【 Weak current College 】 router testing technology introduction and test types and methods

The router forwards the packets by for network interconnect devices can support more than one Protocol (e.g. TCP/IP, IPX/SPX, AppleTalk), multiple levels of forwarding packets (such as data-link layer, network layer and application layer).

1. purpose and content of the test

The router forwards the packets by for network interconnect devices can support more than one Protocol (e.g. TCP/IP, IPX/SPX, AppleTalk), multiple levels of forwarding packets (such as data-link layer, network layer and application layer).

Router you need to connect two or more logical port, at least one physical ports. Router based on the received packet network layer address of the router routing table maintained internally determines the output ports as well as the next router address or host address, and rewrite the link-layer header. Routing tables must be dynamic maintenance to reflect the current network topology. Routers usually by and other routers exchanging routing information to complete the dynamic maintenance of the routing table.

(A) the router category

The current router classification methods vary. Various classifications to be associated, but not entirely consistent. Usually you can follow the router capability classification, structure, classification, network location, classification, function classification and performance categories. In router standard classification according to capacity in the main, the capacity is divided into high-end router and low-end routers. Backplane switching capacity greater than 20Gbit/s, the throughput is greater than 20Mbit/s router called the high-end router. Exchange capacity in these data the following routers become low-end routers. And this corresponds to router test code into high-end test specification for low-end router test code and.

(Ii) for testing purposes and content

By testing the router, you can learn what routers are able to provide the best performance, the router in different load behavior, model-based design of the network using a router, the router can handle parameters of unexpected traffic, router performance limitations, routers can provide a different quality of service, the router different architecture for functionality and performance impacts, router features and performance indicators, the effects of using a router is a network security, router protocol implementation conformance, and router reliability and router products strengths and weaknesses.

Low-end router device test mainly include: the General test, i.e. electrical safety testing; environmental testing, including high and low temperature, humidity and high temperature storage test; physical interface testing, test low-end routers might have the electrical and physical interface Testability; Protocol conformance test, the test protocol implementation conformance; performance testing, test the performance of the router; manage tests, test a router-to-no major network management function.

High-end router tests include: interface test, high-end router may have interface test; ATM protocol testing, test the ATM protocol requirements PP protocol testing, test the consistency of the PPP protocols; IP protocol testing, test IP protocol conformance; routing protocol test, the test route conformance; network management function test, verify that the test gateway functionality; performance and QoS router performance testing, test and validate QoS capabilities; network synchronization testing, test device synchronization timing capabilities; reliability tests to verify the device reliability; power supply test, the test machine power consumption, and other content; environmental testing, including high and low temperature, humidity and high temperature storage test.

These two test code as drafting unit, as well as the drafting of the time, the organization is different. In addition to the above tests, it is recommended that you test in considering the test items listed below. (1) functional testing: mainly to verify product availability of the design of every feature. (2) the stability and reliability of the test: take a heavier load on the general approach to the assessment and analysis equipment for a long time, high load capacity of the run. (3) interoperability test: different network between products must be able to interoperate. Interoperability testing on a network product be in a variety of different manufacturers of network products interconnected network environment to work in, for example, verify that the routers and Cisco product interoperability, switches and Cisco, Lucent, 3Com, Intel, interoperability, etc.

2. test method

Router test method is typically divided into local test method, the distribution of the test method, remote test method and the collaborative test method. Because of space limitations, this article does not describe the characteristics of other test method and the scope of application, list only the most commonly used in testing the router to the remote test method.

Among them, the control of the observation point (PCO): usually consists of two first-in first-out (FIFO) queue, its function is similar to a pair of input and output ports, and send a command to the end of the queue, from the other end of the same queue receive answer signal; the measured entity (IUT): ItemUnderTest; next Tester (LT): located in the tested entity underlying PCO and the test layer interaction test system known as the lower test system.

III. testing category

Integrated in the test above, router tests generally can be divided into the following categories: functional testing, performance testing, stability and reliability testing, conformance testing, interoperability testing, and network testing.

(A) functional testing

Router functions can often be divided into the following areas.

