Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

From: "Margo Dolas" <[email-masked]>
Date: Wed, 29 Jan 2003 14:36:25 -0500

Andre and Lucy,

I believe that the test failures occurred because the spec was unclear in
the past.  The original understanding was that the
docsQosServiceFlowPolicedDropPkts counter include only packets dropped in
violation of the Max(T) equation.  However, with failures at tComLabs dues
to lack of clarity in the spec, many vendors coded to the test.

I thought that adding a new counter to count UGS packets dropped because the
packet exceeds the UGS grant would add an appropriate place to count these
dropped packets.  However, having said this, my objective is clarity in the
descriptions.  If the consensus is to count the dropped UGS packets in the
docsQosServiceFlowPolicedDropPkts counter, the description should be changed
to explicitly state this.

Regards,
Margo

-----Original Message-----
From: Pollak, Lucy [mailto:[email-masked]]
Sent: Wednesday, 29 January, 2003 1:55 PM
To: 'Lejeune, Andre'; Margo Dolas; Murwin William-LWM008; 'Docsis-Oss
(E-mail)'; 'IPCDN (E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

André.
I do not think that to count something twice is so bad. The ifOutDiscard
counter is integrated counter which shows the sum of all dropped packets on
US. The docsQosServiceFlowPolicedDropPkts is per interface counter and give
more detailed information. Again, I do not see a reason to change
docsQosServiceFlowPolicedDropPkts definition.
Thanks.
Lucy

-----Original Message-----
From: Lejeune, Andre [mailto:[email-masked]]
Sent: Wednesday, January 29, 2003 8:43 PM
To: Pollak, Lucy; Margo Dolas; Murwin William-LWM008; 'Docsis-Oss
(E-mail)'; 'IPCDN (E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

In trying to make sure that the text was as clear as possible, I think I
lost sight of the general goal, which should be to ensure that each dropped
packet is counted somewhere and counted only once. We too implemented the
counter to include UGS dropped packets, in particular if the rt policy is
set to drop UGS packets that are too large.

In reality, there are only 2 counters that count dropped packets:
ifOutDiscard and docsQosServiceFlowPolicedDropPkts. So if a UGS packet needs
to be dropped, where is it counted if it is not in
docsQosServiceFlowPolicedDropPkts?

André "does not know what he wants" L.

-----Original Message-----
From: Pollak, Lucy [mailto:[email-masked]]
Sent: Wednesday, January 29, 2003 12:00 PM
To: 'Lejeune, Andre'; Margo Dolas; Murwin William-LWM008; 'Docsis-Oss
(E-mail)'; 'IPCDN (E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

Margo and André.
I want to understand the reason for this change. I also familiar with this
discussion and in the beginning understood "especially to limit the maximum
rate of the flow" as "only to limit the maximum rate of the flow". But with
this understanding we failed tComLabs tests. Now, I guess, most of the CMs
already implemented this counter as integrated counter:
Max rate + max size + grant size + grant rate dropped packets.
And it seems the correct behavior, if somebody wants to compare classified
packets against dropped+send. I suppose, for backward compatibility we need
to leave docsQosServiceFlowPolicedDropPkts as is or even add the definition
that it will count all dropped packets. In addition, I agree, we may add the
set of reason's defined packet counters:
docsQosServiceFlowSizeDropPkts
docsQosServiceFlowRateDropPkts
I do not see a reason to differentiate UGS and other SF types. In definition
we can tell that MAX rate or grant rate is the reason for the drop. The same
about size.
I do not see a reason to change delayed packet also. Again, "especially"
gives us opportunity to apply it to UGS also. The SF type will not be
changed on-the-fly. What is the problem to show the same information for
UGS?
Regards.
Lucy
-----Original Message-----
From: Lejeune, Andre [mailto:[email-masked]]
Sent: Wednesday, January 29, 2003 12:41 AM
To: Margo Dolas; Lejeune, Andre; Murwin William-LWM008; 'Docsis-Oss
(E-mail)'; 'IPCDN (E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

Looks much better! I like it.

Thanks,
André

-----Original Message-----
From: Margo Dolas [mailto:[email-masked]]
Sent: Tuesday, January 28, 2003 5:19 PM
To: Lejeune, Andre; Murwin William-LWM008; 'Docsis-Oss (E-mail)'; 'IPCDN
(E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

Andre,

In thinking about it a bit more, I'd prefer to see more explicit text
for the policed packets.  What do you think of the following text?

For the docsQosServiceFlowPolicedDropPkts description - "This object
counts only packets dropped in violation of the Maximum Sustained
Traffic Rate.  This object will always report a value of 0 for UGS
flows because the Maximum Sustained Traffic Rate does not apply."

For the docsQosServiceFlowPolicedDelayPkts description - "This object
counts only packets delayed in violation of the Maximum Sustained Traffic
Rate.  This object will always report a value of 0 for UGS flows because
the Maximum Sustained Traffic Rate does not apply."

