13.2 RELATIONSHIP OF SERVICES TO THE LAYERS
13.2.1 Service Requirements and How They Affect
Technologies of the Layers
Network services are provided by network overlays at each layer. Each layer then
places requirements on lower layers all the way down to the optical layer. Service
requirements differ by the type of service and layer where they are provided. Service
requirements can be divided into two basic classes: (1) expectations for provisioning
new services or features of existing services, including bandwidth constraints/
options, and (2) Quality-of-Service (QoS) parameters, such as Bit Error Rate
(BER), packet loss, latency/delay, jitter. As one would expect, all of these require-
ments can differ by network segment, layer, and type of servic ...