problematización y propuesta
2.1 Los inmigrantes: ¿un grupo, una agrupación o una categoría? categoría?
Execute the Test
Map the ports and run the test.
Test Variables
Table 63.
Parameter Name Current Value Additional Options
IP Type IPv4 IPv6
Type of traffic Audio Video, T38, Audio/Video RTCP
IP Mapping rules for User agents N to 1 1 to 1, 1 to N, N to 1, and N to N Number of users available User defined
Number of active calls User defined
Call Rate User defined
Call Duration User defined
Audio CODEC (type, packet size &
frequency) G.711u
G.711a, G.729, G.723, G.726, iLBC, AMR, any other codec using Custom Codec
Mix with data protocols (for
example, FTP, HTTP, Telnet) Not included Any combination of data protocols supported by IxLoad
Mix of call flows successfully calls, canceled calls,
unanswered calls, busy calls
Mix of call features call forward, call transferred, call
hold/retrieve
Results Analysis
The DUT shall be monitored for the following:
Memory size, memory allocation/de-allocation issues while:
o Translations are added/deleted to/from the NAT table
o Translations are continuously added and sessions are kept active
CPU usage
Size of NAT table
The following questions provide guidelines on how to recognize specific problems during or at the end of the test execution:
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Table 64. Call Rate statistics
Statistic Name Value Questions
Calls Attempted per Second
1. Have the calls been attempted continuously at a constant call rate during the Sustain Time?
2. How do the Calls Attempted rate and the Calls Connected rate compare to each other?
Calls Connected per Second
2. Have any call failures been reported? Check the Calls view.
Table 65. Call statistics
Statistic Name Questions Calls Attempted
1. Have any call attempts failed?
Compare:
a. Calls Attempted and Calls Received, with b. Calls Attempted and Calls Connected.
Calls Connected Calls Received Calls Answered End Calls Received End Calls Completed
3. Have any scenario loop failures been reported? Check the Loops statistics view.
Table 66. Statistics highlighting the pass/fail result based on call flow execution
Statistic Name Questions
Total Loops 1. Are the Successful Loops and Total Loops values equal?
2. Have any Failed Loops, Aborted Loops or Warning Loops been reported?
Note: failed/aborted and warning loops highlights failures at the scenario level.
Successful Loops Failed Loops Aborted Loops Warning Loops
4. Have all messages received by cloud been dispatched correctly?
Table 67. Dispatched messages stats
Statistic Name Questions
Undispatched Messages under SIP Cloud view
1. Is any SIP message received and not dispatched?
Note: If there are Undispatched messages, the dispatching rules do not cover all the cases. The Dispatching Rules set on each activity should be checked; typically, the error is in mismatching of the phone numbers.
Figure 171. Dispatching SIP Messages Stats
5. Has the QoS for signaling met the expected quality? Check the Call Times and Delays statistic views. Use the maximum value reported.
Table 68. Statistics used to determine the QoS for the SIP signaling
Statistic Name Questions
Call Setup Time 1. Is the maximum Call Setup Time less than 4 seconds?
2. Is the maximum End Call Time less than 2 seconds?
3. Is the maximum Media Delay (Tx or Rx) less than 4 seconds?
4. Is the maximum Post Dial Delay less than 2 seconds?
5. Is the maximum Post Pickup Delay less than 2 seconds?
6. For all the stats listed in this table, compare their value distribution in time.
6. In some cases, the DUT is not involved in the media path. In other cases, for example, when the SIP User agents are in different networks, the DUT handles the media as well. In this case, the following quality of media indicators should be checked: RTP MOS RTP QoS, RTP Advanced QoS, RTP Jitter Distribution, RTP Consecutive Lost Datagram Distribution, and RTP Streams statistic views.
Table 69. MOS statistics
Statistic Name Questions RTP MOS Best
RTP MOS Worst
1. How do the last values reported by the RTP MOS Best and RTP MOS Worst compare with each other?
2. How does the RTP MOS Worst score compare with the max theoretical score for the CODEC used?
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RTP MOS Instant (Best/Avg/Worst)
3. Are any times without an instantaneous MOS value?
4. How frequent are the changes in the instantaneous MOS values?
RTP MOS Per Call (Best/Avg/Worst)
5. How do the MOS per Call statistics compare with the RTP MOS Best and RTP MOS Worst statistics?
Table 70. Basic RTP QoS statistics (see RTP QoS and RTP Advanced QoS statistics views)
Statistic Name Questions RTP Packets Sent
RTP Packets Received RTP Packets Lost
1. Are there any differences between RTP Packets Sent and RTP Packets Received?
2. Does the difference match the value of RTP Lost Packets?
RTP One Way Delay [us] 3. Is the One Way Delay higher than 100 ms?
RTP Delay Variation Jitter [us]
RTP Interarrival Jitter [us]
4. What is the max Delay Variation Jitter?
5. What is the max Interarrival Jitter?
Table 71. RTP Jitter distribution statistics
Statistic Name Questions Packets with Delay Variation Jitter up to 1 ms
1. Assuming Jitter was reported, what is the distribution of the Delay Variation Jitter values?
Packets with Delay Variation Jitter up to 3 ms
Packets with Delay Variation Jitter up to 5 ms
Packets with Delay Variation Jitter up to 10 ms
Packets with Delay Variation Jitter up to 20 ms
Packets with Delay Variation Jitter up to 40 ms
Packets with Delay Variation Jitter over 40 ms
Table 72.
Table 73. Distribution of RTP Consecutive Lost Packets
Statistic Name Questions
Consecutive Loss of One Packet Sequence
1. Assuming that packet loss was reported, what is the
distribution of the lost RTP packets?
Consecutive Loss of Two or Three Packet Sequences Consecutive Loss of Four or Five Packet Sequences Consecutive Loss of Six to Ten Packet Sequences Consecutive Loss of Eleven or More Packet Sequence
Table 74. RTP Streams
Statistic Name Questions Concurrent RTP Streams
1. Assuming that packet loss was reported, what is the distribution of the lost RTP Packets?
Concurrent RTP Streams (max)
Number of calls with
incoming RTP packets 2. Are any calls without RTP?
3. Are any calls with RTP?
4. Does this number match the number of Calls Connected * 2?
Number of calls without incoming RTP packets
Conclusions
This test methodology provided details of how to emulate with IxLoad Voice a SIP Registrar and Proxy Server to act as a Back to Back user agent. This configuration is presented in the context of measuring the performances of a Session Border Controller. The most challenging part of the configuration is setting correctly the dispatching rules for each activity.