It was observed that in a network of routers, connectivity would be lost on some of the inter-router links after a number of days of operation. When this occurred, the control links displayed a large (and growing) number of undelivered messages outbound as though credit were exhausted on the link.
Other links remain open and the AMQP heartbeats flow such that the connection is never closed due to inactivity. This suggests that the problem is isolated to the control links only.
It is also observed that this problem only occurs when there is expiration of HELLOs causing topology changes.