Regards,
Margo

-----Original Message-----
From: [email-masked]
[mailto:[email-masked]]On Behalf Of Margo Dolas
Sent: Tuesday, 28 January, 2003 4:18 PM
To: Lejeune, Andre; Murwin William-LWM008; 'Docsis-Oss (E-mail)'; 'IPCDN
(E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

Andre,

I agree with your simplification.

The new text for the docsQosServiceFlowPolicedDropPkts description would
then be - "This object counts only packets dropped in violation of the
Maximum Sustained Traffic Rate.  This object does not apply to UGS flows
because the Maximum Sustained Traffic Rate does not apply."

A similar simplification could be made to the description of
docsQosServiceFlowPolicedDelayPkts.  The new text would be - "This object
counts only packets delayed in violation of the Maximum Sustained Traffic
Rate.  This object does not apply to UGS flows because the Maximum Sustained
Traffic Rate does not apply."

Regards,
Margo

-----Original Message-----
From: Lejeune, Andre [mailto:[email-masked]]
Sent: Tuesday, 28 January, 2003 2:08 PM
To: Margo Dolas; Lejeune, Andre; Murwin William-LWM008; 'Docsis-Oss
(E-mail)'; 'IPCDN (E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

I understand why I did not read this text properly then. I took the last
sentence out of context. I don't think I had to stretch my imagination that
much to take it out of context, it does not make any mention of UGS, and
when the Maximum Sustained Traffic Rate is exceeded, the packet arrival rate
does exceed the packet transmission rate. Instead of providing a series of
examples for UGS flows, would it not be simpler to replace it with a
statement that the parameter does not apply to UGS flows, since Max
Sustained Rate is not applicable?

Thanks,

André

-----Original Message-----
From: Margo Dolas [mailto:[email-masked]]
Sent: Tuesday, January 28, 2003 1:14 PM
To: Lejeune, Andre; Murwin William-LWM008; 'Docsis-Oss (E-mail)'; 'IPCDN
(E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

Andre,

Maximum Sustained Rate is not applicable for UGS flows (per section 8.2.7
and table 8-4 of the RFI I09 spec), so packets cannot violate the Maximum
Sustained Rate for an UGS flow.  In an UGS flow, you only evaluate the
packet size versus the UGS grant size, and then queue the packet until you
receive a grant for the flow's SID.  If the queue is full (because packets
are arriving faster than the grant rate), then the packet is dropped and
ifOutDiscards is incremented.

Margo

-----Original Message-----
From: Lejeune, Andre [mailto:[email-masked]]
Sent: Tuesday, 28 January, 2003 11:17 AM
To: Margo Dolas; Murwin William-LWM008; 'Docsis-Oss (E-mail)'; 'IPCDN
(E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

I have a problem with the proposed text because I don't understand how to
distinguish packets that are in violation of the Maximum Sustained rate from
packets with arrival rate faster than the grant rate. What is the
difference?

Thanks,

André

-----Original Message-----
From: Margo Dolas [mailto:[email-masked]]
Sent: Monday, January 27, 2003 4:43 PM
To: Murwin William-LWM008; 'Docsis-Oss (E-mail)'; 'IPCDN (E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

William,

I agree with your changes.

Margo

-----Original Message-----
From: Murwin William-LWM008 [mailto:[email-masked]]
Sent: Monday, 27 January, 2003 4:16 PM
To: 'Margo Dolas'; 'Docsis-Oss (E-mail)'; 'IPCDN (E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

Responses in-line...

-----Original Message-----
From: Margo Dolas [mailto:[email-masked]]
Sent: Monday, January 27, 2003 3:57 PM
To: Murwin William-LWM008; 'Docsis-Oss (E-mail)'; 'IPCDN (E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

William,

I'd like to clarify the definition of docsQosServiceFlowPolicedDropPkts and
docsQosServiceFlowPolicedDelayPkts.  These counters have been discussed on
the reflector several times, and we have recently had discussions with
tComLabs over the ambiguity of the descriptions of these counters.

I suggest that the following sentences be added to the description of
docsQosServiceFlowPolicedDropPkts - "This object counts only packets dropped
in violation of the Max(T) equation.  Particularly for UGS flows, this
object does not include packets dropped or otherwise not sent on this flow
because the packet exceeds the UGS grant size.  This object does not count
packets dropped because the packet arrival rate is faster than the grant
rate (these packets should be counted in the ifOutDiscards counter)."  A new
counter should be created to describe packets dropped in violation of the
UGS grant size.   Packets sent on the primary service flow in violation of
the UGS grant size should be counted on the primary service flow's counters.

We would like change the above test to be:
"This object counts only packets dropped
in violation of the Maximum Sustained Traffic Rate.  Particularly for UGS
flows, this
object does not include packets dropped or otherwise not sent on this flow
because the packet exceeds the UGS grant size.  This object does not count
packets dropped because the packet arrival rate is faster than the grant
rate (these packets should be counted in the ifOutDiscards counter)."

