Why not only implement UDP and a ping service on the PIC (or whatelse there
    is needed). Appending data/commands at the end of the ping.

I thought you were at least peripherly interested in "conformance."  Adding
"user data" to ping packets (or ICMP in general) isn't allowed and wouldn't
count as conforming to much of anything.  Additionally, ICMP is frequently
supressed by all sorts of firewalls.

I don't think y'all are "getting it" with respect to emWare and similar
products.  Providing internet connectivity is only PART of such a
product.  A larger part (IMHO) is providing a supported web application
library.  emWare presumably (I have not looked at it in much detail)
allows an embedded designer to incorporate web-managed/available data
into their project WITHOUT them having to learn a bunch about internet
networking in general.  An open-source product might be useful for some
people, but is probably about as much use to emWare customers as a java
compiler is to basic stamp target audience.

For a stripped-down TCP/IP implementation on a microcontroller, I wouldn't
worry very much about "conformance" in a larger sense, as long as you are
"well behaved" within the scope of what you actually do.  Implementing
fragment reassembly is pretty pointless if your applications can limit
packet sizes to those which are very unlikely to be fragmented, for
instance.  ICMP support is a slightly thornier issue, but I think you
could do without it...

BillW
cisco