O'Reilly logo

Metro Ethernet by Sam Halabi

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

U
unidirectional path switched ring (UPSR).

Path-switched SONET rings that employ redundant, fiber-optic transmission facilities in a pair configuration. One fiber transmits in one direction, and the backup fiber transmits in the other. If the primary ring fails, the backup takes over.

unnumbered link.

A link that does not have an IP address assigned to it.

User-to-Network Interface (UNI).

A specification of the interface between an end system and a backbone system. An example is the specification of an Ethernet interface that connects a switch at the customer site and a router at the provider site.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required