Wireless Token Ring Protocol UDP Implementation

1
Wireless Token Ring Protocol UDP Implementation
Duke Lee, Mustafa Ergen, Jeff Ko, Ruchira Datta
2
Overview

• Accomplished Project Objectives
• Protocol Design Status
• Simulation
• UDP Implementation
• Conclusion

3
Accomplished Project Objectives

• Implemented Kernel Support Functions.
• Improvement of Protocol.
• Lean and flexible design.
• Improved user friendliness.
• Providing UDP user interface.
• Implementation of Simulation Platform.
• Simple Admission Control.
• Compatibility across different computer
  architecture.

4
Finite State Machine
5
Joining
Have_Token
J_M
H_M
F_J
I_H
I_M
Monitoring
J_F
M_F
M_I
M_O
S_M
Floating
Idle
F_I
I_F
S_F
I_O
I_S
B_F
O_F
Soliciting
Offline
S_O
Beginning
S_I
6
Transitions From/To Beginning
Beginning
Always
Floating
7
Transitions From/To Have_Token
Idle
received normal token with greater priority
output queue is nonempty
Have_Token
done transmitting
Monitoring
token_holding expired
8
States
Claim_token_timer_expires
Offline_timer_expires
Receive_Solicit_Successor
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Transitions From/To Offline
Idle
another ring not is_selfring
another ring not is_selfring
Offline
joined failed to transmit
Floating
offline expired
exceeded max token pass tries
Monitoring
token_pass expired
Soliciting
another ring not is_selfring
10
Transitions From/To Floating
another ring and is_selfring
Beginning
Idle
Idle
inring expired
claim token expired
always
Offline
offline expired
Floating
Joining
Joining
contention expired
got solicit_successor decided to join
failed to join
Monitoring
another ring and is_selfring
another ring and is_selfring
Soliciting
11
States
Receive_Implicit_Ack
Receive_Set_Predecessor from solicitor
Token_pass_timer_expires
Contention_timer_expires
12
Transitions From/To Joining
Floating
contention expired
Floating
Joining
got solicit_successor decided to join
failed to join
Monitoring
succeeded in joining
13
Transitions From/To Monitoring
Have_Token
token_holding expired
another ring not is_selfring
Joining
succeeded in joining
Offline
joined failed to transmit
received set_successor
received set_predecessor with greater priority
exceeded max token pass tries
Monitoring
token_pass expired
Idle
idle expired
Idle
received normal token w/ greater priority
output queues empty decided not to solicit
successor
received implicit ack
Floating
solicit_wait expired not is_selfring
another ring is_selfring
Soliciting
received request to join
14
States
Idle_timer_expires
Inring_timer_expires (Selfring)
Receive_Set_Successor
Receive_Set_Successor _Normal
_Set_Predessor
Solicit_successor_timer_expires
Solicit_wait_timer_expires
Inring_timer_expires (Not Selfring)
Receive_from_other_ring
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Transitions From/To Soliciting
solicit_wait expired not is_selfring
Monitoring
received normal token w/ greater priority
output queues empty decided to solicit successor
received request to join
Idle
solicit_successor expired
Soliciting
solicit_wait expired is_selfring
Idle
received token of higher priority
Floating
another ring is_selfring
Offline
another ring not is_selfring
16
Transitions From/To Idle
Offline
another ring not is_selfring
another ring and is_selfring
Floating
claim token expired
Floating
inring expired
received normal token with greater priority
output queue is nonempty
Have_Token
received set_successor
received set_predecessor with greater priority
Monitoring
Monitoring
Idle
idle expired
received implicit ack
received normal token w/ greater priority
output queues empty decided not to solicit
successor
solicit_successor expired
received normal token w/ greater priority
output queues empty decided to solicit successor
Soliciting
Soliciting
solicit_wait expired is_selfring
got token of greater priority
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Transition Conditions From B,F,H,J

• B_F always
• F_I claim_token timer expired
• F_J received solicit_successor packet and
  decided to join
• H_M token_holding timer expired
• J_F contention timer expired, or failed to join
• J_M succeeded in joining

18
Transition Conditions From I(1)

• I_F received packet from another ring and
  is_selfring or inring timer expired
• I_H received normal token with greater priority
  an output queue is nonempty
• I_O received packet from another ring and not
  is_selfring
• I_S received normal token with greater priority
  output queues are empty decided to solicit
  successor or solicit_successor timer expired

19
Transition Conditions From I(2),O

• I_M received set_successor or received token
  with greater priority and (token is
  set_predecessor or (token is normal output
  queues are empty and didnt decide to solicit
  successor)) or idle timer expired
• O_F offline timer expired

20
Transition Conditions From M

• M_F received packet from another ring and
  is_selfring
• M_I received implicit ack
• M_O received packet from another ring and not
  is_selfring or exceeded max token pass tries or
  just joined and failed to transmit or token_pass
  timer expired

