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Next, according to the previous parameters the execution jumps to the code section
that involves only the current session. If, for example the current session is a session
of traffic analysis using the DAG, the session running function, after determining
these parameters, is focused only on executing the pieces of program dedicated to that
scenario.
Notes
The Session Manager uses a series of codes for describing each type of session. There
are seven codes in total describing five possible session scenarios. Each scenario is
implemented separately on both the start and running function. In figure 3.50, you can
identify each scenario by looking at the bolded text, which means different
negotiation management message for each of the five.
Table 3.37 contains a description of each session type mapped to each session
scenario.
Table 3.37 Mapping session types and hardware to session scenarios
Session Type
Code
Hardware Used
Generating Layer 2 (Ethernet)
0
Regular NIC
Generating Layer 3 (IP)
1
Regular NIC
Generating Layer 4 (UDP)
2
Regular NIC
Analysis
3
Generating and Analysis Layer 2
4
Generating and Analysis Layer 3
5
Generating and Analysis Layer 4
6
Session Scenario
Traffic Generation
Regular NIC
Traffic Analysis using Ethernet
Endace DAG
Traffic Analysis using DAG
Regular NIC
Traffic Generation and Analysis using
Ethernet
Endace DAG
Traffic Generation and Analysis using
DAG
After the determination of the session scenario, the program checks the flow step of the task.
According to the numeric value of this parameter, the execution jumps to a particular subprocedure that is executed. During this procedure, the decision is also taken if at the next
moment the step remains the same, it is changed, or even the task is finished.
It is not the intention of this document to explain the execution flow for each session scenario.
You must understand only the principle of execution, since the only difference between the
scenarios is only that at the same step indexes other operations are performed, operations that
imply:
Creating management messages using the SNMP wrapper (the messages are
automatically added to the outbound queue)
Testing the inbound queue for replies
Retrieving the replies from the inbound queue
Using the SNMP wrapper to extract QoS data from the SNMP variables
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