NW Atlas line color change to indicate failure

There might be a way of adding a supplementary resource to the map, depending on what modules you're licensed for. If you had VNQM (VOIP and Network Quality Manager) you could create a ICMP echo operation between your important sites/nodes, and add this resource to the map alongside your links, giving you a logical view of the actual connectivity between the two.

DISCLAIMER: I have not got access to an instance of SW which has both NPM and VNQM installed at the moment to test this for you, so I cannot categorically confirm that VNQM resources can be added. However, since VNQM operations are Orion resources, stored in the Orion database, I would expect that they could be added to an Atlas map.