[Asterisk-Users] 7940/60 TFTP Problem

[Rich Adamson]

> I was wondering if anyone else has had this problem.  I have purchused several Cisco 
7940 and 7960 phones.  Of the 5 phones so far I have run accross 2 that that give me 
malformed TFTP and refuse to upgrade to the latest version of SIP code -- 5.3.  In fact 
some of the other phones also give malformed packets do this but they seem to work OK.  
The ones giving me the problem when looking in ethereal are misiing part of the filename 
to get it upgraded to SIP.
> 
> I know why it does not work, but why are these malformed packets apearing.  I also tried 
to go to a windows based TFTP server (original was linux TFTP) with the same results.
> 
> Any ideas anyone?

Without specific error codes, packet traces, etc, we can only guess.
Some real options include:

a) not all tftp servers are the same. Over about 15 years of experience, 
many tftp servers have an issue with the last packet and how to close
the session. Might research the exact software you're using.

b) the cisco phones seem to have an issue with the "comment" lines in the
SIPDefault file (on the tftp server). Remove every one and test again.
This seems to be highly dependent on the exact versions of SIP code
implemented (in sequence) from v2.x upward. Some phones seem to have the
problem while others don't. 

Since we don't know what version of code was in the phone when you received
it, best guess is to boot to v2.x, then 3.x, then 4.x, then 5.x and I'll
bet (at least a beer) the problem disappears. Why? don't know, but lots
of similar comments on the list.