21-07-0182-00-0000 ieee 802.21 media independent handover dcn: 21-07-0182-00-0000 title: transport...
Post on 18-Jan-2016
219 Views
Preview:
TRANSCRIPT
21-07-0182-00-0000
IEEE 802.21 MEDIA INDEPENDENT HANDOVER
DCN: 21-07-0182-00-0000
Title: Transport Protocol and State Machine
Date Submitted: May, 14, 2007
Presented at IEEE 802.21 session #20 in Montreal
Authors or Source(s):
David Cypher, Richard Rouil, & Nada Golmie
NIST; 100 Bureau Drive; Gaithersburg, MD 20899-8920
Abstract: This contribution asks many questions and suggests modifications to the transport protocol (MIH_NET_SAP) and the acknowledgement state machine of clause 8.2 draft D5 April 2007.
21-07-0182-00-0000
IEEE 802.21 presentation release statementsThis document has been prepared to assist the IEEE 802.21 Working Group. It is
offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.21.
The contributor is familiar with IEEE patent policy, as outlined in Section 6.3 of the IEEE-SA Standards Board Operations Manual <http://standards.ieee.org/guides/opman/sect6.html#6.3> and in Understanding Patent Issues During IEEE Standards Development http://standards.ieee.org/board/pat/guide.html>
21-07-0182-00-0000
Subjects for discussion
• The MIH_NET_SAP as currently defined in D5 April 2007• Needs work
• What is its function?• How is MIH_TP_Data.response to be implemented?
• Contains ambiguities• What is the meaning of Reliable Delivery Flag?
• Duplicates functionality• Is it repeating the reliable transport function?• Is it repeating the acknowledgement function defined in clause 8.2?
• MIH Protocol acknowledgement operation and state machines
21-07-0182-00-0000
Needs Work
• What is the MIH_NET_SAP’s function?• Is it to provide a generic service access point (SAP) for the
transmission of MIH messages?• Is it hiding the actual method of transport from the MIH?
• If so, then why
– Reason for Transport Type (L2 or L3)?– Reliable Delivery Flag
» Option of the transport type selected?– Transport Destination and Source Addresses
» Dependent on Transport Type chosen
• How is MIH_TP_Data.response to be implemented?
21-07-0182-00-0000
Contains ambiguities
• What is the meaning of Reliable Delivery Flag?• Does it indicate that the MIH is requesting a reliable
transport?• Does it indicate that the MIH is requesting a feature in the
transport type chosen?• Is the reliable delivery Flag
• Used in combination with the MIH protocol acknowledgement operation?• Mutually exclusive to the MIH protocol acknowledgement operation?• Associated with the setting of the Ack Req /Ack Rsp of the MIH protocol
acknowledgement operation?
21-07-0182-00-0000
Duplicates functionality
• Is it repeating the reliable transport function?
• Is it repeating the acknowledgement function defined in clause 8.2?
