Running the iperf3 test against a three hop router configuration results in the number of streaming links on the inter-router connections to grow continually.
These links remain active and are never reclaimed, even after the iperf3 test clients and server exit.
To reproduce - establish 3 routers using the attached configuration. Run the iperf3 server:
iperf3 --server -p 8080 &
Run the iperf3 client several times, using many connections:
$ iperf3 -c 127.0.0.1 -p 8000 -P 100
Check the number of inter-router links:
$ qdstat -r RouterTcpA -l | grep inter-router | wc
422 8440 74272
The total number of links keeps increasing. It appears that each link still has some traffic on it - undelivered or unsettled messages - which will keep it from being reclaimed.