I'm having a bit of trouble interpreting the jitter_ related data that I am getting out of XML CDR's in an attempt to measure how well a system is performing.

For example, I place a G.711 call over a private LAN between two idle systems using PCMU, the originator being static in a continuous loop, and the destination being "echo", with jitterbuffer_ms=60:200:20

At the 'echo' end, I examine the call-stats section of the XML CDR (below), and I am not sure what to make of the jitter_ values -- for example max_variance of 7076.55, and a loss_rate of 116.67 -- as I haven't been able to determine from the source code thus far what they are measuring, and what units they are working in.

Any pointers would be appreciated.

Cheers,

Simon

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<call-stats>

<audio>

<raw_bytes>817744</raw_bytes>

<media_bytes>817744</media_bytes>

<packet_count>4772</packet_count>

<media_packet_count>4772</media_packet_count>

<skip_packet_count>51</skip_packet_count>

<jitter_packet_count>4774</jitter_packet_count>

<dtmf_packet_count>0</dtmf_packet_count>

<cng_packet_count>0</cng_packet_count>

<flush_packet_count>0</flush_packet_count>

<largest_jb_size>0</largest_jb_size>

<jitter_min_variance>0.10</jitter_min_variance>

<jitter_max_variance>7076.55</jitter_max_variance>

<jitter_loss_rate>116.67</jitter_loss_rate>

<jitter_burst_rate>115.67</jitter_burst_rate>

<mean_interval>20.06</mean_interval>

<flaw_total>0</flaw_total>

<quality_percentage>100.00</quality_percentage>

</inbound>

<raw_bytes>812700</raw_bytes>

<media_bytes>812700</media_bytes>

<packet_count>4725</packet_count>

<media_packet_count>4725</media_packet_count>

<skip_packet_count>0</skip_packet_count>

<dtmf_packet_count>0</dtmf_packet_count>

<cng_packet_count>0</cng_packet_count>

<rtcp_packet_count>0</rtcp_packet_count>

<rtcp_octet_count>0</rtcp_octet_count>

</outbound>

<error-log>

<error-period>

<consecutive-flaws>0</consecutive-flaws>

<duration-msec>5560</duration-msec>

</error-period>

</error-log>

</audio>

</call-stats>