Atec EXFO-FTB-8510G - Manual (Page 3)

Ethernet Performance Validation
FTB-8510G
10 Gigabit Ethernet Test Module
Metro Network
Gigabit Ethernet
10/100Base-T 10/100Base-T
Internet
Gigabit Ethernet
10 GigE
10 GigE
Testing can be performed end-to-end or end-to-core, depending
on the SLA. Remote testing is also possible.
Rx
Local Remote
Metro network
Tx
Tx
Rx
Example of throughput test application.
The Internet Engineering Task Force (IETF) has put together a test methodology to address the issues of performance verification at the
layer 2 and 3 level. RFC 2544, a “Benchmarking Methodology for Network Interconnect Devices,” specifies the requirements and
procedures for testing throughput (performance availability), back-to-back frames (link burstability), frame loss (service integrity) and
latency (transmission delay).
When these measurements are performed, they provide a baseline for service providers to define SLAs with their customers. They enable
service providers to validate the quality of service (QoS) delivered and can provide them with a tool to create value-added services that
can be measured and demonstrated to customers. For example, these tests provide performance statistics and commissioning
verification for virtual LANs (VLANs), virtual private networks (VPNs) and transparent LAN services (TLS), all of which use Ethernet as
an access technology.
The SLA criteria defined in RFC 2544 can be precisely measured using specialized test instruments. The performance verification
is usually done when the installation is completed. The measurements are done out-of-service to make sure that all parameters
are controlled.
RFC 2544 TEST SUITE
The following sections describe each of the RFC 2544 tests. The test
equipment used should be able to generate and analyze traffic for
10GBASE-xR or 10GBASE-xW full duplex networks at all frame sizes in
order to test transparent connectivity for LAN-to-LAN services delivered via
Next-Generation SONET/SDH, SONET/SDH hybrid multiplexers, switched
Ethernet, VLANs, dark fiber, WDM or other means. The instruments should
be capable of transmitting at full line rate, in order to allow the provider to
certify that the circuit is efficient and error-free at 100% utilization.
Some test instruments allow automated testing, which helps to ensure
repeatable results. Automation also provides ease of use for technicians in the
field by enabling accurate, efficient measurements and providing reports they
can give to customers for future reference related to their specific SLAs.
THROUGHPUT
Throughput is the maximum rate at which none of the offered frames are
dropped by the device under test (DUT) or network under test (NUT).
For example, the throughput test can be used to measure the rate-limiting
capability of a switch. The throughput is essentially equivalent to the
bandwidth.
The throughput test allows vendors to report a single value which has
proven to be useful in the marketplace. Since even the loss of one frame in
a data stream can cause significant delays while waiting for the higher level
protocols to time out, it is useful to know the actual maximum data rate that
the device can support. Measurements should be taken over an assortment
of frame sizes. Separate measurements should be made for routed and
bridged data in those devices that can support both. If there is a checksum
in the received frame, full checksum processing should be done.
Throughput test procedure:
1. Send a specific number of frames at a specific rate through the DUT/NUT
and then count the frames that are transmitted by the DUT/NUT.
2. If the count of offered frames is equal to the count of received frames, the rate
of the offered stream is raised and the test rerun.
3. If fewer frames are received than were transmitted, the rate of the offered stream
is reduced and the test is rerun.
4. The throughput is the fastest rate at which the count of test frames transmitted
by the DUT/NUT is equal to the number of test frames sent to it by the test equipment.