Subject: [PMOL] Additional Comments - sip-perf-metrics-06

From: Daryl Malas <[email-masked]>
Date: Thu, 16 Sep 2010 15:12:54 -0600

All,

I received some additional questions and comments from Hadriel Kaplan, and after some short exchanges here are the results of the discussion.  We have come to an agreement with the proposed changes.  Please let us know if there are any concerns with these changes.

>> Section 4.9.2. is titled "Failed session completion", but the example is a
>> failed session attempt or setup, I think.
[DM] After looking over this, I agree with your point.  This sub-section
better fits with "Inaffective Session Attempt."

>> Session Disconnect Delay will get skewed disproportionally if the failed
>> disconnects (BYEs that never get a response) are included in it, since each
>> time that happens it'll be a 32-second time compared to milliseconds for good
>> cases.  Isn't it better to only measure successful cases for time delay, and
>> count the failed ones in a counter instead (I don't see a counter for the
>> failed ones).
[DM] I think this metric is similar to SRD and should included the following
statement:
"SDD is measured for both successful and failed session disconnects;
however, SDD for session disconnects ending in a failure MUST NOT be
combined in the same result with successful disconnects.  The duration
associated with success and failure results will likely vary substantially,
and the desired output time associated with each will be significantly
different in many cases."

>> Why is section 4.9 Session Completion Ratio "only used when at least one
>> proxy is involved in the dialog"??
> [DM] After reading through this metric, I am not sure of the value
> associated with this statement.  I think it can simply be removed.

Regards,

Daryl