Study on Net Manager Selection Algorithm
IEEE P1394.1 Working Group
St.Petersburg, FL Meeting
June 09, 1998
Masa Akahane, Hisaki Hiraiwa
Sony Corporation
[email protected]
[email protected]
Agenda
 Review on Subnet Structure
 Net Manager Selection (Revised)
 Concept and assumption
 Step by step transition
 Open Issue
 Conclusion
Sony Corporation
2
Review on Subnet Structure

Disadvantages of Single Plane Structure
 Need to manage up to 1023
buses
 Configuration (re-routing, manager selection, etc.) could be a
significant load when the topology changes

Advantages of Hierarchical Structure (Subnet)
 Net manager and subnet managers handle up to 31
subnets and buses respectively in the case of two 5 bits
 Localize the reconfiguration within a subnet when the
topology changes
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3
Single Plane Architecture
Reconfiguration could be a heavy load in case a critical path is torn !
Bridge Manager
Sony Corporation
4
Hierarchical Architecture
- Node_ID consists of sunbet_ID(5bit), bus_ID(5bit) and phy_ID(6bit)
Subnet Manager
3
2
0
Subnet Manager
1
0
0
3
4 1
4 4
2
1
2
3
2
1
2
1
0
2
2
4
1
1
1
0
5
3
4
1
0
0
1
Sony Corporation
4
1
0
Subnet Manager
3
4 Subnet Manager 5
5
3
3
2
3 3
0
3
2
4
6
0
0
1
5
Today’s Contribution
- Bridge Manager or Subnet Manger selection scheme has to
be specified anyway
- Subnet Manager selection scheme is supposed to be the
same as Bridge Manager selection
- Net Manager selection scheme is the extra portion if we
choose Subnet structure
Architecture Choice
Single Plane
Need to be specified Bridge Manager Selection
Sony Corporation
Subnet
Subnet Manager Selection
Net Manager Selection
6
Net Manager Selection Overview

Assumption





Subnet managers should be selected in advance
Classified criteria should be specified for “Rank” table
Every subnet manager has the ability to be the Net Manager
Trigger of the start of selection should be specified under “Reset
Notification” discussion
Procedure



Exploring the Net Manager by “Duel” with Rank table
EUI-Duel is placed as tiebreaker if Rank-Duel results in Draw
Status Register and some commands are prepared for the selection
process
Sony Corporation
7
Duel Rules

Duel is based on Rank table
 The higher rank holder wins the duel
 The loser’s duel_rank is overwritten with the winner’s
In the case of draw, bit-reversed EUI is used for
tiebreaker
 If the tiebreaker results in draw, it tells there is a
loop

