Help with QoS values

Asterisk Asterisk SIP
1

I am running Asterisk 20.9.3 and when making test calls I’m seeing the following QoS output:

RTPAUDIOQOSMESBRIDGED= minrxmes=088.087887; maxrxmes=088.087887; avgrxmes=088.087887; stdevrxmes=000.000436; mintxmes=000.000000; maxtxmes=000.000000; avgtxmes=000.000000; stdevtxmes=000.000000;

RTPAUDIOQOSRTTBRIDGED= minrtt=000.000000; maxrtt=000.000000; avgrtt=000.000000; stdevrtt=000.000000;

RTPAUDIOQOSLOSSBRIDGED= minrxlost=000.000000; maxrxlost=000.000000; avgrxlost=000.000000; stdevrxlost=000.000000; mintxlost=000.000000; maxtxlost=000.000000; avgtxlost=000.000000; stdevtxlost=000.000000;

RTPAUDIOQOSJITTERBRIDGED=minrxjitter=000.000000;maxrxjitter=000.003750;avgrxjitter=000.000076;stdevrxjitter=000.000436;mintxjitter=000.000000;maxtxjitter=000.000000;avgtxjitter=000.000000;stdevtxjitter=000.000000;

RTPAUDIOQOSBRIDGED=ssrc=802340680;themssrc=705880408;lp=0;rxjitter=0.000000;rxcount=3881;txjitter=0.000000;txcount=4229;rlp=0;rtt=0.000000;rxmes=0.000000;txmes=88.087887

RTPAUDIOQOSMES= minrxmes=087.815391; maxrxmes=088.087887; avgrxmes=087.842915; stdevrxmes=000.001643; mintxmes=087.815391; maxtxmes=087.832487; avgtxmes=087.827678; stdevtxmes=000.004808;

RTPAUDIOQOSRTT= minrtt=000.022735; maxrtt=000.027816; avgrtt=000.025512; stdevrtt=000.001471;

RTPAUDIOQOSLOSS= minrxlost=000.000000; maxrxlost=000.000000; avgrxlost=000.000000; stdevrxlost=000.000000; mintxlost=000.000000; maxtxlost=000.000000; avgtxlost=000.000000; stdevtxlost=000.000000;

RTPAUDIOQOSJITTER=minrxjitter=000.000000;maxrxjitter=000.012125;avgrxjitter=000.002454;stdevrxjitter=000.001643;mintxjitter=000.000000;maxtxjitter=000.001625;avgtxjitter=000.000297;stdevtxjitter=000.000372;

RTPAUDIOQOS=ssrc=971871261;themssrc=817305193;lp=0;rxjitter=0.000125;rxcount=4256;txjitter=0.000625;txcount=3881;rlp=0;rtt=0.027038;rxmes=87.828914;txmes=87.828914

There are a few things that are confusing me with the above, so I have a few questions:

  1. Do the BRIDGED versions correspond to the egress channel and the non-BRIDGED versions to the ingress channel?
  2. Are the non-BRIDGED versions more or less reliable than the BRIDGED versions, or about the same?
  3. Are the rxmes and txmes values in RTPAUDIOQOS just a summary of the stats in RTPAUDIOQOSMES?
  4. If so then the rxmes value of 87.828914 doesn’t match any of the values in RTPAUDIOQOSMES (not even avgrxmes), so how do they relate - is it some kind of weighted average?
  5. If I’m after a single indicative value for the RX MES, would I be best advised to e.g. use rxmes in RTPAUDIOQOS rather than avgrxmes in RTPAUDIOQOSMES?
  6. For some reason the rxmes values are always zero in RTPAUDIOQOSBRIDGED but in RTPAUDIOQOSMESBRIDGED it’s the txmes values that are always zero - is this a bug where the RX/TX values have got swapped over and are being misreported in one of them, and if so then is it the RX or TX values that are correct for the BRIDGED versions?
  7. Is the same bug (the RX and TX values getting swapped) occurring with the non-BRIDGED versions as well (RTPAUDIOQOS and RTPAUDIOQOSMES), it’s just not as obvious because there are no zero values there so you can’t easily tell?
  8. Why are the values (RX in RTPAUDIOQOSBRIDGED, TX in RTPAUDIOQOSMESBRIDGED) zero at all - it seems like an MES value is missing?
  9. If I would like to monitor call quality across the board via MES values, would you generally advise recording a single MES value for RX ingress, one for TX ingress, one for RX egress and one for TX egress (so four in total) and monitoring each of those, or taking a different approach?

I’m aware that chan_sip is deprecated, so I understand that any bugs may not get fixed, but I’m stuck with it for the foreseeable, so it would really help if I could just understand which values I should be using and which ones are reliable!

2

Having done some more investigations, it looks like the rxmes values aren’t always zero in RTPAUDIOQOSBRIDGED after all, so ignore Q8, however I have managed to replicate the RX and TX values getting swapped in both the BRIDGED and non-BRIDGED versions (so the answer to Q7 is yes), if you could please confirm whether it’s the values in RTPAUDIOQOS and RTPAUDIOQOSBRIDGED that are the wrong way round, or the ones in RTPAUDIOQOSMES and RTPAUDIOQOSMESBRIDGED?

Many thanks!

3

Sorry, one more question!

  1. Are the RX and TX values equally reliable for both the BRIDGED and non-BRIDGED data, or is one more reliable than the other?

Just to confirm, Q7 and Q8 are now answered, so it’s just the other ones that are left.

Thanks again!