Lightning LND - Send Payment Both Ways Within Same Channel Me and my friend are testing Raspibolt running LND 0.6 Beta. We noticed the following problem/limitation:


When I opened a channel with him, I could send him payments (via invoice) without any problems (direct connection). But when he tried to pay me (via invoice), the transaction tried to go through other nodes rather than going directly to my node. Then we closed the channel and tried the other way around. He opened a channel with my node and I could receive payments from him but I couldn't send him any payments directly. Transaction one again tried to go through other nodes.


Why is this happening?
The Problem here is the channel reserve. If you fund a channel all the bitcoin are on your side. At this point you can only pay. However let us assume you make a really small payment (below 1% of the channel capacity) your channel partner can't pay you back on that channel. After establishment lightning channels are required to keep at least 1% of the capacity on their side. If it was less it would incentivice the person owning no or only little liquidity to breach to protocol an publish and old channel state. Since the punishment would do basically no other harm then having a channel closed. 

I suspect this is what happened between your two nodes. Try to balance the channel a little bit more by sending over 10% of your funds and sending back 5%. if that does work then we found the problem.