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8
Status
No_Duel
Wait_Result
Child
Child_Finish
Parent
Parent_Finish
Draw_Finish
Ready for Duel
Mgr_Rank is stored in the Config-ROM
Duel_Rank is copied from Mgr_Rank
Status Register is set to “No_Duel”
Initial status
Waiting for the duel result status
Loser to be confirmed
Confirmed loser
Winner to be confirmed
Confirmed winner
Tied situation (It happens when a loop exists)
#
0
1
2
Mgr_Rank=3
0
0
1
0
Mgr_Rank=5 3
2
Node_ID
(1f, 0, 4)
(1f, 1, 0)
2
4 4
2
1
1
1
Status
No_Duel
No_Duel
0
2
2
4
3
4
1
0
5
5
Sony Corporation
Status
No_Duel
4
Mgr_Rank=6
0
Duel_Rank=6
6
0
3
2
Node_ID
0 Status
(1f, 1, 5) 1
No_Duel
(1f, 3, 2)
No_Duel
Node_ID
(1f, 1, 3)
1
Duel_Rank=9
3
#
02
1
3 3
Mgr_Rank=9
0
3
4
3
#
0
1
1
0
5
Status
No_Duel
No_Duel
No_Duel
2
1
2
3
Duel_Rank=5
#
0
1
4 1
Duel_Rank=3
3
Node_ID
(1f, 2, 1)
(1f, 1, 2)
(1f, 1, 3)
4
0
1
9
Duel in Progress - 1
• Duel is originated by “Duel_Request” command and it is generated by every
Subnet Manager independently.
• The result of Duel is notified by “Duel_Result” command.
#
0
1
2
Mgr_Rank=3
0
0
1
0
Mgr_Rank=5 3
2
Node_ID
(1f, 0, 4)
(1f, 1, 0)
2
4 4
2
1
1
1
Status
No_Duel
Child
No_Duel
0
2
2
4
3
4
1
0
5
5
Sony Corporation
Status
No_Duel
4
Mgr_Rank=6
0
Duel_Rank=6
6
0
3
2
Node_ID
0 Status
(1f, 1, 5) 1
No_Duel
(1f, 3, 2)
No_Duel
Node_ID
(1f, 1, 3)
1
Duel_Rank=9
3
#
02
1
3 3
Mgr_Rank=9
0
3
4
3
#
0
1
1
0
5
Status
No_Duel
Parent
No_Duel
No_Duel
2
1
2
3
Duel_Rank=5
#
0
1
4 1
Duel_Rank=3
3 -> 5
3
Node_ID
(1f, 2, 1)
(1f, 1, 2)
(1f, 1, 3)
4
0
1
10
Duel in Progress - 2
#
0
1
2
Mgr_Rank=3
0
0
1
0
Mgr_Rank=5 3
2
Node_ID
(1f, 0, 4)
(1f, 1, 0)
2
4 4
2
1
1
1
Status
Child
No_Duel
0
2
2
4
3
4
1
0
5
5
Sony Corporation
Status
No_Duel
Child
4
Mgr_Rank=6
0
Duel_Rank=6
6
0
3
2
Node_ID
0 Status
(1f, 1, 5) 1
No_Duel
(1f, 3, 2)
No_Duel
Node_ID
(1f, 1, 3)
1
Duel_Rank=9
3
#
02
1
3 3
Mgr_Rank=9
0
3
4
3
#
0
1
1
0
5
Status
No_Duel
Parent
No_Duel
No_Duel
Parent
2
1
2
3
Duel_Rank=5
#
0
1
4 1
Duel_Rank=5
5 -> 6
3
Node_ID
(1f, 2, 1)
(1f, 1, 2)
(1f, 1, 3)
4
0
1
11
Duel in Progress - 3
#
0
1
2
Mgr_Rank=3
0
0
1
0
Mgr_Rank=5 3
2
Node_ID
(1f, 0, 4)
(1f, 1, 0)
2
4 4
2
1
1
1
Status
Child
No_Duel
0
2
2
4
3
4
1
0
5
5
Sony Corporation
Status
Child
4
Mgr_Rank=6
0
Duel_Rank=6
6
0
3
2
Node_ID
0 Status
(1f, 1, 5) 1
No_Duel
(1f, 3, 2)
No_Duel
Child
Node_ID
(1f, 1, 3)
1
Duel_Rank=9
3
#
02
1
3 3
Mgr_Rank=9
0
3
4
3
#
0
1
1
0
5
Status
No_Duel
No_Duel
Parent
No_Duel
Parent
2
1
2
3
Duel_Rank=5
#
0
1
4 1
Duel_Rank=6
6 -> 9
3
Node_ID
(1f, 2, 1)
(1f, 1, 2)
(1f, 1, 3)
4
0
1
12
Duel in Progress - 4
#
0
1
2
Mgr_Rank=3
0
0
1
0
Mgr_Rank=5 3
2
Node_ID
(1f, 0, 4)
(1f, 1, 0)
2
4 4
2
1
1
1
Status
No_Duel
Child
No_Duel
Parent
0
2
2
4
3
4
1
0
5
5
Sony Corporation
Status
Child
4
Mgr_Rank=6
0
Duel_Rank=6
6
0
3
2
Node_ID
0 Status
(1f, 1, 5) 1
No_Duel
Child
(1f, 3, 2)
Child
Node_ID
(1f, 1, 3)
1
Duel_Rank=9
3
#
02
1
3 3
Mgr_Rank=9
0
3
4
3
#
0
1
1
0
5
Status
No_Duel
Parent
No_Duel
2
1
2
3
Duel_Rank=9
5 -> 9
#
0
1
4 1
9
3
Node_ID
(1f, 2, 1)
(1f, 1, 2)
(1f, 1, 3)
4
0
1
13
Duel in Progress - 5
#
0
1
2
Mgr_Rank=3
0
0
1
0
Mgr_Rank=5 3
2
Node_ID
(1f, 0, 4)
(1f, 1, 0)
2
4 4
2
1
1
1
Status
No_Duel
Parent
0
2
2
4
3
4
1
0
5
5
Sony Corporation
Status
Parent
Child
4
Mgr_Rank=6
0
Duel_Rank=6
6 -> 9
6
0
3
2
Node_ID
0 Status
(1f, 1, 5) 1
Child
(1f, 3, 2)
Child
Node_ID
(1f, 1, 3)
1
Duel_Rank=9
3
#
02
1
3 3
Mgr_Rank=9
0
3
4
3
#
0
1
1
0
5
Status
No_Duel
Parent
No_Duel
Child
2
1
2
3
9
#
0
1
4 1
9
3
Node_ID
(1f, 2, 1)
(1f, 1, 2)
(1f, 1, 3)
4
0
1
14
Duel in Progress - 6
#
0
1
2
Mgr_Rank=3
0
0
1
0
Mgr_Rank=5 3
2
Node_ID
(1f, 0, 4)
