Cable Length Adding Parallel Paths Together

[jf5264835]

Deployment Type

Self-hosted

NetBox Version

v3.7.5

Python Version

3.10

Steps to Reproduce

1. Create device with interfaces.
2. Create a patch panel with front and rear ports.
3. Create second device with interfaces and second device with front and rear ports at different site.
4. Patch interface to 2 front ports of patch panel (Simulating the two individual strands of a duplex fiber cable)
5. Patch two rear ports from the first patch panel device to two rear ports of the second patch panel device.
6. Patch two front ports from second patch panel device to one interface of second device with interfaces.

Expected Behavior

Distance reported in total distance field should be 57426m, the length of 2m patch cable, a 3m patch cable, and 57,421m of dark fiber.

Observed Behavior

Total cable is being calculated as the sum of all cables, even when two cables are parallel runs where a duplex cable was broken into two simplex cables. For the purposes of specing optics and other gear the total distance is only 57.421km, not 114.847km. Screenshot below of cable trace.

[jeremystretch]

What if the two parallel cables have different lengths?

[jf5264835]

In that senario my thought would be that the two paths should then report two separate totals. The only time I can think that a total sum like this would be useful would be if one of the interfaces was unplugged and a loop back cable was installed for shooting the fiber with an OTDR.