Network KPI tests

The network KPI test described in this section will allow to test the network by sending "heatbeats" from node to node. These tests are especially suited for Mesh testing as they have little impact on the network and help understanding key transport metrics such as:

  • loss
  • jitter
  • delay

Packet loss is the percentage of packets that are lost out of all packets transmitted. Packet loss burst is a count of the largest number of consecutive packets lost. Important to note that even a small percentage of packets lost can cause TCP packet retransmissions which can lead to network congestion and apparently slow down the network.

These are key SLA indicator for network health and Service Level Agreements.

  Network KPI from->to
Description

Test network delivery KPI with low foot print (100kbps) and 50 packets per second- From E1 to E2 direction.

Purpose

Measuring key KPI loss/jitter/latency.

Available Options

DSCP setting.

Metrics
  • One way delay (ms)
  • jitter (ms)
  • max jitter (ms)
  • packet loss (%)
  • voice MOS score
  • packet loss burst
  • Max delay variation(ms)
Advanced Information

This test will generate unidirectional  traffic with heartbeats to measure the key metrics. The traffic is similar to voice traffic - MOS score is an indicator of capacity of the link to transport Voice in a good quality.

The following definitions help to understand key metrics:

  • Max delay variation: The time from when a packet is sent from a probe to when it is received, end to end, is the delay. The max delay variation is the difference between the shortest time and the longest time for this end to end delay for exchanging packets.
  • Max jitter: This measures the variance in spacing between packets sent end to end. If the difference in time (spacing) between 1st and 2nd packet send from first probe is 2ms, and the time on far end probe receiving 1st and 2nd packets is 3.7ms, the jitter is 3.7ms - 2ms = 1.7ms.
Results interpretation

The network KPI pair generates packets RTP stream.

These packets traverse the network from one probe to the other and provides indication based on time sent and receive, how many are lost etc...

The packets are sent similarly to a G711 voice stream as this is expected to be a key application the network shall be able to transport.

Voice MOS score gives an indication of the quality of transport network for voice G711 application.

Potential

Errors

If test result pair cannot be collected:

  • Check that your E2 endpoint can open 10115 port toward E1 for management (this is needed for stream pairs).
  • Check that synchronization port between pairs is opened (management UDP 10115).
  • Check that port in use is in range (see "preferences/Test Controller/Destination Port Conf Option" and "preferences/Test Controller/First Destination Port" so that correct destination port for test traffic is used.

 

  Network KPI from->to 3 COS
Description

Test network delivery KPI with low foot print (100kbps per COS) and 50 packets per second- From E1 to E2 direction, on 3 different COS.

Purpose

Measuring key KPI loss/jitter/latency for 3 COS.

Available Options

Per COS :

  • DSCP setting
Metrics

Per COS:

  • one way delay (ms)
  • jitter (ms)
  • max jitter (ms)
  • packet loss (%)
  • voice MOS score
  • packet loss burst
  • max delay variation(ms)
Advanced Information

This test will generate unidirectional  traffic with heartbeats to measure the key metrics. The traffic is similar to voice traffic - MOS score is an indicator of capacity of the link to transport Voice in a good quality.

Results interpretation

The network KPI pair generates packets RTP stream.

These packets traverse the network from one probe to the other and provides indication based on time sent and receive, how many are lost etc...

The packets are sent similarly to a G711 voice stream as this is expected to be a key application the network shall be able to transport.

Voice MOS score gives an indication of the quality of transport network for voice G711 application.

Potential

Errors

If test result pair cannot be collected:

  • Check that your E2 endpoint can open 10115 port toward E1 for management (this is needed for stream pairs).
  • Check that synchronization port between pairs is opened (management UDP 10115).
  • Check that port in use is in range (see "preferences/Test Controller/Destination Port Conf Option" and "preferences/Test Controller/First Destination Port" so that correct destination port for test traffic is used.

 

  Network KPI to->from
Description

Test network delivery KPI with low foot print (100kbps) and 50 packets per second- From E2 to E1 direction.

Purpose

Measuring key KPI loss/jitter/latency.

Available Options

DSCP setting.

Metrics
  • One way delay (ms)
  • jitter (ms)
  • max jitter (ms)
  • packet loss (%)
  • voice MOS score
  • packet loss burst
  • max delay variation(ms)
Advanced Information

This test will generate unidirectional  traffic with heartbeats to measure the key metrics. The traffic is similar to voice traffic - MOS score is an indicator of capacity of the link to transport Voice in a good quality.

Results interpretation

The network KPI pair generates packets RTP stream.

These packets traverse the network from one probe to the other and provides indication based on time sent and receive, how many are lost etc...

The packets are sent similarly to a G711 voice stream as this is expected to be a key application the network shall be able to transport.