(1f, 1, 0)
2
4 4
2
1
1
1
Status
Draw_Finish
No_Duel
Parent
0
2
2
4
3
4
1
0
5
5
Sony Corporation
Mgr_Rank=6
9
6
0
3
4
Status
Parent
4
0
2
Node_ID
0 Status
(1f, 1, 5) 1
Child
(1f, 3, 2)
Child
Node_ID
(1f, 1, 3)
1
Duel_Rank=9
3
#
02
1
3 3
Mgr_Rank=9
0
3
4
3
#
0
1
1
0
5
Status
Draw_Finish
No_Duel
Parent
Child
2
1
2
3
9
#
0
1
4 1
9
3
Node_ID
(1f, 2, 1)
(1f, 1, 2)
(1f, 1, 3)
0
1
15
Duel in Progress - 7
Those Subnet Managers whose Status :
- doesn’t contain “No_Duel” nor “Child” and
- contains “Parent”
can initiate “Finish” command.
Mgr_Rank=3
0
0
1
0
Mgr_Rank=5 3
2
Node_ID
(1f, 0, 4)
(1f, 1, 0)
4 4
2
1
1
1
Status
Draw_Finish
Parent
0
2
2
4
3
4
1
0
3 3
5
5
Sony Corporation
Mgr_Rank=6
9
6
0
3
4
Status
Parent_Finish
Parent
4
0
2
Node_ID
0 Status
(1f, 1, 5) 1
Child
(1f, 3, 2)
Child
Node_ID
(1f, 1, 3)
1
Duel_Rank=9
3
#
02
1
#
0
Mgr_Rank=9
0
3
4
3
Status
Draw_Finish
Parent
Child_Finish
Child
1
1
0
5
Node_ID
(1f, 2, 1)
(1f, 1, 2)
(1f, 1, 3)
2
1
2
3
9
#
0
1
4 1
9
3
2
#
0
1
2
0
1
16
Duel in Progress - 8
#
0
1
2
Mgr_Rank=3
0
0
1
0
Mgr_Rank=5 3
2
Node_ID
(1f, 0, 4)
(1f, 1, 0)
2
4 4
2
1
1
1
Status
Draw_Finish
Parent_Finish
Parent
0
2
2
4
3
4
1
0
5
5
Sony Corporation
4
Parent_Finish
Mgr_Rank=6
9
6
0
3
Status
4
0
2
Node_ID
0 Status
(1f, 1, 5) 1
Child
(1f, 3, 2)
Child_Finish
Child
Node_ID
(1f, 1, 3)
1
Duel_Rank=9
3
#
02
1
3 3
Mgr_Rank=9
0
3
4
3
#
0
1
1
0
5
Status
Draw_Finish
Parent
Child_Finish
2
1
2
3
9
#
0
1
4 1
9
3
Node_ID
(1f, 2, 1)
(1f, 1, 2)
(1f, 1, 3)
0
1
17
Duel in Progress - 9
#
0
1
2
Mgr_Rank=3
0
0
1
0
Mgr_Rank=5 3
2
Node_ID
(1f, 0, 4)
(1f, 1, 0)
2
4 4
2
1
1
1
Status
Draw_Finish
Parent_Finish
0
2
2
4
3
4
1
0
5
5
Sony Corporation
4
Parent_Finish
Mgr_Rank=6
9
6
0
3
Status
4
0
2
Node_ID
0 Status
(1f, 1, 5) 1 Child_Finish
Child
(1f, 3, 2)
Child_Finish
Node_ID
(1f, 1, 3)
1
Duel_Rank=9
3
#
02
1
3 3
Mgr_Rank=9
0
3
4
3
#
0
1
1
0
5
Status
Draw_Finish
Parent_Finish
Parent
Child_Finish
2
1
2
3
9
#
0
1
4 1
9
3
Node_ID
(1f, 2, 1)
(1f, 1, 2)
(1f, 1, 3)
0
1
18
Duel in Progress - 10
The Subnet Manager whose Status only contains either “Child_Finish” or “Draw_Finish” becomes
the Net Manager and the Net Manager initiates “Selection_End” command to all of neighbors.
#
0
1
2
Mgr_Rank=3
0
0
1
0
Mgr_Rank=5 3
2
Node_ID
(1f, 0, 4)
(1f, 1, 0)
2
4 4
2
1
1
1
Status
Draw_Finish
Parent_Finish
0
3
Mgr_Rank=9
0
3
4
3
4
1
0
5
5
4
Parent_Finish
Mgr_Rank=6
9
6
0
3
Status
4
0
2
Node_ID
0 Status
(1f, 1, 5) 1 Child_Finish
(1f, 3, 2)
Child_Finish
Node_ID
(1f, 1, 3)
1
Duel_Rank=9
3
#
02
1
Child_Finish
1
1
0
5
Parent_Finish
#
0
3 3
2
2
4
Status
Draw_Finish
2
1
2
3
9
#
0
1
4 1
9
3
Node_ID
(1f, 2, 1)
(1f, 1, 2)
(1f, 1, 3)
0
1
Winner !
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19
Duel in Progress - 11
Upon receiving “Selection_End”, it propagates “Selection_End” to the subnet manager
whose status is “Child_Finish”, if any.
#
0
1
2
Mgr_Rank=3
0
0
1
0
Mgr_Rank=5 3
2
Node_ID
(1f, 0, 4)
(1f, 1, 0)
2
4 4
2
1
1
1
Status
Draw_Finish
Parent_Finish
0
3
Mgr_Rank=9
0
3
4
3
4
1
0
5
5
4
Parent_Finish
Mgr_Rank=6
9
6
0
3
Status
4
0
2
Node_ID
0 Status
(1f, 1, 5) 1 Child_Finish
(1f, 3, 2)
Child_Finish
Node_ID
(1f, 1, 3)
1
Duel_Rank=9
3
#
02
1
Child_Finish
1
1
0
5
Parent_Finish
#
0
3 3
2
2
4
Status
Draw_Finish
2
1
2
3
9
#
0
1
4 1
9
3
Node_ID
(1f, 2, 1)
(1f, 1, 2)
(1f, 1, 3)
0
1
Winner !
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20
Duel Result
1) The winner A is the Net Manager
2) The net is logically broken down as a tree structure
3) Status information could be used for Net Configuration
B
A
C
Child
Child
C
B
DRAW
D
A
Sony Corporation
D
Child
21
Command and Status Summary

