Last Call Review of draft-ietf-xrblock-rtcp-xr-loss-conceal-10
review-ietf-xrblock-rtcp-xr-loss-conceal-10-opsdir-lc-morton-2014-03-27-00
| Request | Review of | draft-ietf-xrblock-rtcp-xr-loss-conceal |
|---|---|---|
| Requested rev. | no specific revision (document currently at 12) | |
| Type | Last Call Review | |
| Team | Ops Directorate (opsdir) | |
| Deadline | 2014-03-28 | |
| Requested | 2014-03-20 | |
| Authors | Alan Clark, Glen Zorn, Claire Bi, Qin Wu | |
| Draft last updated | 2014-03-27 | |
| Completed reviews |
Genart Last Call review of -10 by Meral Shirazipour
(diff)
Genart Telechat review of -11 by Meral Shirazipour (diff) Secdir Last Call review of -10 by Steve Hanna (diff) Opsdir Last Call review of -10 by Al Morton (diff) |
|
| Assignment | Reviewer | Al Morton |
| State | Completed | |
| Review | review-ietf-xrblock-rtcp-xr-loss-conceal-10-opsdir-lc-morton-2014-03-27 | |
| Reviewed rev. | 10 (document currently at 12) | |
| Review result | Has Issues | |
| Review completed: | 2014-03-27 |
Review
review-ietf-xrblock-rtcp-xr-loss-conceal-10-opsdir-lc-morton-2014-03-27
This is the OPS-DIR review of the subject draft.
I note that this draft was reviewed by Vinayak Hegde for the pm-dir;
he reviewed version 05 on May 31st, 2013.
I find no new operational issues extending RTCP-XR with this new block,
but have the following comments for clarity.
Al
Interval Metric flag (I): 2 bit
This field is used to indicate whether the Loss Concealment
metrics are Sampled, Interval or Cumulative metrics:
I=10: Interval Duration - the reported value applies to the
most recent measurement interval duration between successive
metrics reports.
I=11: Cumulative Duration - the reported value applies to the
accumulation period characteristic of cumulative measurements.
I=01: Sampled Value - the reported value is a sampled
instantaneous value.
In this document, Loss Concealment Metrics can only be measured
over definite intervals, and cannot be sampled. Also, the value
I=00 is reserved for future use. Senders MUST NOT use the values
I=00 or I=01. If a block is received with I=00 or I=01, the
receiver MUST discard the block.
Since I=01 is not allowed, remove it from the list and simply
retain the explanation that follows (like I=00 was omitted).
(the text above occurs twice in the draft)
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SCS Threshold: 8 bits
The SCS Threshold is defined as the percentage of packets
corresponding to lost or discarded frames that must occur within a
one second period in order for the second to be classified as a
Severely Concealed Second. This is expressed in numeric format
0:8 and hence can represent a range of 0.1 to 25.5 percent loss or
discard.
A default threshold of 5% effective frame loss (50ms effective
frame loss ) per second is suggested.
Please provide the value of the default threshold setting.
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