoid causing damage to the Cisco 79xx phone.

Work around: Its possible  to recover the phone in this condition by  attempting to hook the CP  79xx phone to another external wall jack with PoE set for DHCP to see if  it will attempt the upgrade.

Please allow time to complete.


Workaround   Upgrade firmware in two phases:

First , upgrade the firmware to 8.4(4) SIP phone load

Second, upgrade firmware from 8.4(4) SIP phone load to any higher phone load

Plug the phone directly into the network port to bypass the codec to rule out any issue with the codec.

2. Power cycle the phone.

3. If the problem persists, contact TAC for assistance.

When  upgrading the phone please make sure to restart the TFTP service on CUCM if not done so already after uploading the file.

To restart the TFTP service on CUCM:

•Cisco Unified Serviceababilty


•“Control Featured Service”

•Service “Cisco TFTP”

•“Restart” at bottom of the page

•NOTE: Make sure phone load is loaded on CUCM Pub and any Subs in the cluster

              The Codec SW and the phone loads need to be uploaded on each CUCM in the cluster for it is NOT automatically

              copied from the Pub to any of the Subs unlike config changes.

CUCM config for phone load:

Phone load name is configured either on the "Device information  field itself on the Device profile (CUCM-->CM  Admin--->Device--->Phone)

or in the "Device Defaults" (CUCM-->CM admin-->Device-->Device Defaults)

Note: If the Device profile "Phone load name" is left blank it will then go to the Device Defaults

Steps to replace CP 7975 phone:

•1) Phone from depot comes with “8.3.2 SCCP” phone load

•2) Upgrade first to “8.4.4 SIP” code by creating SIP profile first

•3) Unlock phone with “**#” and go to “Network settings” if necessary

If setting to Static IP on phone:

Static IP settings on phone…

•Set the “DHCP” settings (IPV4 config) “disable” DHCP

•Set “IP address” and “Subnet Mask”

•Set “Default route”

•Then scroll down to bottom for “TFTP Server 1” Set to CUCM IP address where code is stored

•4) Once set connect phone and apply config and reset the phone.

Should  take about 5-10 min to load 8.4.4 SIP phone load

•NOTE: Should see on phone “Upgrading”

•Note: Wait till phone registered and showing as loading 8.4.4.SIP  can verify with CGI screenshot and or CUCM Device Info and CTS DUI  System info

•Then once registered subscribe midlets and again the phone should reload… 5-10 min

Follow the same steps above for upgrading to later code for example 9.2.1

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