Subject: [ipcdn] RE: rf mib draft v5 - comment period end Friday Oct 25

From: "Raftus, David" <[email-masked]>
Date: Mon, 28 Oct 2002 06:32:26 -0800

Hi Margo,

Thanks for your comments. However, I don't think your suggestion would
provide an actual real-world view of utilization as required by the MSOs.
Since the scheduler cannot have any gaps in the upstream, your model would
always provide close to 100% utilization, which is deceptive.  Also, UGS
grants from the CMTS when the channel is idle may increase the utilization
figure.

I do think that the actual upstream bursts received from the CM provide a
truer picture of utilization.

Thanks,
Dave 

************************************
David Raftus
Imedia Semiconductor
340 Terry Fox Drive, Suite 202
Ottawa Canada  K2K 3A2

[email-masked]           
613.592.1052  ext 222
************************************               

-----Original Message-----
From: Margo Dolas [mailto:[email-masked]]
Sent: Friday, October 25, 2002 2:46 PM
To: Raftus, David; Docsis 20 Reflector (E-mail); Docsis Oss Reflector
(E-mail); Ipcdn List (E-mail)
Subject: RE: rf mib draft v5 - comment period end Friday Oct 25

Dave,

I have one minor comment on the docsIfCmtsChannelUtilization object.

For granted slots, once the CMTS has made the grant, that bandwidth is
"utilized" regardless of whether the CM actually puts a burst in that slot
or not.  I think that the wording in the mib spec needs to be modified so
that any grant counts as "utilized".

How about the following text change?
Replace -
              Upstream Channel Utilization Index:
              The upstream channel utilization index is expressed as a
              percentage of minislots for which the CMTS received an
              upstream burst from any CM on the physical channel, regardless
              of burst type.

With -
              Upstream Channel Utilization Index:
              The upstream channel utilization index is expressed as a
              percentage of minislots for which the CMTS granted bandwidth
to
              any CM on the physical channel, regardless of burst type.

Regards,
Margo

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]On
Behalf Of Raftus, David
Sent: Friday, 18 October, 2002 3:55 PM
To: Docsis 20 Reflector (E-mail); Docsis Oss Reflector (E-mail); Ipcdn List
(E-mail)
Cc: Raftus, David
Subject: rf mib draft v5 - comment period end Friday Oct 25

Hi everyone,

Please find attached a draft of the Docsis RF Interface mib v5. The TOC and
compliance statements have not been updated, but suggestions received since
v4 regarding new mib objects have been incorporated after appropriate
massaging.

Comments are welcome on this draft until 5pm EST Friday October 25. At that
time an official version of the draft will be prepared for submission to the
IETF last call process, leading to RFC designation.

Thanks very much,
Dave

************************************
David Raftus
Imedia Semiconductor
340 Terry Fox Drive, Suite 202
Ottawa Canada  K2K 3A2

[email-masked]
613.592.1052  ext 222
************************************

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---

From: "Margo Dolas" <[email-masked]>
Date: Mon, 28 Oct 2002 15:49:16 -0500

Dave,

I think that you misunderstood what I meant by granted slots.  Granted slots
are unicast slots granted to a real CM on the plant; grants assigned to the
null SID and contention regions are not considered granted slots.

I would also argue that UGS grants from the CMTS increase the utilization
figure
whether or not the channel is idle.  This is because whether the CM uses it
or not,
it is still bandwidth that the CMTS cannot grant to another CM.

However, in order to measure the utilization of contention regions, the
actual
upstream burst needs to be measured.

I think that the text needs to be updated to adequately cover both of these
cases.
I suggest the following clarification -

              Upstream Channel Utilization Index:
              The upstream channel utilization index is expressed as a
              percentage of minislots utilized on the physical channel,
              regardless of burst type.  For contention regions, utilized
              minislots are those in which the CMTS received an upstream
              burst from any CM on the physical channel.  For all other
              regions, utilized minislots are those in which the CMTS
              granted bandwidth to any unicast SID on the physical channel.

If the vendor community chooses to go along with Greg's suggestion, I
believe
that this distinction needs to be maintained.

Regards,
Margo

-----Original Message-----
From: Raftus, David [mailto:[email-masked]]
Sent: Monday, 28 October, 2002 9:32 AM
To: 'Margo Dolas'; Raftus, David; Docsis 20 Reflector (E-mail); Docsis
Oss Reflector (E-mail); Ipcdn List (E-mail)
Subject: RE: rf mib draft v5 - comment period end Friday Oct 25

Hi Margo,

Thanks,
Dave

[email-masked]
613.592.1052  ext 222

-----Original Message-----
From: Margo Dolas [mailto:[email-masked]]
Sent: Friday, October 25, 2002 2:46 PM
To: Raftus, David; Docsis 20 Reflector (E-mail); Docsis Oss Reflector

Dave,

With -

Regards,
Margo

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

Hi everyone,

Thanks very much,
Dave

[email-masked]
613.592.1052  ext 222