Comparison of OR and MDR Overhead and Delivery Ratios

1
Comparison of OR and MDR Overhead and Delivery
Ratios

• Stan Ratliff
• Cisco Systems

2
Description of Flooding Algorithms

• Overlapping Relays (OR)
• Described in draft-chandra-ospf-manet-ext-03
• Based on Multipoint Relay (MPR) flooding
  algorithm in OLSR
• MANET Designated Router (MDR)
• Described in draft-ogier-manet-ospf-extensio
  n-05

3
Changes to OR algorithm

• Added functionality described in
  draft-roy-ospf-smart-peering-00
• If new neighbor already in SPT, mark neighbor as
  FULL with respect to link advertisement.
• Defer DB synchronization until necessary.

4
Changes to Smart Peering

• Added functionality to smart peering
• Missed deadline for posting new draft for this
  IETF posting to come.
• Additions are referred to as Unsynchronized
  Adjacencies

5
Unsynchronized Adjacencies

• After new neighbor found in SPT and DB sync
  deferred,
• Link to new neighbor marked as Unsynchronized
  (New U Bit) in LSA
• A special SPT is created, ignoring links with
  U-bit set.
• This new SPT is consulted to determine whether
  DB synchronization is required, and is updated
  for all link state changes.

6
Other Changes from DT deliverable

• Velocity was increased to 16 meters/sec.
• Pause Time was decreased to 1.
• ACK Cache timeout was increased from dead
  interval (6 sec) to 100 seconds
• Multiple simulations were run, varying radio
  range from 100 meters to 200 meters in 20 meter
  increments.

7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
15
Conclusions

• The performance of OR has been enhanced with use
  of Unsynchronized Adjacencies.
• Overhead compared to Bi-Connected MDR is
  consistently lower.
• The higher-mobility characteristics tested are
  based on input provided by our customers.
• The Design Team should open the results and
  solicit input from the community in the interest
  of obtaining data on real-life deployment
  scenarios to base its final recommendation on.