Atec EXFO-FTB-8510G - Manual (Page 5)

FTB-8510G
10 Gigabit Ethernet Test Module
BERT OVER ETHERNET
Because transparent transport of Ethernet over physical media is becoming a
common service, Ethernet is increasingly carried across a variety of layer 1 media
over longer distances. There is therefore a growing need to certify Ethernet transport
on a bit-per-bit basis. This can be done using bit-error-rate testing (BERT).
BERT uses a pseudo-random binary sequence (PRBS) encapsulated into an
Ethernet frame, making it possible to go from a frame-based error measurement
to a bit-error-rate measurement. This provides the bit-per-bit error count accuracy
required for the acceptance testing of physical-medium transport systems.
BERT over Ethernet should be used when Ethernet is carried transparently over
layer 1 media, in cases such as:
Ethernet-over-DWDM
Ethernet-over-CWDM
Ethernet-over-dark fiber
FRAME ANALYSIS
This FTB-8510G Packet Blazer feature enables multistream traffic generation
and analysis allowing for the troubleshooting of Ethernet circuits as well as
customer-traffic analysis and error identification. Thanks to its packet jitter
measurement capability (RFC 3393), the FTB-8510G lets service providers
efficiently benchmark transport networks when it comes to delay-sensitive traffic
such as voice-over-IP (VoIP).
SMART LOOPBACK
This feature allows transmitting back the received stream of data.
To perform an end-to-end frame analysis, BERT or RFC 2544
across a layer 2, traffic needs to be looped back to the originator.
A remote unit running the Smart Loopback mode will allow traffic
to be returned to the local unit by swapping packet overhead up
to layer 4.
ETHERNET SERVICE ACCEPTANCE TESTING
The type of testing required for Ethernet service acceptance
testing depends on how the service is carried on the network.
The opposite figure shows how to test for switched transport
or transparent physical transport using either RFC 2544 tests or
BERT-over-Ethernet.
All of the tests that are part of the service-level agreement can be
performed on either part of the network (end-to-core) or on all of it
(end-to-end). For both switched transport and transparent physical
transport, end-to-end testing can be performed by using two
portable units and testing from one end to the other. Another way
of doing this is to send a technician to one site and test using
a second test device that is mounted in the network (e.g., in a
central office). This type of testing is useful when two technicians
cannot be sent at the same time or when the service provider is
providing access to the Internet.
Service accepted
Switch transport Transparent physical transport
RFC 2544 Packet jitter BERT
Are SLA performance
parameters met?
Is media 100% error free?
Yes No No Yes
Service rejected
Is the Ethernet service delivered via switched
transport or via transparent physical transport?
TX
RX
Metro Network
Example of EtherBERT Configuration.
Metro
Network
Example of Smart Loopback test application.