IP Load tester
Encyclopedia
IP load testers are a class of protocol analyzer
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 are used for the control plane, or routing function of routers. Core routing protocols include BGP, IS-IS
, OSPF, and RIP
. 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
per second, and ultimately is a stress of CPU power.
Protocol analyzer
A "Protocol analyzer" is a tool used to capture and analyze signals and data traffic over a communication channel. Such a channel differs from a local computer bus to a satellite link, that provides a means of communication using a standard communication protocol...
s focused on the practical evaluation of router performance. Router performance is usually broken down into two categories: forwarding performance
Forwarding plane
In routing, the forwarding plane, sometimes called the data plane, defines the part of the router architecture that decides what to do with packets arriving on an inbound interface...
(or data plane), and routing performance
Routing Information Protocol
The Routing Information Protocol is a distance-vector routing protocol, which employs the hop count as a routing metric. RIP prevents routing loops by implementing a limit on the number of hops allowed in a path from the source to a destination. The maximum number of hops allowed for RIP is 15....
(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
Internet traffic
-Historical Internet Traffic Growth:Because of the distributed nature of the Internet, there is no single point of measurement for total 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
Packet loss
Packet loss occurs when one or more packets of data travelling across a computer network fail to reach their destination. Packet loss is distinguished as one of the three main error types encountered in digital communications; the other two being bit error and spurious packets caused due to noise.-...
, latency
Latency (engineering)
Latency is a measure of time delay experienced in a system, the precise definition of which depends on the system and the time being measured. Latencies may have different meaning in different contexts.-Packet-switched networks:...
and throughput
Throughput
In communication networks, such as Ethernet or packet radio, throughput or network throughput is the average rate of successful message delivery over a communication channel. This data may be delivered over a physical or logical link, or pass through a certain network node...
.
To test the control plane IP load testers typically emulate various protocols
Communications protocol
A communications protocol is a system of digital message formats and rules for exchanging those messages in or between computing systems and in telecommunications...
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 are used for the control plane, or routing function of routers. Core routing protocols include BGP, IS-IS
IS-IS
Intermediate System To Intermediate System , is a routing protocol designed to move information efficiently within a computer network, a group of physically connected computers or similar devices....
, OSPF, and RIP
Routing Information Protocol
The Routing Information Protocol is a distance-vector routing protocol, which employs the hop count as a routing metric. RIP prevents routing loops by implementing a limit on the number of hops allowed in a path from the source to a destination. The maximum number of hops allowed for RIP is 15....
. Control plane performance is usually characterized by measurements of scalability
Scalability
In electronics scalability is the ability of a system, network, or process, to handle growing amount of work in a graceful manner or its ability to be enlarged to accommodate that growth...
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
Session (computer science)
In computer science, in particular networking, a session is a semi-permanent interactive information interchange, also known as a dialogue, a conversation or a meeting, between two or more communicating devices, or between a computer and user . A session is set up or established at a certain point...
per second, and ultimately is a stress of CPU power.