Comments on No Good Tips & Tricks: Hacking The Cisco 7940 IP Phone

Will altering the TFTP server in the phone have an...

2011-03-25T10:06:15.393-04:00

Will altering the TFTP server in the phone have any negative consequences operationally? Not going to touch policy... lol

Will this require the tftp server to be running constantly for the ringtone to work? Will it error our otherwise?

Also, what happens when my pc is off and it can't contact the tftp, will it default to a ringtone?

Thanks!

Mm.. Look nice . But unfortunately i don't kno...

2011-01-06T12:46:59.339-05:00

Mm.. Look nice . But unfortunately i don't know what is cisco mobile.

A bit late here, but does anyone know which config...

2010-09-29T18:43:22.963-04:00

A bit late here, but does anyone know which config file/setting carries the equivalent of the "Disable Settings Access" checkbox that is available in the Cisco Call Manager? I would assume the value would have to be sent to the phone to work, but I just don't see anything appropriate in the files I can pull from tftp. We would like to lock down the ringtone setting after customizing it, but do not have access to the call manager.

-thanks

I have managed to successfully upload and play a r...

2010-01-22T11:12:36.942-05:00

I have managed to successfully upload and play a ringtone that was 8.25 secs long. It seems that the only issue is the size of the file compared to available memory on the selected phone. Perhaps.
64.5kb file worked, 66.5kb did not.

This is all on a Cisco 7940
Model: CP-7940G
Firmware: 8.0(9.0)

Alternate TFTP server program, as suggested by the Cisco Site
http://tftpd32.jounin.net/tftpd32_faq.html

Hi Daniel, I'm really sorry about not replyin...

2009-11-08T20:41:02.570-05:00

Hi Daniel,

I'm really sorry about not replying earlier, I've been busy with grad school.

I'm not sure about where to get these files since I was trying stuff out on my desk phone at work and I had access to the TFTP server.

I'd suggest VoIP-Info.org, a Wiki where people who are interested in 'all things VoIP' collaborate. You will probably find someone who can help you out there. The page for the Cisco IP Phones is here

hello, May be you can help me. I bought a 7940 in ...

2009-10-05T22:11:31.432-04:00

hello, May be you can help me. I bought a 7940 in ebay, and it is like in a hung state showing Protocol Application Invalid.
I can see the phone trying to download the files from the tftp server, the issue is that I don't have these files.
Cisco requires a maintenance contract to download the conf files. Do you know where I can get those files?

That sox command only works on an older version of...

2009-05-21T15:09:46.232-04:00

That sox command only works on an older version of sox. The latest version (as is provided in the link) accecpts the following command:

sox sound.wav -t raw -r 8000 -U -c 1 sound.raw rate -l

Whoops... that dd command above should read: dd i...

2009-05-20T19:49:03.056-04:00

Whoops... that dd command above should read:

dd if=sound.raw of=sound.trimmed.raw bs=240 count=67

Which means "read from sound.raw, write to sound.trimmed.raw 67 blocks of 240 bytes each"

The Cisco document you link to in regards to the f...

2009-05-20T19:42:36.524-04:00

The Cisco document you link to in regards to the format of the soundfile implies that the sound file can only be ~2 seconds in length (16080 samples / 8000 samples per second = 2.01).

I have successfully loaded a ringtone that is over three seconds in length. That limitation may be dependant upon your phone model/firmware version.

My phone is a 7940 with firmware version 8.0(10.0).

The bullet points about the number of samples being evenly divisible by 240 bears some explanation. If your ringtone isn't divisible by 240, you'll hear a click at the end of playback. The same goes for the file ending at the zero crossing.

To overcome these problems, I edit my sound files in audacity (http://audacity.sourceforge.net/download/) and use the Generate->Silence... menu option and pad the ending (and beginning, as needed) with silence. This satisfies the requirement that the file begins and ends at the zero crossing. Otherwise, you get clicks at the beginning or end of playback.

I then trim the file down to a reasonable length (if the sound is really short, like < 1 sec., my phone tries to play it twice per ring. That sounded annoying with the 1-UP sound from Mario 3, so I added extra padding at the end to stretch it out) and save it as a .wav file.

The next steps are borrowed from another blog which I cannot locate at the moment:

I use the SOX command-line audio editor (http://sox.sourceforge.net/) to convert the file from .wav to U-Law.

The command-line looks like this:

sox sound.wav -t raw -r 8000 -U -b -c 1 sound.raw resample -ql

Then I use the dd command (http://gnuwin32.sourceforge.net/packages/coreutils.htm for you poor Windows users) to trim the file such that the filesize is divisible by 240.

Remembering that there are 8 bits per sample, the file size in bytes equals the number of samples. That means that we can divide the file size by 240 to see how many blocks of 240 bytes the final file should have.

The dd command to create a file of exactly 16080 samples looks like this:

dd if=sound.raw of=sound.trimmed.raw bs=24 count=67

Thank you for a great and informative post!

@andy: You certainly can jump to the options but I...

2009-03-31T13:46:00.000-04:00

@andy: You certainly can jump to the options but I didn't want to complicate the write-up further. And also, I wanted to avoid a situation where Cisco decided to add/remove some options and thus, changed the order in the menu! That would render the steps useless to someone who didn't quite understand what to do.

I did try re-enabling telnet using the config files, but that didn't work. If you find something, do let me know!Here's the Cisco page for the file parameters: http://www.cisco.com/en/US/docs/ios/12_3/vvf_c/cisco_ios_sip_security_application_guide/SIPSecAp.html

And I"m glad it helped you in some way :)

You can jump to the relevant menu options by typin...

2009-03-27T12:31:00.000-04:00

You can jump to the relevant menu options by typing the number (ie 3 4 to get to Item 34)

You can probably re-enable telnet by changing one of the config files that's pulled by tftp ;-)

Thanks for the place to start

Cheers
Andy

@Sam Hall: No, sorry, I didn't try that.

@s...

2009-02-05T08:58:00.000-05:00

@Sam Hall: No, sorry, I didn't try that.

@shockboi: My phone has telnet disabled; probably by our company sysadmin. But that's a cool trick :)

@Anonymous: I'm not sure; doesn't it require the user to select the option?

You can push xml-documents to the phone to make it...

2009-02-05T02:42:00.000-05:00

You can push xml-documents to the phone to make it call out etc. See

http://www.cisco.com/en/US/docs/voice_ip_comm/cuipph/all_models/xsi/6_0/english/programming/guide/xsi60obj.html#wp1033829

Get the IP of the phone. Telnet into it. Default p...

2009-01-29T19:59:00.000-05:00

Get the IP of the phone. Telnet into it. Default password is lowercase "cisco". From there you can access commands enabling you to dial and so on. Cant recall what they are exactly but if you type a ? you get a listing of available commands. You can play the "hang up" game with your co workers too, which is amusing for about 5 mins. Remote into their phone, and hang up their calls. Its hell funny.

I'm trying to find out if there is a way to dial a...

2008-12-08T20:59:00.000-05:00

I'm trying to find out if there is a way to dial a number on this phone from your PC. Did you ever look into this?

I don't think it's possible, but if it is that would be very handy.

hi, thank you for this great information

re...

2008-08-27T02:09:00.000-04:00

hi, thank you for this great information

regards,
Meki Chan
Cisco Trick

You can also use the free TFTP Server from PacketT...

2008-06-05T12:29:00.000-04:00

You can also use the free TFTP Server from PacketTrap. You can get it at www.PacketTrap.com/download. I find it more intuitive and faster than the solarwinds product.