Skip to main content
CallTower Solutions Center

Cisco 79XX - Troubleshoot MPLS/Circuit/ASA

  1. Last updated
  2. Save as PDF

Goal

To help the end-user troubleshoot the phone.  This requires someone physically on-site to assist in the troubleshooting process.

Resolution/Steps

  1. Confirm the phone has power, indicated by the phone screen lighting up/displaying information
    • If the customer's network provides power over Ethernet (PoE), the network cable should be firmly seated in the 10/100 SW port
    • If the customer's network doesn't provide PoE, there should be a power cable for an appropriate power supply firmly seated in the DC48V port
  2. Confirm the model of the phone
    • This can be retrieved from Settings, Model Information (4), Model Number (1)
    • This may be able to be retrieved from the top right-hand corner of the phone screen frame
    • This may be able to be retrieved from the back of the phone, above the kickstand, on a sticker towards the top right, under the screw socket/hole
  3. Confirm the MAC address of the phone
    • This can be retrieved from Settings, Model Information (4), MAC Address (2)
    • This may be able to be retrieved from the back of the phone, under the kickstand, from the MAC sticker section
  4. Confirm the phone is built-in CallTower Connect
    • Now that you have the phone model and MAC, you can confirm the phone is showing built-in Connect
      • Go to the Phones section in CallTower Connect:
      • Connect Menu Phones.PNG
      • Search the MAC to confirm it's built.
      • MAC Search.PNG
  5. Confirm the phone is built-in Cisco Unified Communications Manager (Call Manager/CUCM)
    • Now that you have the phone model and MAC, you can confirm the phone is showing built-in CUCM
    • You will need to know what Call Manager Cluster the customer is built on.
      • In CallTower Connect on the "Customers" page you can expand the page and under "Customer Details" it has the cluster under "CM Resource"
        • "Customers" Menu:  Connect Menu Customers.PNG
        • "Customer Details" and "CM Resource"
          • Connect Cluster.PNG
  6. Confirm the phone is connecting to the network
    • The IP address can be retrieved from Settings, Network Configuration (3), IP Address (6)

Intermediate troubleshooting (by symptom)

Network connection unavailable/Configuring IP
  1. Review the IP address of the phone, Basic troubleshooting step 6
    • Phone should have a 10.252.X.X (Customer managed LAN), 10.253.X.X (Sprint MPLS), 10.254.X.X (CallTower MPLS) IP address
    • The phone should have a 192.168.22.X (ASA) IP address
    • IP's listed are "default", a customer could have custom IP range, review account SHN
    • If the phone has any other IP, it is most likely connected to the wrong network
  2. Erase the Network Configuration
    • Settings, highlight Network Configuration, more, Erase
    • If Erase is "gray", use **# to unlock the settings
  3. Review the IP address of the phone
    • The phone should now be getting a valid IP if connected to the right LAN, this portion of troubleshooting is complete
    • If the phone is displaying 0.0.0.0, proceed to the next appropriate step 
  4. Confirm cabling
    • Confirm network cable is firmly seated in the 10/100 SW port on the phone, and the other end into the customers LAN
    • The phone should grab an IP within 2-3 minutes, see step 3
  5. Rule out the network cable
    • Use another/known working network cable if available, see step 4
  6. Rule out network port
    • Move the phone to a known working network port where an existing phone is currently registered, see step 4
  7. Rule out network topology (network equipment/patch panel/cable run)
    • Connect the phone directly to the DHCP server if possible, see step 4
  8. At this point, if the phone is still failing to get an IP address, it will need to be reviewed by a Tier 2 or Tier 3.
Registering/Registration rejected

  1. Confirm the correct model/MAC is built-in Connect and CUCM

    • See Basic troubleshooting steps 2 and 3

    • If incorrect, rebuild the phone with the correct model/MAC, otherwise, proceed to step 2

  2. Review Alternate TFTP settings

    • Navigate to Settings, Network Configuration (3), Alternate TFTP (32), Should be set to NO

    • Use **# to unlock the settings and update to NO if needed

    • If Alternate TFTP is currently set to NO or was updated to NO, and the phone is still failing to register, proceed to step 3

    • Phones should not need to have TFTP set to YES, DHCP opt 150 should be configured on the ASA/router to provide the correct CUCM cluster

  3. Clear the ITL/CTL file(s)

    • Navigate to Settings, Security Configuration (6), highlight ITL/CTL

    • If either the ITL/CTL file are listed with anything other than "Not Installed", erase the entries

    • Use **# to unlock the settings if needed

    • Erasing the ITL or CTL file will clear both if present, and should reboot the phone

  4. At this point, if the phone is still failing to register, it will need to be reviewed by T2+

Phone stuck in a boot loop
  1. Confirm the correct model/MAC is built-in Connect and CUCM
    • See Basic troubleshooting steps 2 and 3
  2. Factory reset the phone
    • See attached document Factory Reset 7900 Series IP Phones for Cisco documentation on this process
  3. At this point, if the phone is still stuck in a boot loop, it will need to be reviewed by T2+

Additional Information

What's next?

If there are any symptoms outside of the scope of this document, or any items that need clarification, please reach out/escalate to a Tier 2.

Common Issues/Related Articles

Factory Reset:  

79XX Features: