IP load testers are a class of
protocol analyzer
A protocol analyzer is a tool (hardware or software) used to capture and analyze signals and data traffic over a communication channel. Such a channel varies from a local computer bus to a satellite link, that provides a means of communication usi ...
s focused on the practical evaluation of
router performance. Router performance is usually broken down into two categories:
forwarding performance (or data plane), and
routing performance (or control plane). In practice, the two functions are often evaluated simultaneously.
To test forwarding performance, IP load testers typically surround a router with simulated
Internet traffic. This function is called ''packet blasting'', and there are a couple of popular methods. The first method approximates real Internet traffic by using a representative mix of packet lengths, usually referred to as
IMIX. Another popular technique is to blast the router with the shortest packet lengths possible, in order to stress the computational performance of the router. In both cases, the IP load tester measures the performance of the router in terms of
loss,
latency and
throughput.
To test the control plane, IP load testers typically emulate various
protocols via the test ports in order to connect to the real implementations of those protocols on the router itself. For example, within the core of the Internet, various
routing protocols
A routing protocol specifies how routers communicate with each other to distribute information that enables them to select routes between nodes on a computer network. Routers perform the traffic directing functions on the Internet; data packets ...
are used for the control plane, or routing function of routers. Core routing protocols include
BGP
Border Gateway Protocol (BGP) is a standardized exterior gateway protocol designed to exchange routing and reachability information among autonomous system (Internet), autonomous systems (AS) on the Internet. BGP is classified as a path-vector ...
,
IS-IS,
OSPF, and
RIP
Rest in peace (RIP), a phrase from the Latin (), is sometimes used in traditional Christian services and prayers, such as in the Catholic, Lutheran, Anglican, and Methodist denominations, to wish the soul of a decedent eternal rest and peace.
...
. Control plane performance is usually characterized by measurements of
scalability and performance. Scalability typically means how many protocol sessions can be handled by the router at one time, and ultimately is a stress of memory. Performance usually refers to a time-varying parameter, such as
sessions
Sessions may refer to:
* Sessions (surname), a surname
* Sessions (clothing company), an American apparel company
* Sessions Clock Company, an American clock manufacturer in the early 20th century
Arts, entertainment, and media
* ''The Sessions' ...
per second, and ultimately is a stress of CPU power.
Electronic test equipment
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