3Com 4800G Series, Configuration Manual

Page: 1048 / 1246

1048 C
HAPTER
86: NQA C
ONFIGURATION
In an NQA test, the client sends different types of test packets to the peer to
detect the availability and the response time of the peer, helping you know
protocol availability and network performance based on the test results.
Supporting the collaboration function
Collaboration is implemented by establishing collaboration entries to monitor the
detection results of the current test group. If the number of consecutive probe
failures reaches a certain limit, NQA’s collaboration with other modules is
triggered. The implementation of collaboration is shown in Figure 307.
Figure 307 Implementation of collaboration
The collaboration here involves three parts: the application modules, the Track
module, and the detection modules.
■
The detection modules monitor the link status, network performance and so
on, and inform the Track module of the detection result.
■
Upon receiving the detection result, the Track module changes the status of the
Track object accordingly and informs the application modules. The Track
module works between the application modules and the detection modules
and is mainly used to obscure the difference of various detection modules to
provide a unified interface for application modules.
■
The application modules then deal with the changes accordingly based on the
status of the Track object, and thus collaboration is implemented.
Take static routing as an example. You have configured a static route with the next
hop 192.168.0.88. If 192.168.0.88 is reachable, the static route is valid; if
192.168.0.88 is unreachable, the static route is invalid. With the collaboration
between NQA, Track module and application modules, real time monitoring of
reachability of the static route can be implemented:
1 Monitor reachability of the destination 192.168.0.88 through NQA.
2 If 192.168.0.88 is detected to be unreachable, NQA will inform the static routing
module through Track module.
3 The static routing module then can know that the static route is invalid.
n
For the detailed description of the Track module, refer to “Configuring Track-NQA
Collaboration” on page 1238.
Track
module
Policy routing
Static routing
Backup center
VRRP
Detection
modules
NQA
Track
module
Application modules
Policy routing
Static routing
Backup center
VRRP
Detection
modules
NQA
BFD