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Forwarding at Intermediate and Destination Mesh Points (MP) using 6-Address Scheme

Forwarding at Intermediate and Destination Mesh Points (MP) using 6-Address Scheme. Authors:. Date: 2007-09-12. Abstract. This submission fixes some problems of the addressing and forwarding at intermediate MP and destination MP.

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Forwarding at Intermediate and Destination Mesh Points (MP) using 6-Address Scheme

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  1. Forwarding at Intermediate and Destination Mesh Points (MP) using 6-Address Scheme Authors: Date: 2007-09-12 L.Chu Etc.

  2. Abstract This submission fixes some problems of the addressing and forwarding at intermediate MP and destination MP. L.Chu Etc.

  3. The current draft loses the scenario that the destination MP is the final destination when the extension mode is 10. In the current draft, if the current MP is the Root of the HWMP routing tree and if the DA in Address 5 corresponds to an MP, the MP shall reformat the frame as a 4-address frame. The 4-address frame may lose the source MP address. The source MP address is needed for checking the sequence number in order to discard duplicates and resequence the reordering frames. Non-QOS MP will lose TID information when forwarding a frame. This may break QOS requirement. The processing of multihop action frames is missing. Addressing and forwarding at the source MP includes the processing of multihop action frames. Problems with Current Intermediate and Destination MP Forwarding in .11s Draft L.Chu Etc.

  4. The Destination MP is the Destination, and not a Proxy for the Destination Wired L2 Network STA1 (MPP1)Root Mesh Network MAP1 MPP2 MP2 MP2 MP4 MAP1 MAP3 MAP2 MPP2 The MPP finds that address 5 is its MAC address, indicating this MP is the final destination. So the MPP shall process and send to an upper layer. (The text provided needs to be added to the draft, but currently this case is not addressed) STA1 L.Chu Etc.

  5. Wired L2 Network (MPP1)Root Mesh Network MPP2 MP2 MP4 MAP1 MAP3 MAP2 STA1 Losing Source MP Information when Changing Address Scheme at a Root STA1 MAP1 MP2 Root MPP2 4-address frames lose source MP (MAP1) information. Frame forwarding using the forwarding procedure defined in the current 802.11s draft. L.Chu Etc.

  6. MAP1 has sequence number x. When MAP1 receives 3 frames from STA1 for the Root, it uses 6-address scheme with mesh sequence number x, x+1, x+2 to send them to MPP2 through the Root. The Root forwards these frames using 4-address scheme. Root Problem with Changing Address Scheme at Root STA1 Wired L2 Network MAP1 (MPP1)Root Mesh Network MP2 MPP2 MP2 MP4 MAP1 MAP3 MAP2 MPP2 STA1 Frame forwarding using the forwarding procedure defined in the current 802.11s draft. L.Chu Etc.

  7. Then STA1 roams and associates with MAP2. MAP2 also has sequence number x. When MAP2 receives the following 3 frames from STA1 for the Root, it uses 6-address scheme with mesh sequence number x, x+1, x+2 to send them to MPP2 through the Root. Root Problem with Changing Address Scheme at Root (cont’d) Wired L2 Network STA1 (MPP1)Root MAP2 Mesh Network MPP2 MP2 MP2 MP4 MAP1 MAP3 MAP2 MPP2 STA1 Frame forwarding using the forwarding procedure defined in the current 802.11s draft. L.Chu Etc.

  8. If MPP2 receives these 6 frames in the following sequence: MAP1-x (frame x forwarded by MAP1), MAP2-x, MAP2-x+1, MAP1-x+1, MAP1-x+2, MAP2-x+2, MAP2-x, MAP1-x+1, MAP2-x+2 will be discarded. The reason is that the source MP information is lost! If MPP2 receives these 6 frames in the following sequence: MAP1-x (frame x forwarded by MAP1), MAP1-x+1, MAP1-x+2, MAP2-x, MAP2-x+1, MAP2-x+2, MAP2-x, MAP2-x+1, MAP2-x+2 will be discarded. The reason is that the source MP information is lost! Problem with Changing Address Scheme at Root (cont’d) L.Chu Etc.

