METRODATA NetTESTER FAMILY USER MANUAL
76-02-107 Rev.A
Page 44 of 133
10 SERVICE ACTIVATION TESTING
Service Activation Testing is the term used to describe testing of a service prior to it
carrying any live traffic. Simulated traffic is generated and used to measure aspects
of the service performance. This can then be compared to the Service Level
Agreement (SLA), to provide confidence that this will be met in the live environment,
or to give advance warning of potential problems.
10.1 The Service Assurance Module
The Service Assurance Module (SAM) is a hardware block within the unit that
provides a flexible, multi-stream traffic generator and analyser, a loopback function
with Layer 2, 3 and 4 address-swapping, and a high resolution packet timestamping
system, all operating at Gigabit (NT1003 and NT005) or 10-Gigabit (NT10G05) wire-
speed.
The SAM is designed specifically for service activation testing. It is intended to be
used in a configuration where two units are connected via the service to be tested.
One unit generates traffic and sends it over the connection. The other unit performs
a loopback function, returning the traffic over the connection with addressing
information within each packet reversed. The first unit analyses the returning traffic,
extracting performance information which is processed and presented as required.
To this end, the SAM can be set to perform one of two basic functions, termed
Tester and Loopback.
Other configurations are not precluded. For example: a unit performing the loopback
function may operate with a third-party tester; or a unit performing the tester function
may work with a physical loopback that does not perform packet address
manipulation.
Note
: When the unit is restarted, it always reverts to the Loopback function.
10.2 Loopback Function
Loopback can operate in 3 modes: 'Layer 2', 'Layer 3' and 'Layer 4'.
The default mode is Layer 2.
10.2.1
Layer 2 Loopback
In a Layer 2 loopback, the unit will loop packets dependent on their destination MAC
address and the port on which they are received.
Destination MAC
Receive Port
00:C0:81:FF:00:00**
WAN
00:C0:81:8x.xx.xx*
WAN
00:C0:81:FF:00:01**
Any User
