Subject: Re: [xrblock] ISSUE: Early vs Late discard

From: [email-masked]
Date: Wed, 21 Dec 2011 14:21:40 +0800 (CST)

Your proposed text address my comments, Thanks!

Regards!

ZhaoJing

Shanghai Research Institution of China Telecom

------------------ 原始邮件 ------------------

发件人：Qin Wu

时　间：2011/12/21 10:00:29 星期三

收件人：[email-masked], xrblock

抄送人：

主　题：Re: [xrblock] ISSUE: Early vs Late discard

Hi,Jing:

Your suggestion make sense to me. That is to say the total of discard due to early arrival and discard due to late arrival are used to calculate

the fraction of packets discarded during gaps (i.e.,gap discard rate) specified in the burst-gap-discard draft. Therefore we should support

reporting such total discard during the measurement interval.

My proprosal to fix this is to allocate two bits for "Early Indication Flag" and redefine "Ealry Indication Flag" in draft-ietf-xrblock-rtcp-xr-discard as follows:

OLD TEXT

"

Early indication flag (E): 1bit

This field is used to indicate whether packets are discarded due

to early arrival or due to late arrival. This field MUST be set

to '1' if packets are discarded due to too early arrival and MUST

be set to '0' otherwise.

"

NEW TEXT

"

Early indication flag (E): 2bits

This field is used to indicate whether packets are discarded due

to early arrival or due to late arrival or due to both. This field MUST be set

to '1' if packets are discarded due to too early arrival and MUST

be set to '2' if packets are discarded due to late arrival. If packets are discarded

due to both early arrival and late arrival, this field MUST be set to '3'.

"

In this case, we can support three following cases using this 2 bit flag:

case 1: report the number of discarded packets due to early arrival

case 2: report the number of dicarded packets due to late arrival

case 3: report the total number of dicarded packets.

Does this address your comment?

Regards!

-Qin

----- Original Message -----

From:
[email-masked]

To:
xrblock

Sent: Tuesday, December 20, 2011 10:35 AM

Subject: [xrblock] ISSUE: Early vs Late discard

Hi,

Following the early Alan's comment on the list regarding early vs late discard, on October,30

http://www.ietf.org/mail-archive/web/xrblock/current/msg00113.html

His comment only applies to draft-ietf-xrblock-rtcp-xr-discard.

It was agreed that distinguishing early discard from late discard is a useful feature on the list. Therefore it is worth

having this implemented into the draft-ietf-xrblock-rtcp-xr-discard when we disccussed burst gap related drafts in IETF82 meeting.

In the Tapei meeting, Charles also had one comment relate to this issue: i.e., how to report both Early and late in the same interval?

That is to say if we distinguish early discard from late discard, do we need to discard due to both early arrival and late arrival.

After re-reading the draft-ietf-xrblock-rtcp-xr-discard, I believe the early motivation to write draft-ietf-xrblock-rtcp-xr-discard is
to only report the discard due to both early discard and late discard, i.e., number of packets discarded, this parameter will be used
to calculate the Gap discard rate specifed in the section 3.3 of draft-ietf-xrblock-rtcp-xr-burst-gap-discard and draft-zorn-xrblock-rtcp-xr-al-stat.

In the recent update of draft-xrblock-rtcp-xr-discard, it only support reporting early discard or late discard, but does not support reporting discard due
to both early arrival and late arrival. Therefore I suggest to update draft-xrblock-rtcp-xr-discard to support reporting discard due
to both early arrival and late arrival.

Also I believe the feature to distinguish Ealry vs late discard does not apply to draft-ietf-rtcp-xr-burst-gap-discard. Since this draft relies on
discard due to both early and late arrival described in the draft-ietf-xrblock-rtcp-xr-discard rather than discard to due to either early arrival
or late arrival.

Regards!

ZhaoJing

Shanghai Research Institution of China Telecom

_______________________________________________

xrblock mailing list

[email-masked]

https://www.ietf.org/mailman/listinfo/xrblock