(1) interface function: this function used as a router to connect to the network. Can be divided into the LAN interface and wide area network interface. LAN interfaces including Ethernet, token ring, FDDI, token ring, bus, and other network interfaces. WAN interfaces including E1/T1, T3, E3/DS3, generic serial interface (convertible into X.21DTE/DCE, V.35DTE/DCE, RS232DTE/DCE, RS449DTE/DCE, EIA530DTE) network interface. (2) communication protocol function: the function responsible for handling communication protocols, including TCP/IP, PPP, X.25, frame relay, etc. (3) packet forwarding: this feature is mainly responsible for the content according to the routing table in the port (including logical port) to forward packets between and overwrites a link-layer header information. (4) routing information maintenance function: this function is responsible for running the routing protocols to maintain the routing table. RIP routing agreement may include, OSPF, BGP, and other protocols. (5) management control functions: router management control features include five functional, SNMP agent feature, Telnet Server features, local management, remote monitoring and RMON function. There are several different ways to control the management of the router, and allow the record to the log. (6) security features: for complete packet filtering, address translation, access control, data encryption, firewalls, address assignment, and other functions.

The router is not necessary for the above functionality is fully realized. But because the router exists as a network device, the minimum set of features, the feature set to the minimum required functionality, the router must support. Because the vast majority of functional tests can be interface testing, performance testing, Protocol conformance test and network management tests cover, so the router function testing in General can only on other test cannot cover features for confirmatory testing. Router functionality testing generally use remote test method.

(Ii) performance testing

The router is the IP network core equipment, which have a direct impact on the performance of IP networks network size, network stability and network scalability. Because the IETF does not have the router performance testing for special provisions, in General can only follow RFC2544 (BenchmarkingMethodologyforNetworkInterconnectDevices) for testing. But the router is distinguished from ordinary simple network interconnect devices, performance testing should also be coupled with the router's unique performance testing. For example routing table size, routing protocols, such as the convergence time.

Router performance tests shall include the following indicators.

(1) throughput: testing the router packet forwarding. Usually a router without packet loss conditions forwarded packets per second, the limit is generally can find the ultimate point of dichotomy. (2) the delay: testing the router in throughput range from the receipt of the package to forward a package of time intervals. Delay test should be repeated 20 times and then take the average. (3) the packet loss rate: testing the router discards the packet under different load account receives a proportion of the package. From different load usually refers to the wire-speed throughput test (line transmission package highest rate), the step size generally use wire-speed 10%. (4) back-to-back frames: testing the router receives the minimum package interval transit packet loss condition can handle the maximum number of packages. The actual test router caching, if the router is equipped with wire-speed capabilities (throughput = interface media wire-speed), this test does not make sense. (5) system recovery time: testing the router in resuming normal work after overload. Test methods can be used to send a router port throughput of 110% and linear speed of the smaller value, 60 seconds after the rate drops to 50% of the moment to the last packet intervals. If the router is equipped with wire-speed, the test does not make sense. (6) the system reset: testing the router from software reset or off electrical reset to normal working time interval. Normally refers to forward data throughput.

In the test above RFC2544 in indicators should take into account the following factors.

Frame format: it is recommended that you follow the RFC2544 frame format test; frames long: from the smallest frame length to MTU sequentially incremented, such as Ethernet with 64, 128, 256, 512, 1024, 1280, 1518 bytes; certification receives frames: exclude received non-test frame, such as control of frame, frame, etc. routing updates; broadcast frames: Verify broadcast frames on the performance of the router, the above tests in the test frame in 1% of the broadcast frames and then testing; management frame: authentication management frame to router performance, the above tests in the test frame inclusion in a management frames per second and then testing; routing update: routing updates that next jump port change effect on performance; filter: filter condition on the performance of the router, it is recommended that you set 25 filter condition test; protocol address: testing the router to receive random is 256 network address performance impact; the bi-directional flow: testing the router port bidirectional transceiver data performance impact; multiport test: considering the flow distribution across the connection or non-whole connection distribution performance impact; multi-protocol testing: consider the router at the same time to handle multiple protocols, performance impact; mixed bag long: in addition to testing the proposed incremental package long, check for mixed packet length on the performance of the router, RFC2544 requires contains all the test package has no longer on the hybrid packet length in the proportion of the package for long. The author recommends in accordance with the actual network in each package long distribution test, for example, in the absence of special application requirements for Ethernet interface can adopt 60 byte packet of 50%, 128-byte packet 10%, 15% of the 256 byte packet, 512-byte packet 10%, 15% 1500 byte packet. In addition to the above recommendation of test entry RFC2544 also recommends test follows.

