Spirent SmartBits System, Reference Manual

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Chapter 2: System Architecture
Traffic Generation and Performance Analysis
SmartBits System Reference 19
Traffic Generation and Performance Analysis
Each SmartBits port physically generates one frame at a time, at a user-defined rate. The
port traffic can be varied, tracked, and analyzed in different ways, depending on the
processor technology of each card (Traditional, SmartMetrics, or TeraMetrics).
The following terms will assist you in understanding SmartBits terminology:
•
Stream . A common template, pattern or packet structure based on a single protocol; a
single basic frame blueprint with a user-defined custom format or a selected standard
protocol format. A
stream acts like virtual host on a SmartBits card and simulates the
traffic of a workstation or server on a network. Depending on the processor types, the
individual frames may or may not have specialized tracking and reporting capabilities.
•
Traditional Stream . A single frame blueprint generated from a single port, with
varied frames generated via Variable Field Definitions (VFDs). These frames are
counted at the receiving ports but do not include a signature field for specialized
tracking.
•
SmartMetrics Stream . Retains its own signature field with a unique timestamp and
sequence ID and may generate many varied frames with specialized tracking and
reporting capabilities. The signature field is the mechanism for advanced tracking and
analysis methods, namely latency histograms, sequence tracking of every frame, and
raw tag reporting.
•
TeraMetrics Stream . Has SmartMetrics stream capabilities with special variations
available for very high speed technologies.
•
Flow . An industry-wide term referring to transmitted traffic sent from point A to point
B, tracked based on unique source and destination combinations. In SmartBits
products and documentation, this term is used as an abbreviation for the term
SmartFlow described below.
•
SmartFlow . A Spirent Communications term that is a superset of the above definition
of “flow.” A SmartFlow may include a single flow of traffic from point A to point B,
and may transmit many-to-one, one-to-many, or a set of different flows from either
receiving or transmitting ports for statistical analysis.
A SmartFlow is one or more frames from one or more sources to one or more destina-
tions that are tracked as a single entity. The sources and destinations can be defined at
the MAC, IP, TCP, or UDP level.