> > I don't post here often but I read with interest all the postings. - I've > > been on a lot of mailing lists, but this one is by far the most interesting. > > > > I've been doing a lot of work with 'tftp' loading Cisco 79xx phones with > > firmware, configs. for asterisk, etc. > > > > And I see where a lot of folks have trouble with 'tftp', use alternate port > > numbers (probably to get around firewall issues), etc. - And I've even seen > > where some folks complain that 'tftp' is one of the 'worst' protocols on the > > Internet. > > > > At the end of this posting, I've included a little tid-bit on > > 'primary/alternate' 'tftp' servers for the Cisco 79xx phone setup. > > > > This next part is mainly for 'newbies' who are new to asterisk & haven't got > > a clue as to what 'tftp' is. - Advanced users, geeks, etc., please disregard > > the next part if you want. > > > > Apologize in advance if this is boring. > > > > Going back to 'Networking 101', just exactly what is 'tftp'? - Is there any > > reason WHY it came into being in the first place? > > > > 'tftp' stands for 'Trivial File Transfer Protocol'. - Unlike the more > > popular 'ftp' protocol, 'tftp' is considered 'non-secure'. - Meaning that no > > login name/password challenge is require. - The 'device' (computer, phone, > > whatever) sends a request to the 'tftp' server for the file & the server > > sends it. - Plain and simple. > > > > 'tftp' also uses the 'UDP' (User Datagram Protocol). - The main difference > > between 'UDP' and 'TCP' is that 'UDP' uses NO ERROR CORRECTION. - No 'acks' > > & 'naks' to make sure all the packets arrive okay at the receiving end. - > > It's up the receiving end to make sure everything was received okay. > > It also makes it relatively simpler for someone on the same LAN (mostly) > to fake being a tftp server for that client (or vice versa). A UDP > packet is generally more predictable, so if I wanted to send the phone > bogus firmware or bogus config, it would generally be easier for me than > if the server has read the files using, e.g. HTTP. > > HTTP is simple, well-supported and supports all the "file transfers" > operations TFTP supports.
And, FWIW, there are a large number of tftp implementations (mostly in the non-linux pc arena) that have issues dealing with the last packet in a tftp transfer causing failures. (Based on about 15 years of using various tftp products as a mechanism to upgrade cisco ios's.) _______________________________________________ Asterisk-Users mailing list [email protected] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