21-07-0182-00-0000
MIH command request & response (1of4)
MIH_TP_Data.request
Transport Type
SA
DA
Reliable DeliveryFlag
MIH Protocol PDU
1SADA
T-
MIH_TP_Data.confirm
Transport Type
SA
DA
Status
1SADA0
MIH_TP_Data.indication
Transport Type
SA
DA
Reliable DeliveryFlag
MIH Protocol PDU
1SADA
T-
MIH_TP_Data.response
Transport Type
SA
DA
Status
1SADA0
Version
Ack Req
Ack Rsp
SID
Opcode
AID
TransactionID
S_MIHF
D_MIHF
INIT
See D5 -8.6.3.17
INIT
RECEIVED
MIH_MN_HO_Complete RequestAID 9, Not 23
State machineMIH request Destination Node
State machineMIH request Source Node
110319XSADA
MIHF MIHF_NET_SAP MIHF_NET_SAP MIHF
Version
Ack Req
Ack Rsp
SID
Opcode
AID
TransactionID
S_MIHF
D_MIHF
See D5 -8.6.3.17
MIH_MN_HO_Complete RequestAID 9, Not 23
110319XSADA
SENDING
1 of 4
21-07-0182-00-0000
MIH command request & response (2of4)
Version
Ack Req
Ack Rsp
SID
Opcode
AID
TransactionID
S_MIHF
D_MIHF
101319XSADA
State machineMIH request Destination Node
State machineMIH request Source Node MIHF MIHF_NET_SAP MIHF_NET_SAP MIHF
MIH_TP_Data.request
Transport Type
SA
DA
Reliable DeliveryFlag
MIH Protocol PDU
1SADA
T-
MIH_TP_Data.indication
Transport Type
SA
DA
Reliable DeliveryFlag
MIH Protocol PDU
1SADA
T-
MIH_TP_Data.response
Transport Type
SA
DA
Status
1SADA0
MIH_TP_Data.confirm
Transport Type
SA
DA
Status
1SADA0
Version
Ack Req
Ack Rsp
SID
Opcode
AID
TransactionID
S_MIHF
D_MIHF
101319XSADA
**
Acknowledgement for MIH_MN_HO_Complete Request
SENT
RECEIVEDSENDING
2 of 4
Acknowledgement for MIH_MN_HO_Complete Request
21-07-0182-00-0000
MIH command request & response (3of4)
Version
Ack Req
Ack Rsp
SID
Opcode
AID
TransactionID
S_MIHF
D_MIHF
110329XSADA
See D5 -8.6.3.18
RECEIVED
contiune - P1a1
SENT
MIH_MN_HO_Complete ResponseAID 9, Not 23
RESPONDING
MIH_TP_Data.request
Transport Type
SA
DA
Reliable DeliveryFlag
MIH Protocol PDU
1SADA
T-
MIH_TP_Data.confirm
Transport Type
SA
DA
Status
1SADA0
MIH_TP_Data.indication
Transport Type
SA
DA
Reliable DeliveryFlag
MIH Protocol PDU
1SADA
T-
MIH_TP_Data.response
Transport Type
SA
DA
Status
1SADA0
SENT
Version
Ack Req
Ack Rsp
SID
Opcode
AID
TransactionID
S_MIHF
D_MIHF
110329XSADA
See D5 -8.6.3.18
MIH_MN_HO_Complete ResponseAID 9, Not 23
State machineMIH request Destination Node
State machineMIH request Source Node MIHF MIHF_NET_SAP MIHF_NET_SAP MIHF
3 of 4
21-07-0182-00-0000
MIH command request & response (4of4)
Version
Ack Req
Ack Rsp
SID
Opcode
AID
TransactionID
S_MIHF
D_MIHF
101319XSADA
**
X
Acknowledgement for MIH_MN_HO_Complete Response
INIT
Transaction timeout
State machineMIH request Destination Node
State machineMIH request Source Node MIHF MIHF_NET_SAP MIHF_NET_SAP MIHF
MIH_TP_Data.request
Transport Type
SA
DA
Reliable DeliveryFlag
MIH Protocol PDU
1SADA
T-
MIH_TP_Data.confirm
Transport Type
SA
DA
Status
1SADA0
MIH_TP_Data.indication
Transport Type
SA
DA
Reliable DeliveryFlag
MIH Protocol PDU
1SADA
T-
MIH_TP_Data.response
Transport Type
SA
DA
Status
1SADA0
Version
Ack Req
Ack Rsp
SID
Opcode
AID
TransactionID
S_MIHF
D_MIHF
101319XSADA
**
X
COMPLETED
SENT
INIT
RESPONDING
Acknowledgement for MIH_MN_HO_Complete Response
4 of 4
contiune - P1a2
21-07-0182-00-0000
MIH protocol acknowledgement operation
• There are four state machines defined• Two for the source node and two for the destination node.• Two for the request and response service and two for the
indication only service.
