Document: draft-raj-dhc-tftp-addr-option-04.txt
Reviewer: Pete McCann
Review Date: 2008-12-23
IETF LC End Date: 2008-12-23

Summary: Ready, but a couple of comments.


This document is an attempt to codify existing behavior of some VoIP phones by re-naming the option number 150 as "VoIP Configuration Server Address option".
This field was previously known as the "TFT Server IP address" option.

A quick look at the IANA registry:

http://www.iana.org/assignments/bootp-dhcp-parameters/bootp-dhcp-paramet
ers.xhtml

reveals that Option 150 also has some other uses defined.  Also, it reveals that option number 128 is also listed as "TFTP Server IP address (for IP Phone software load)" and is overloaded with a few other uses.

The draft states that one reason for making this change is because some phones do not actually use TFTP to download their configurations, but still want to get an IP address from which to fetch the configuration.

I am a bit worried that a standard option won't be used with a standard downloading protocol.  It might be better for interoperability if the downloading protocol remains specified as part of the option.  Also, it seems a little strange to me to specify that a particular option is named after one application that might be run on a host.  However, maybe the horse has already left the barn and this option number is now specific to embedded VoIP phones rather than general purpose computers.