I have learned a lot in the past two months in the networking field but more specifically, I'm starting to slowly but surely understand concepts pass the CCNA Level of things. The Cisco CCNA Certification merely goes into any sort of depth about the WAN side of things. The past two months I have already dealt with many LECs (Local Exchange Carriers) regarding different types of circuits . While it has been mainly T1's with a few Frame Relay/MPLS circuits I am starting to understand the importance of knowing WAN topology concepts. Understanding where the Demark is for the carrier to the customer is very important. Also knowing the different types of symptoms that cause a circuit to do down is even more important.
Funny enough the most common thing that causes a circuit to go down isn't anything related to the line or equipment itself. Mother nature herself is the #1 reason circuits go down rather it's because of a massive thunderstorm or a tree falling and damaging the fiber lines. Believe it or not, many times a line will go down because of a tractor rolling over the cable! You would think that carriers would bury the lines deeper but oh well. I hope in the next 4 months to have the WAN concepts down pretty good from a topology stand point, this will help a ton for preparation for CCNP.