IP Phone ERROR 7960

Answered Question
Apr 19th, 2009

My IP phone will not download the software from the TFTP on the CME Router.

This is the error it has now. Protocol Application Invalid

Everything was working fine before. Does any one know how I can fix this issue?

Correct Answer by Paolo Bevilacqua about 7 years 10 months ago

Yes. More exactly, since the layer 3 switch will actually route traffic between data and voice vlan, the ccme router will use subinterfaces only to communicate with devices in said vlans.

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Overall Rating: 5 (1 ratings)
Charlie Mayes Mon, 04/20/2009 - 07:14

I performed a Factory reset but, did not run that debug yesterday. I will try it this evening. Have you seen this before? What did you do to fix it?

Charlie Mayes Mon, 04/20/2009 - 07:24

Thanks. I will do it and hopefully this lead me in the right direction. Is this a common problem with Cisco phones?

Charlie Mayes Mon, 04/20/2009 - 08:26

I understand. I bought these phones off Ebay and hopefully will not need any software to reload the whole phone. If I do what do you suggest? I have an AUX port on this phone. How do I interface the phone via the AUX port if I can not login to it via IP? Do I need some special type of cable? I am new to this whole voice thing. Sorry for all the questions.

Paolo Bevilacqua Mon, 04/20/2009 - 09:01

You absolutely need the sccp firmware for the phones, any version will will do.

The AUX port is not used for logging in and does not help you in restoring the phones.

Paolo Bevilacqua Mon, 04/20/2009 - 12:01

You buy a support contract (aka smartnet) for the phone, either online or from a dealer, then you're allowed downloads.

Charlie Mayes Tue, 04/21/2009 - 04:07

I got a chance to run the debug tftp events after plugging up my ip phone lastnight. I plugged up my working phone and saw the tftp download the working phone requested from the debug. I then plugged up the phone that has the Protocol Application Invalid Error and did not see were it looks for a tftp server via the debug running on the router. Is the phone broken or something? When ever I reset it to factory default after rebooting it goes to configuring ip then goes to the Protocol Application Invalid Error after a couple of minutes.

Paolo Bevilacqua Tue, 04/21/2009 - 05:20

Are you choosing the delete config at the reset menu ?

Do you have no debug output whatsoever when you that ?

Charlie Mayes Tue, 04/21/2009 - 05:24

Yes I am choosing the erase config option

Option 1 is to save the current Config the on Phone

Option 2 is to erase the current Config on Phone

I always select Option 2

As far as the the debug I get no output what so ever from the router when I boot the phone with the Protocol Application Invalid Error.

Paolo Bevilacqua Tue, 04/21/2009 - 05:38

Do you have DHCP with option 150 ?

Also I suggest you connect phone to a PC with TFTPD32 and wireshark for further analysis.

I'e never seen a phone that cannot be recovered being persistent enough.

Charlie Mayes Tue, 04/21/2009 - 05:45

Yes, I have configured my Windows DHCP server with the option 150 TFTP and even entered the IP address of the tftp server. I will do the wireshark thing tonight. Should I be using the Native data vlan or the voice VLAN when I do this? My other phone is on VLAN 1 Data Vlan and it has no problems.

Paolo Bevilacqua Thu, 04/23/2009 - 10:44

You should use the the voice vlan, but if everything fails, connect directly to a PC and no VLANs.

Charlie Mayes Thu, 04/23/2009 - 10:47

Do you have any information on how to properly setup a voice vlan so that the phones get their ip address different from the data vlan?

Paolo Bevilacqua Thu, 04/23/2009 - 13:09

On a cisco switch:

interface x/y

switchport mode access

switchport access vlan ZZ

switchport voice vlan XX

Charlie Mayes Thu, 04/23/2009 - 14:21

I mean if I have 2 DHCP pools how does the ip phone now what pool to get the ip address from? I am confused about how the layer 3 device would know how to route everything. I understand the config above but, am missing what needs to be configured on my 3550 layer 3 switch.

Paolo Bevilacqua Fri, 04/24/2009 - 05:38

When the phones initially sends CDP, the switch understand there is a phone and they agree to use a tagged voice vlan for all phone activities. No configuration is necessary beside the one I gave you before. If you want inter-vlan routing done by the switch (recomended), just configure its vlan address as default gw in dhcp.

It is recommended that you keep the dhcp server for phones on the cme router, this way you don't have any dependency to a server and can easily configure, and monitor the entire boot process of a phone in a single place.

Charlie Mayes Fri, 04/24/2009 - 06:39

Thanks so much Nick I think this finally makes sense to me. I guess I would have to setup subinterfaces on my router in order to run route data traffic and voice traffic right.

Correct Answer
Paolo Bevilacqua Fri, 04/24/2009 - 10:51

Yes. More exactly, since the layer 3 switch will actually route traffic between data and voice vlan, the ccme router will use subinterfaces only to communicate with devices in said vlans.

Please remember to rate useful posts with the scrollbox below.

Charlie Mayes Fri, 04/24/2009 - 11:07

Thanks for everything you have done to help me. I surely will leave you a rating. Thanks Again Nick.


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