We analyze the performance of TCP and TCP with
network coding (TCP/NC) in lossy wireless networks. We build
upon the simple framework introduced by Padhye et al. and
characterize the throughput behavior of classical TCP as well as
TCP/NC as a function of erasure rate, round-trip time, maximum
window size, and duration of the connection. Our analytical
results show that network coding masks erasures and losses
from TCP, thus preventing TCPs performance degradation in
lossy networks, such as wireless networks. It is further seen
that TCP/NC has significant throughput gains over TCP. In
addition, we simulate TCP and TCP/NC to verify our analysis of
the average throughput and the window evolution. Our analysis
and simulation results show very close concordance and support
that TCP/NC is robust against erasures. TCP/NC is not only
able to increase its window size faster but also to maintain a
large window size despite losses within the network, whereas
TCP experiences window closing essentially because losses are
mistakenly attributed to congestion.