Subject: [bmwg] Comment on OSPF intra-area Benchmarking

From: Yasuhiro Ohara <[email-masked]>
Date: Thu, 20 Feb 2003 22:37:52 +0900 (JST)

Hi, though I guess I roughly followed this ML's archive,
sorry if it's a duplication.

I read the draft-ietf-bmwg-ospfconv-intraarea-03.txt, felt it is a
good work, but have a few comments, most of them are in terms of
clarification.

First, minor thing, I felt it's hard to read the draft because
all the reference topologies are gathered in Sec 7 so I had to turn
the page back and forth ... I guess it's easier the topologies are
at the beggining of each section, even if those are spread across
document (I don't mean it should be duplicated). At least,
naming them and referencing with those names is better than
referencing the number ...

It would be clearer if you describe more about the differences
between the section 9.1. "Forming Adjacencies on Point-to-Point Link
Initialization" and the section 9.2. "Forming Adjacencies on
Point-to-Point Links". 9.1 means the time from L2 link up to adjacency
forming, while 9.2 means the time from those OSPF starts forming
adjacency to completion of the forming, doesn't they ?
9.2 is more specific test and better be described earlier than 9.1, IMO.
Then the duplication of text may become less and readers can easily
think of the fact that we can calculate the time from L2 link up to
OSPF starts on the link by subtracting 9.1's result from 9.2's result.

The section 9.3's title should be "Forming adjacencies with Information
Already in the Database", rather than "Link Up", which is confusing
with L2 link up.

9.4. "Initial SR-Convergence Time on a DR electing (broadcast) network"
and 9.7. "Designated Router Election Time on A Broadcast Network" are
very similar test and should be placed nearby. Futher, to evaluate
the accurate DR-Election time, you should subtract the 9.7's result
from 9.4's result. Is this wrong ?

You'd better unify the terminology, for example either "DR" or
"Designated Router".

9.4's last line include typo:
           broadcast network. Variations in the LSA sets and other fac-
           tors shoul dbe noted in the test results.
                ---------

9.6's title "Broadcast Media Link Down with Layer 3 Detection",
Broadcast Media seems to be wrong, as you specified that both link
in topology 4 are point-to-point in section 9.5.
I prefer those titles be:
9.5. "Point-to-point Link Down with Layer 2 Detection"
9.6. "Point-to-point Link Down with Layer 3 Detection"

Last, from someone's message in the mail archive:
"Well-defined Convergence methodology can be applied to ISIS or OSPF.",
I don't think so. Convergence time is essentially defined the time
between protocol events. If protocols differ, protocol events also
differ so the convergence time should be defined for each protocol.

regards,
yasu

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From: "Manral, Vishwas" <[email-masked]>
Date: Thu, 20 Feb 2003 12:39:12 -0500

Hi Yasu,

Thanks a lot for your comments. Most of them are very helpful.

My comments are inline with a VM> prefixed. Please let me know if you agree.

Thanks,
Vishwas

-----Original Message-----
From: Yasuhiro Ohara [mailto:[email-masked]]
Sent: Thursday, February 20, 2003 7:08 PM
To: [email-masked]
Subject: [bmwg] Comment on OSPF intra-area Benchmarking

VM> Thanks a lot.

First, minor thing, I felt it's hard to read the draft because
all the reference topologies are gathered in Sec 7 so I had to turn
the page back and forth ... I guess it's easier the topologies are
at the beggining of each section, even if those are spread across
document (I don't mean it should be duplicated). At least,
naming them and referencing with those names is better than
referencing the number ...
VM> I guess I understand the problem. We will try to give a name to the
topologies. Any hints on what they should be will be helpful.

VM> Yes, Yasu, you got it right. We will clarify that.

9.2 is more specific test and better be described earlier than 9.1, IMO.
Then the duplication of text may become less and readers can easily
think of the fact that we can calculate the time from L2 link up to
OSPF starts on the link by subtracting 9.1's result from 9.2's result.
VM> The difference is the delay, between the L2 comming up to the actual
protocol packet exchange starting. 

VM> I agree here.

VM> Ok.

VM> OK

VM> I guess the link type would not matter for the 9.6 test case, as in OSPF
unlike in ISIS(where DR hello interval is different from normal hello
interval). 

VM> We have called it Layer-3 Broadcast because, link down on a broadcast is
generally noted thru Layer 3 detection, while on a P2P link it is Layer-2
detection itself.

VM> I agree.