① Routing shocks: routing shocks on router forwarding capacity. The extent to which the route shocks per second update routing number based on network conditions. Routing update protocol can use BGP. ② routing table size: the size of the test routing table. Backbone routers typically run BGP routing table contains routes worldwide. Generally require more than 10 million records routing, it is recommended that you enter by using BGP to test the export route count. ③ clock synchronization: contains the corresponding ports such as POS-routerWithin the clock accuracy on test and synchronization capabilities. ④ Protocol convergence time: test routing change notification to the time of the whole network. The index while the stand-alone performance for the router, but generally can only test on the network, and will vary by configuration changes. You can configure in network is completed by examining the indicators to measure the overall network performance. Test time should be according to the specific project and the test target. Generally considered that the test time should be between 60 to 300 seconds. In addition to General can according to user requirements and test target for setting options. Router performance tests generally take remote test method.

(Iii) the conformance test

Router conformance testing usually uses the "black box" method, tested device IUT is called "black box". Test the system by controlling the observation point of the PCO and the tested device interface.

Different test events through different PCO to control and observation, and follow the answer whether compliance with norms, namely timing relationships and data matching, test results can be passed, failed, no results 3. A router is a complex network interconnect devices, various communication layers on a variety of protocols. For example, the interface of the physical layer and link layer protocols, IP/ICMP, and other Internet layer protocol, TCP/UDP transport layer protocol, such as Telnet/application layer protocols such as SNMP and RIP/OSPF/BGP and other routing protocols.

Protocol conformance testing should include all of the implementation of the router. As a result of the test content variety testing complex, in tests can select important agreements and are concerned about content testing. As the backbone of the Internet road there may affect global routing, so router tests should pay special attention to the routing protocol conformance test such as OSPF and BGP protocol. As a result of conformance testing can only choose a limited test cases to test, generally does not cover all the contents of the agreement. So even if the test is also no guarantee that the device fully achieved agreement all content, so the best way is in a real-world environment. Router conformance testing generally use distributed test method or remote test method.

(Iv) interoperability test

As communication protocol, routing protocols, is complex and has many options to achieve the same protocol router does not guarantee interoperability Interop. And because conformance testing capabilities are limited, even through Protocol conformance test may not be able to guarantee the full implementation of the agreement. Therefore it is necessary for interoperability testing equipment.

Interop test is actually testing the consistency in the instrument needs to be replaced by the exchange of interoperable equipment, select some important and typical interconnection configuration, observation of two devices can works as expected.

(V) the stability and reliability testing

Since most routers need 24 hours a day, 7 days a week, as the backbone of the Internet's core router device stability and reliability are particularly important. So users need to understand the dew from the stability and reliability.

The router's stability and reliability are hard to test. Generally two ways: (1) manufacturers through key parts of the degree of reliability and backup system reliability; (2) the user or by a large number of identical products manufacturers in the use of failure rate statistics product stability and reliability. Of course, may also be accessed at one time, the results of running the test require to guarantee the reliability and stability of the router.

(Vi) network management tests

Network Management test generic test network management software on the network, and network device management capability. Because the router is the IP network core equipment, so you must test the routers on the network management support. If a router with network management software, you can use the attached network management software to check for network management software implementation of configuration management, security management, performance management, billing management, fault management, topology management and view management functions. If the router does not come with network management software, you should test the router on the consistency of the SNMP protocol implementation and realization of the MIB. Because the router needs to implement many of the MIB, each MIB contains large amounts of content, it is difficult to completely test the MIB. Generally available through sampling important to check the router MIB entry on an implementation of the MIB.