21
Transition Conditions From S

• S_F received packet from another ring and
  is_selfring
• S_I received token of lesser priority or
  solicit_wait timer expired and is_selfring
• S_M received request to join or solicit_wait
  timer expired and not is_selfring
• S_O received packet from another ring and not
  is_selfrin

22
Simulator
INPUT File
NAM File
TRACE File
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Simulator

• Packet Loss
• Free Way Propagation Model
• Packet Corruption
• Signal to Noise Ratio (pending)

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Simulator

• Node File (input)
• Simulation time, Range, Velocity, Seed, Namfile,
  Tracefile, node, Mobility pattern, xy location.
• Nam File (output)
• Gives in NAM format
• Shows node movement,Transmission,Reception and
  Ring Address
• Trace File (output)
• Detailed information of received and sent packets
  for analysis.

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Simulator

• Mobility Patterns

Bounce
Brownian
Stable
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UDP Implementation
Tx_Handler Process Packet
Timeout
Packet from Application
SELECT
Packet from Medium
Timer_Handler
Change State
Rx_Handler
Process Packet Reset Timers
Initialize Timers
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Packet Formats
UDPApplications 2
UDPApplications 1
ltDADDR1, DPORT1gt,PACKET1
ltLOCAL, TOKAPPPORT gt, ltDADDR1, DPORT1gt PACKET1
Token Ring
TOKAPPPORT
TOKDEVPORT
NET
ltDADDR1, TOKDEVPORT gt, DPORT1 PACKET1
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User Interface

• int my_socket(int domain, int type, int protocol)
• int my_bind(int sockfd, struct sockaddr my_addr,
  socklen_t addrlen)
• int my_recvfrom(int s, void buf, size_t len, int
  flags, struct sockaddr from, socklen_t fromlen)
• int my_sendto(int s, const void msg, size_t len,
  int flags, const struct sockaddr to, socklen_t
  tolen)
• int select(int. . . .)
• Int close(int s)

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Example my_sendto

• int my_sendto(int s, const void msg, size_t len,
  int flags, const struct sockaddr to, socklen_t
  tolen)
• deviceAddr.sin_family AF_INET
• deviceAddr.sin_port htons(TOKPORT)
• deviceAddr.sin_addr.s_addr
  inet_addr("127.0.0.1")
• memcpy(newmsg, to, sockAddrSize)
• memcpy(newmsg sockAddrSize, msg, len)
• return sendto(s, newmsg, len sockAddrSize,
  flags,
• (struct sockaddr ) deviceAddr,
  sockAddrSize)

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Demo (hellohello Application)

• Uses all the functions described above.
• Processes Compete in trying to send hellohello
  packet periodically every 1 second.

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Conclusion (Design)

• Restricted the use of timers corresponding to
  each state.
• Reduced the number of states.
• Optimization.
• Further debugging.
• Simplified Parameterization.
• Minimized Memory allocation.
• Use of queues.
• Maximum use of existing kernel functions.

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Parametrization (Example)

• station-gtMAX_TOKEN_PASS_TIME upper_token_holding
  _time(station, station-gtTS) upper_proc_time(stat
  ion, station-gtTS) upper_token_holding_time(stati
  on, station-gtNS) upper_proc_time(station,
  station-gtNS)
• station-gtMAX_SOLICIT_SUCCESSOR_TIME
  upper_proc_time(station, station-gtTS)
  ((SOLICIT_SUCCESSOR_SIZE PHY_HEADER_SIZE)TICKS_
  PER_SEC / lower_transmission_rate(station))
  upper_proc_time(station, station-gtTS)
  ((SET_SUCCESSOR_SIZE PHY_HEADER_SIZE)TICKS_PER_
  SEC / lower_transmission_rate(station))
  upper_proc_time(station, station-gtTS)
  ((SET_PREDECESSOR_SIZE PHY_HEADER_SIZE)TICKS_PE
  R_SEC / lower_transmission_rate(station))

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Parameterization (Enforcement)

• ASSERT((station-gtMTRT gt station-gtMAX_TOKEN_PASS_TI
  ME))
• ASSERT(station-gtMAX_TOKEN_PASS_TIME gt
  station-gtMIN_TOKEN_PASS_TIME)
• ASSERT(station-gtMTRT gt upper_total_token_holding_
  time(station) upper_total_management_time(station
  ))

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Conclusion (Simulation Platform)

• Modeling of Channel.
• Location Information.
• Graphical Interface.
• Modeling of Device.

35
Going Forward

• Release of UDP version.
• Clean up code.
• Making more user friendly.
• Documentation.
• Kernel Implementation.
• Current code is implemented with kernel
  integration in mind.
• Need to test our assumptions of kernels (timers,
  sk_buff, flow control, hardware access
  libraries).
• Software Integration.