Subject: [Ospf-wireless-design] UPDATE to comparative results

From: "Spagnolo, Phillip A" <[email-masked]>
Date: Fri, 10 Jun 2005 11:35:40 -0700

All,

We have been working to update our comparative results based on the
comments we received on the list from Richard.  We have now rerun all of
the data, and we have added a few more items.  We are not including the
chapter here, but we will summarize the changes.  If you would like to
see the new chapter, send an e-mail to Tom or I.  We are not bulk
e-mailing the file because of the size of the document and the results
have not changed significantly.  We will send out new documentation when
we get a large number of new results.

CHANGES TO THE CODE
-BackupWaitInterval=2000msec as opposed to 1000msec.  This allows enough
time for acks to arrive at BDRs, since the AckInterval = 1800 msec.
-The retransmit timer is reset by a BMDR if it floods a Backup LSA.
-An immediate multicast ack is sent upon receiving a duplicate unicast
LSA.
-An LSA header is not included in the database exchange packet when the
neighbor is know to have the LSA. (NOTE:  this change has not been
simulated, so we can keep a more equal comparison)

ADDITIONS/CHANGES TO THE REPORT
-The terminology for Richard's extensions is MDR = MANET Designated
Router and BMDR = Backup MANET Designated Router
-All results have now been simulated from 10 to 70 nodes.  (PTMP was
only simulated to 50 nodes after which it collapses).
-Comparison of differential hellos
-According to Richard's comment route quality = (recv pkts + fwd
pkts)/recv pkts) 
-MDR scaling up to 110 nodes for biconnected adjacencies and (B)MDR full
LSAs

NEW RESULTS
-Baseline comparison of overhead for ORs and MDRs (full topology)
basically overlaps.  We do not see the deviation at 50 nodes as seen in
the previous results.
-Baseline ORs and MDRs begin to degrade at 60 nodes (when overhead
reaches 4 or 5 Mbps)
-Improvements due to incremental/differential hellos have 2nd order
effects.
-The new formula for the route quality gives more insight into the
quality of the routes.
-At 110 nodes, MDRs with biconnected adjacencies and (B)MDR full LSAs
yields 887kbps overhead with a 0.951 delivery ratio.

NEXT STEPS
Our next step is to broaden the density/mobility scenarios tested.

Phil Spagnolo 
Network Technology Engineer 
The Boeing Company 
Phone:  (425) 865-6723

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---

From: Richard Ogier <[email-masked]>
Date: Thu, 23 Jun 2005 09:57:52 -0700

All,

>yields 887kbps overhead with a 0.951 delivery ratio.
I want to point out that the database exchange optmization
that is proposed in my draft, and also described in my email
of May 22, was not used in this simulation. This optimization
reduces the overhead of DD packets by about 50%.
Phil sent me more detailed overhead results (see below),
which show that the overhead due to DD packets is 339.26 kbps.
With the optimization, this will be reduced by about 170 kbps,
resulting in a total overhead of about 717 kbps, which is
about 20% less than what Phil obtained.
(I realize that Phil did not include the dbex optimization for
comparison reasons, but for 110 nodes I am not sure what we
are comparing to, and it is also important to know how
well the protocol scales.)

Richard

OSPFv3 Statistics
           | Packets          Bytes         Kbps
----------------------------------------------------
Hello       |   49500      16907168      150.29
LSAck       |   54429      14665084      130.36
LSR         |    2673        137256        1.22
DBDESC      |   37238      38166196      339.26
LSU         |   60629      29958076      266.29
  LSUfld    |     33941      16300796      144.90
  LSUuni    |     26688      13657280      121.40
    LSUcol  |         467        383040        3.40
    LSUrxmt |       22129      10617764       94.38
    LSUdbex |        1273        832924        7.40
    LSUstale|        2819       1823552       16.21
            |
Total       |  204469      99833780      887.41