Commands




duel_request_up / _down
duel_result_up / _down
finish_up / _down
selection_end_up / _down
Duel origination
Response with duel result
Finish notification from the winner
Finish notification from a loser to the other losers
0
1
0
3
3
2
2
1
2
0
0
4 2
3
Sony Corporation
0
1
22
Command List - 1
duel_request_up
duel_request_down
destination_portal_id
command_code
Reserved
request_counter
command_code
Reserved
duel_EUI_hi
duel_EUI_hi
duel_EUI_lo
duel_EUI_lo
duel_rank
duel_rank
duel_result_up
destination_portal_id
command_code
source_portal_id
Reserved
Result
01- I win
10- You win
11- Draw
request_counter
duel_result_down
source_portal_id
command_code
Reserved
duel_EUI_hi
duel_EUI_hi
duel_EUI_lo
duel_EUI_lo
duel_rank
duel_rank
Sony Corporation
request_counter
Result
01- I win
10- You win
11- Draw
request_counter
23
Command List - 2
finish_up
finish_down
destination_portal_id
command_code
Reserved
source_portal_id
Reserved
command_code
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
selection_end_up
selection_end_down
destination_portal_id
command_code
Reserved
source_portal_id
command_code
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
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24
Open Issue

What makes the boundary between subnets?



“Loose Coupled Bridge” for wireless was implicit boundary but ...
The boundary should exist before the Subnet Manager selection starts
Ideas

Boundary between subnets should be specified either :

Two different products: 1) Inter-Bus Bridge or 2) Inter-Subnet Bridge


Putting dip-switch with user configurable


Users has to decide which one has to be fit for the use
Sounds against “Plug and Play”, however, such a large network needs some
level of user configuration anyway
Automatic configuration to build subnets

Very difficult !
Sony Corporation
25
Subnet Architecture
Who specifies those boundaries ?
Subnet Manager
3
2
0
Subnet Manager
1
0
0
3
4 1
4 4
2
1
2
3
2
1
2
1
0
2
2
4
1
1
1
0
5
3
4
1
0
0
1
Sony Corporation
4
1
0
Subnet Manager
3
4 Subnet Manager 5
5
3
3
2
3 3
0
3
2
4
6
0
0
1
26
Conclusion

Introduced the advantages of subnet structure
 Simplicity in terms of its hardware and software structure
Specified detail algorithm of Net Manager Selection
 Further Study

 Subnet Manager Selection Scheme
 Trigger of the start of the selection
 Subnet boundary issue
Sony Corporation
27