Suggested text for the proposed counter - "For UGS flows, the number of
packets dropped because the packet exceeds the UGS grant size.  This object
does not count packets sent on the primary flow based on the
request-transmission policy settings.  For non-UGS flows, this counter
returns zero."

The new object would be:

docsQosServiceUgsDropPkts OBJECT-TYPE
    SYNTAX          Counter32
    MAX-ACCESS      read-only
    STATUS          current
    DESCRIPTION    "For UGS flows, the number of
                    packets dropped because the packet exceeds the UGS grant
                    size.  This object does not count packets sent on the
                    primary flow based on the request-transmission policy
                    settings.  For non-UGS flows, this counter returns
zero."
    ::= { docsQosServiceFlowStatsEntry 10 }

I suggest that the following sentences be added to the description of
docsQosServiceFlowPolicedDelayPkts - "This object counts only packets
delayed in violation of the Max(T) equation.  Particularly for UGS flows,
this object does not count packets queued awaiting grants."

Again just change "Max(T) equation" to "Maximum Sustained Traffic Rate"

I suggest that the following sentence be added to the description of
docsQosServiceFlowPkts - "Particularly for UGS flows, packets sent on the
primary service flow in violation of the UGS grant size should be counted
only on the primary service flow's counters."

Ok.

Regards,
Margo Dolas

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]On Behalf Of
Murwin William-LWM008
Sent: Friday, 24 January, 2003 11:29 AM
To: 'Docsis-Oss (E-mail)'; 'IPCDN (E-mail)'
Subject: [ipcdn] Deadline for Comments of QoS MIB version 7

Monday 1/27 is the Deadline for Comments of version 7 of the QoS MIB.

By Wednesday we will be posting version 7 of the QoS MIB on the IETF site.

Please review and get your comments in asap. Thanks.

Mike Patrick and Will Murwin

______________________________
William Murwin
Broadband Communications Sector
Motorola Inc.
Email: [email-masked]
Tel: (508) 851-8385

_______________________________________________
IPCDN mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/ipcdn

_______________________________________________
IPCDN mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/ipcdn

---

From: "Pollak, Lucy" <[email-masked]>
Date: Wed, 29 Jan 2003 20:55:21 +0200

André.

-----Original Message-----
From: Pollak, Lucy [mailto:[email-masked]]
Sent: Wednesday, January 29, 2003 12:00 PM
To: 'Lejeune, Andre'; Margo Dolas; Murwin William-LWM008; 'Docsis-Oss

Margo and André.
-----Original Message-----
From: Lejeune, Andre [mailto:[email-masked]]
Sent: Wednesday, January 29, 2003 12:41 AM
To: Margo Dolas; Lejeune, Andre; Murwin William-LWM008; 'Docsis-Oss

Thanks,
André

-----Original Message-----
From: Margo Dolas [mailto:[email-masked]]
Sent: Tuesday, January 28, 2003 5:19 PM
To: Lejeune, Andre; Murwin William-LWM008; 'Docsis-Oss (E-mail)'; 'IPCDN
(E-mail)'

Andre,

Regards,
Margo

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

Andre,

Regards,
Margo

-----Original Message-----
From: Lejeune, Andre [mailto:[email-masked]]
Sent: Tuesday, 28 January, 2003 2:08 PM
To: Margo Dolas; Lejeune, Andre; Murwin William-LWM008; 'Docsis-Oss

Thanks,

André

-----Original Message-----
From: Margo Dolas [mailto:[email-masked]]
Sent: Tuesday, January 28, 2003 1:14 PM
To: Lejeune, Andre; Murwin William-LWM008; 'Docsis-Oss (E-mail)'; 'IPCDN
(E-mail)'

Andre,

Margo

-----Original Message-----
From: Lejeune, Andre [mailto:[email-masked]]
Sent: Tuesday, 28 January, 2003 11:17 AM
To: Margo Dolas; Murwin William-LWM008; 'Docsis-Oss (E-mail)'; 'IPCDN
(E-mail)'

Thanks,

André

-----Original Message-----
From: Margo Dolas [mailto:[email-masked]]
Sent: Monday, January 27, 2003 4:43 PM
To: Murwin William-LWM008; 'Docsis-Oss (E-mail)'; 'IPCDN (E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

William,

Margo

-----Original Message-----
From: Murwin William-LWM008 [mailto:[email-masked]]
Sent: Monday, 27 January, 2003 4:16 PM
To: 'Margo Dolas'; 'Docsis-Oss (E-mail)'; 'IPCDN (E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

Responses in-line...

-----Original Message-----
From: Margo Dolas [mailto:[email-masked]]
Sent: Monday, January 27, 2003 3:57 PM
To: Murwin William-LWM008; 'Docsis-Oss (E-mail)'; 'IPCDN (E-mail)'
Subject: RE: [ipcdn] Deadline for Comments of QoS MIB version 7

William,

The new object would be:

Ok.

Regards,
Margo Dolas