  We introduce a protocol to distribute entanglement between remote parties.
Our protocol is based on a chain of repeater stations, and exploits topological
encoding to tolerate very high levels of defects and errors. The repeater
stations may employ probabilistic entanglement operations which usually fail;
ours is the first protocol to explicitly allow for technologies of this kind.
Given an error rate between stations in excess of 10%, arbitrarily long range
high fidelity entanglement distribution is possible even if the heralded
failure rate within the stations is as high as 99%, providing that unheralded
errors are low (order 0.01%).
