1. There are two annoying incompetence of TCP. One is that
TCP does not distinguish packet loss caused by network
transmission error from that caused by network congestion.
The congestion control and avoidance mechanism makes TCP
drop its transmit window upon detecting a packet loss,
thus lowers the transmit rate even if the loss is caused
by physical link transmit error.
This results in an unnecessary reduction in link
bandwidth utilization, especially in the environment of
wireless physical links.
The Performance Implications of Link Characteristics (PILC) working group
has been exploring this.
(http://www.ietf.org/html.charters/pilc-charter.html) See
draft-ietf-pilc-error-06.txt and draft-ietf-pilc-link-design-04.txt for a
discussion of ways to ameliorate performance issues that don't require an
alternative to TCP. Bottom line recommendation: implement forward error
correction to improve noisy links, don't require the world to adopt a new
TCP.