• Figure 24 State machine for MIH request source node• Missing transitions
• Figure 25 State machine for MIH request destination node• Missing transitions• Consistency with text
• Figure 26 State machine for MIH indication source node• Missing transitions
• Figure 27 State machine for MIH indication destination node• Missing transition
21-07-0182-00-0000
Figure 24
INIT SENDING SENT
COMPLETED
REQ available without ACK-Req set /Send REQ
REQ available with ACK-Req set /Send REQ
Recv. ACK / No action
Recv. RSP /Send ACK if ACK-Req setOtherwise no action
Transaction TimeOut /Reset
Retransmit Timeout /Send REQ
Recv. RSP /Send ACK if ACK-Req setOtherwise no action
Recv. RSP /Send ACK if ACK-Req setOtherwise no action
What happens when maximum retransmisison attempts occur?
What happens if RSP is not received?
1) Should add (Start Transaction Timer) to all transitions out of INIT 2) Should add (Start Retransmission Timer) to transition from INIT to SENDING and to the loopback transition in SENDING 3) Should add to all states, except INIT, that do not have it, a transition for the expiry of Transaction timer.
21-07-0182-00-0000
Figure 25
INIT RECEIVED RESPONDING
COMPLETED
RSP available without ACK-Req set /Send RSP
Transaction TimeOut /Reset
Recv. REQ /Send ACK if ACK-Req set and RSP not availableOtherwise no action
What happens when maximum retransmisison attempts occur?
1) Should add (Start Transaction Timer) to transition out of INIT 2) Should add (Start Retransmission Timer) to transition from RECEIVED to RESPONDING and to the loopback transition in RESPONDING 3) Should add to all states, except INIT, that do not currently have it, a transition for the expiry of Transaction timer.
Recv. REQ /Send ACK if ACK-Req set and RSP not availableOtherwise no action
Recv. REQ with ACK-Req set /Send RSP
Recv. REQ with ACK-Req set or Retransmission timeout /Send RSP
RSP available with ACK-Req set /Send RSP
Recv. ACK or Transaction TimeOut /Reset
21-07-0182-00-0000
Consistency (Figure 25 and 8.2.2.2.2)
• The third paragraph states, “ If the MIH Request message has the ACK-Req bit set and the response is immediately available, the request destination node transits to RESPONDING state via RECEVIED state by sending the MIH Response message with ACK-Rsp bit set.”
• There are two transitions out of RECEIVED and both are for sending the RSP
• If the RSP has the ACK-Req set, it goes to RESPONDING• If the RSP does not have the ACK-Req set, it goes to
COMPLETED
• Text and figure do not agree. The choice of transition out of RECEIVED is not dependant upon the ACK-Req in the received REQ, but rather the choice of the ACK-Req bit in the RSP to be sent.
21-07-0182-00-0000
Figure 26
INIT SENT
IND available without ACK-Req set /Send IND
What happens when maximum retransmisison attempts occur?
1) Should add (Start Transaction Timer) to transition out of INIT to SENT2) Should add (Start Retransmission Timer) to transition from INIT to RESPONDING and to the loopback transition in RESPONDING
IND available with ACK-Req set /Send IND
Recv. ACK or Transaction TimeOut /Reset
Retransmission TimeOut /Send IND
21-07-0182-00-0000
Figure 27
INIT RECEIVED
Transaction TimeOut /Reset
1) Should add (Start Transaction Timer) to transition out of INIT to RECEIVED
Recv. IND with ACK-Req set /Send ACKRecv. IND without ACK-Req set /
Reset
Recv. IND with ACK-Req set /Send ACK
21-07-0182-00-0000
Conclusions
• There are many issues that need answers before either the transport protocol or the MIH protocol acknowledgement state machines can be finalized and made to operate properly.
• Agreed answers to posed questions could help to guide corrections, modifications, and new text for next version of the draft.
top related