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

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

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.
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.

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 ?
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. 

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.
VM> I agree here.

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".
VM> Ok.

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.
                ---------
VM> OK

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"

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.

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.
VM> I agree. 

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---

From: Yasuhiro Ohara <[email-masked]>
Date: Fri, 21 Feb 2003 03:06:51 +0900 (JST)

> generally noted thru Layer 3 detection, while on a P2P link it is Layer-2

Agreed, but then removing "Broadcast" from title and
describing the above reason why you don't distinguish the two link type
will be more kind to readers.

I'll prefer below more, FYI:
9.5. "Link Down Detection Time with Layer 2 Method on Point-to-point"
9.6. "Link Down Detection Time with Layer 3 Method"

> topologies. Any hints on what they should be will be helpful.

Manral you know I'm not native english speaker, so give me a break ;p)
I believe others can give more appropriate names than I can.

> from 9.4's result. Is this wrong ?

I am very interested in knowing whether the last two sentences are correct
or not.

regards,
yasu

---

From: Yasuhiro Ohara <[email-masked]>
Date: Fri, 21 Feb 2003 03:06:51 +0900 (JST)

regards,
yasu