Voice MOS score gives an indication of the quality of transport network for voice G711 application.

Potential

Errors

If test result pair cannot be collected:

  • Check that your E2 endpoint can open 10115 port toward E1 for management (this is needed for stream pairs).
  • Check that synchronization port between pairs is opened (management UDP 10115).
  • Check that port in use is in range (see "preferences/Test Controller/Destination Port Conf Option" and "preferences/Test Controller/First Destination Port" so that correct destination port for test traffic is used.

 

  Network KPI bidirectional
Description

Test network delivery KPI with low foot print (100kbps) and 50 packets per second- From E1 to E2 direction and E2 to E1 simultaneously.

Purpose

Measuring key KPI loss/jitter/latency.

Available Options

DSCP setting.

Metrics

Per direction:

  • One way delay (ms)
  • jitter (ms)
  • max jitter (ms)
  • packet loss (%)
  • voice MOS score
  • packet loss burst
  • max delay variation(ms)
Advanced Information

This test will generate unidirectional  traffic with heartbeats to measure the key metrics. The traffic is similar to voice traffic - MOS score is an indicator of capacity of the link to transport Voice in a good quality.

Results interpretation

The network KPI pair generates packets RTP stream.

These packets traverse the network from one probe to the other and provides indication based on time sent and receive, how many are lost etc...

The packets are sent similarly to a G711 voice stream as this is expected to be a key application the network shall be able to transport.

Voice MOS score gives an indication of the quality of transport network for voice G711 application.

Potential

Errors

If test result pair cannot be collected:

  • Check that your E2 endpoint can open 10115 port toward E1 for management (this is needed for stream pairs).
  • Check that synchronization port between pairs is opened (management UDP 10115).
  • Check that port in use is in range (see "preferences/Test Controller/Destination Port Conf Option" and "preferences/Test Controller/First Destination Port" so that correct destination port for test traffic is used.

 

  Network KPI Low Bandwidth
Description

Test network delivery KPI with advanced parameters for packet settings - From E1 to E2 direction - with very low bandwidth (<2kbps line rate) . Only sends 1 hearbeat per second (lower precision).

Purpose

Measuring key KPI loss/jitter/latency.

Available Options
  • Total bitrate (kbps) for the stream
  • DSCP setting
  • packet size
Metrics
  • One way delay (ms)
  • jitter (ms)
  • max jitter (ms)
  • packet loss (%)
  • packet loss burst
  • max delay variation(ms)
Advanced Information

This test will generate unidirectional  traffic with heartbeats to measure the key metrics. the low bandwidth of measurements make them less precise than the standard network KPI tests.

Results interpretation

The network KPI pair generates packets RTP stream .

These packets traverse the network from one probe to the other and provides indication based on time sent and receive, how many are lost etc...

Potential

Errors

If test result pair cannot be collected:

  • Check that your E2 endpoint can open 10115 port toward E1 for management (this is needed for stream pairs).
  • Check that synchronization port between pairs is opened (management UDP 10115).
  • Check that port in use is in range (see "preferences/Test Controller/Destination Port Conf Option" and "preferences/Test Controller/First Destination Port" so that correct destination port for test traffic is used.

 

  Network KPI advanced
Description

Test network delivery KPI with advanced parameters for packet settings - From E1 to E2 direction.

Purpose

Measuring key KPI loss/jitter/latency.

Available Options
  • Total bitrate (kbps) for the stream
  • DSCP setting
  • packet size
Metrics
  • One way delay (ms)
  • jitter (ms)
  • max jitter (ms)
  • packet loss (%)
  • packet loss burst
  • max delay variation(ms)
Advanced Information

This test will generate unidirectional  traffic with heartbeats to measure the key metrics.

Results interpretation

The network KPI pair generates packets RTP stream .

These packets traverse the network from one probe to the other and provides indication based on time sent and receive, how many are lost etc.

Potential

Errors

If test result pair cannot be collected:

  • Check that your E2 endpoint can open 10115 port toward E1 for management (this is needed for stream pairs).
  • Check that synchronization port between pairs is opened (management UDP 10115).
  • Check that port in use is in range (see "preferences/Test Controller/Destination Port Conf Option" and "preferences/Test Controller/First Destination Port" so that correct destination port for test traffic is used.
  • RTP packet loss may be seen above 7 Mbps with default packet size of 50 bytes. In this case, we recommended you to increase packet size to 500 or 1400 bytes. This particularly can be encountered on the XRPi.

The XRPi will encounter performance issues of increased packet loss for throughput above 8Mbps using a packet size of 50 bytes. Using a larger RTP packet size of 500 or 1400 bytes will result in fewer packets processed and lost.