What is a MAN (Metropolitan Area Network)?

A Metro Area Network (MAN) geographically connects several nearby LANs (in an area of ​​about fifty kilometers) at high speed.  Therefore, a MAN allows two remote nodes to connect and communicate as if they were part of the same Local Area Network.

Source: What is a MAN (Metropolitan Area Network)? | SYSNETTECH Solutions

What is “=” in Cisco part number? – Cisco Community

A part with the = sign at the end is what is called a “FRU” part; where FRU stands for “Field Replaceable Units”. Those are the parts that can be used as “spare” or be shipped individually to replace damaged units. The new parts that are ordered directly from a reseller or from Cisco usually don’t come with the = sign.

Source: What is “=” in Cisco part number? – Cisco Community

Fiber Connector Type: SC APC vs SC UPC

Generally speaking, SC APC connector and SC UPC connector are distinct from each other based on fiber end face. SC APC connector is polished with an 8-degree angle, while SC UPC connector is polished with no angle, which causes difference in light reflection. SC UPC connector adopts an extended polish method to realize finer fiber surface finish, which brings much lower back reflection (ORL) and thus provides much more reliable signal in data center, digital TV and telephone. Although SC UPC connector has low insertion loss and wide range of application, there are some applications requiring for higher return loss, no less than 60 dB or even higher. In this circumstance, SC APC connector can make the need and consistently perform well due to the 8-degree angle

Source: Fiber Connector Type: SC APC vs SC UPC – Fiber Cabling Solution

Cabling the Spine-and-Leaf Network Switch Fabric | Optical Communications | Corning

As the size of networks grew during the last decade, we saw a shift from classical 3-tier network architectures to a flatter and wider spine-and-leaf architecture. With its fully meshed connectivity approach, spine-and-leaf architecture provided us the predictable high-speed network performance we were craving and also the reliability within our network switch fabric.

Source: Cabling the Spine-and-Leaf Network Switch Fabric | Optical Communications | Corning