0

I have come across the term full and incomplete physical path several times in the context of whether a logical path is spanned by a full/incomplete physical path. I would like to understand and learn what this means and how it works.

I have one example below (you have to click on the image because some of the lettering may be blurry):

enter image description here

Apparently this is an example of the physical path "under" the Ethernet link not being full - because there is no connection between Connection Panel A.2 and Connection Panel B.2. If there was a connection there one could say that there are no gaps and the physical path for this Ethernet Link is complete.

I understand that for the physical path to be complete, the connection would have to go from Back B of Connection Panel A.2 to Front A of Connection Panel B.2 (or from Back A to Front B). Why is this the case? Does such an incomplete path change anything in practice? As far as I know Location A and Location B will have a connection through the Ethernet Link anyway (additionally, some connections are spanned - relationship between path and connection - red arrows/spans) - so I don't understand in what context a full and incomplete physical path is used. Could someone please explain this to me? Thanks in advance for any answer!

The diagram is from the training I was at, so I don't have a link unfortunately. It was shown in the context of distinguishing the physical path from the logical path (Ethernet Link). We have devices such as routers and connection panels (is a device with ports - optical or electrical - positioned directly on the device, that are used for pre-patching or for patching purposes), but instead of a router it could also be e.g. DWDM devices, and instead of connection panels - ODF devices.

8
  • It is unclear what kind of devices are in the diagram. Can you provide more context, such as a link or a quote from the diagram source?
    – Ron Trunk
    Nov 22 at 13:51
  • Sorry, I did not complete the name of one device. The diagram is from the training I was at, so I don't have a link unfortunately. It was shown in the context of distinguishing the physical path from the logical path (Ethernet Link). We have devices such as routers and connection panels (is a device with ports - optical or electrical - positioned directly on the device, that are used for pre-patching or for patching purposes), but instead of a router it could also be e.g. DWDM devices, and instead of connection panels - ODF devices.
    – MagicMan
    Nov 22 at 15:06
  • @RonTrunk (continuation) They said it would work on similar principle, it's just the idea with complete/not complete path
    – MagicMan
    Nov 22 at 15:07
  • Unfortunately, all "education, certification, or homework" questions are explicitly off-topic here. The correct answer is the one your class expects, not necessarily what may be reality or any answer you receive here.
    – Ron Maupin
    Nov 22 at 15:13
  • 1
    Without more context, that image means nothing. The physical path is the cabling between two ports. (including patch panels, etc.) A logical path is when there are devices completing the path between two devices. (eg. PC1 connects to SW1, PC2 to SW2. there must be a logical (and physical) path between SW1 & SW2 for the two PCs to exchange traffic. A logical path could be a vlan, pseudowire, etc.)
    – Ricky
    Nov 22 at 17:16