There has been a couple of changes introduced in this last phase to cater for the demand of network performance measurements.
Throughout the week, I've made a few changes to the VLAN design and what sort of traffic type is allowed through the VPN Tunnel and which has to go through the normal MPLS Cloud.
The main idea was to send atleast 2 other traffic types apart from voice, across the GRE Tunnel interface so that we can compare the Voice latency, jitter and delay during the traffic transmission.
From the last update, the call transmission were successfully made from one network to another and tracing the path that the voice packets traverse, it was confirmed that it is running through the tunnel. Even so, with the calls be made, one can clearly identify and hear a tiny delay and voice reverb through the process of making calls which defines the voice quality expected to be giving such performance without any QoS (quality of service) configured.
Choosing Quality of Service took quite abit of days to cover since I have very little knowledge of implementing them in any network apart from a basic Lab that was available on net. Therefore, with my Supervisor's suggestion, I've managed to pick out and implement a certain QoS but wasn't sure what it would do to the network. Further discussions were made with my supervisor and after a day of reading, I've managed to implement Priority Queuing QoS. The basic idea behind priority queuing is that it classifies certain packet types that is defined to be of either in one of the 4 major packet classifications. The major classes are as follows - High, Medium, Normal and Low and one can determine what class of traffic would they want their traffic to be tagged on. Priority Queuing gives the highest priority to those packets classed "High" and then it drops down accordingly as per mentioned above. Every other traffic is treated according to it's class and if there are no High class traffic available, medium class traffic gets the highest priority.
Network Performance measurements was my next phase and that became a challenge for i have scarcely any knowledge on Traffic Generation Router (TrafGen/TGN) or Network Quality Review (NQR). After a fair bit of reading, i was able to atleast understand the core basics of how it works. Basically, TrafGen sends out a packet from one interface, gets routed through the network and then back to the TrafGen router on another interface. With the round-trip performance of the traffic generated, one will then use NQR to measure the network performance, delay-stats, jitter-stats and the summary stats of each measured packet type that was generated. We can configure and choose the type of packet that we need to measure upon traffic generation and the application port number (layer 4) that acquires network performance review. NQR also can generate its own traffic and that also was taken into account.
Evidently, when configuring Traffic generation, any other traffic types can be running simultaneously but will not be measured with the simulated generated traffic from Traffic Gen or NQR but somehow i've managed to squeeze the performance for both simulated traffic (passive and active traffic) by reducing the packet sizes but increasing the packet transmission frequency. This method causes huge delay and variation in Voice network performance which will be discussed further in the final report of this project.
List below are some traffic generation/network performance tests performed today:
Without QoS
- Run NQR
- Run NQR and TrafGen
- Run NQR and TrafGen + ping packets end to and and make a call end to end
With QoS configured in the Network:
- Run NQR
- Run NQR and TrafGen
- Run NQR and TrafGen + ping packets end to and and make a call end to end
- Measure IP SLA ( No Load)
- Measure IP SLA (With Network Load: ping packets, calls end to end_
- Measure IP SLA + Load TrafGen and NQR Traffic
Finally, the last stage/phase from here is just to implement basic security features that was left to the very last stage so as to simplify network configurations.