  9. Supposing that the following frame forwarding occurs QMP1 sends frame x, x+1, x+3, x+8 with TID 0 to QMP3. QMP1 sends frame x+2, x+4, x+5 with TID 6 to QMP5. QMP1 sends frame x+6, x+7, x+9 with TID 6 to MP3. After nQMP2’s forwarding, the frames to QMP3 lose TID information QMP3 receives frames x, x+6, x+1, x+7, x+8, x+3, x+9 with TID 0. Problems with current frame format It is difficult for MP3 to send frames in order to its upper layer. nQMP2 loses TID information. It is difficult to guarantee QOS requirement. Path with Non-QOS MP as Forwarding MP nQMP4 2 2 Link metric c 1 1 c MPy MPx QMP7 QMP6 Forwarding path QMP3 QMP1 1 2 nQMP: non-QOS MP 1 QMP: QOS MP nQMP2 QMP5 Frame forwarding using the mesh frame format defined in the current 802.11s draft L.Chu Etc.

  10. A TID subfield field is added to the mesh flag subfield. Source QOS MPs copy UP to TID subfield in mesh flag field. Source non-QOS MPs set TID subfield in mesh flag field to 0. After a QOS MP which is not the destination MP (proxy MP or final destination) receives a frame, It shall use TID in Mesh flag field the same as MA-UNITDATA primitives to create MPDU. After a destination MP receives a frame, It shall create MSDU and copy TID in Mesh flag field to UP in MA-UNITDATA.indication primitive. Implementing End to End TID Forwarding Mesh Header Sequence Number Mesh TTL Mesh Flag Mesh Address Extension DATA Address Extension Mode Reserved TID B0 B1 B2 B4 B5 B7 The new mesh header with TID being added L.Chu Etc.

  11. If the Address Extension Mode is set to 00 or 01, indicating this MP is the final destination of the frame, the MP shall process and send it to an upper layer. By the pair of source MP Address (identified by Address 4 field) and Mesh Sequence Number, the destination MP may detect duplicate frames. Duplicate frames shall be discarded if detected. If the Address Extension Mode is set to 10 or 11: If the Address 5 is the same as the current MP’s MAC address, the MP shall process and send it to an upper layer. By the pair of source MP Address (identified by Address 4 field) and Mesh Sequence Number, the destination MP may detect duplicate frames. Duplicate frames shall be discarded if being detected. Updated Intermediate/Destination MP Forwarding L.Chu Etc.

  12. If the current MP is a proxy MP for non-mesh, proxied entities, the MP shall first check whether or not the destination address (DA) in Address 5 field is one of the addresses of its proxied entities. If the destination address is the address of one of its proxied entities, the MP shall translate the frame to the corresponding format and queue it for transmission to the final destination. By the pair of source MP Address (identified by Address 4 field) and Mesh Sequence Number, the destination MP may detect duplicate frames. Duplicate frames shall be discarded if being detected. Updated Intermediate/Destination MP Forwarding L.Chu Etc.

  13. If the current MP is a root MP (in HWMP proactive tree building mode), the MP shall check whether the DA in Address 5 field is one of its known addresses or not: If the DA in Address 5 corresponds to an MP and Address 4 is the same as Address 6, the MP shall reformat the frame as a 4- address frame with Address 3 field set to the DA, Address 4 set to the source end-point address, Address 1 set to the next-hop MP on the mesh path to the destination MP, and Address 2 set to the root MP’s address. The MP shall then queue the frame for transmission. If the DA in Address 5 corresponds to an MP and Address 4 is not the same as Address 6, the MP shall set the Address 3 field to the DA, Address 1 set to the next-hop MP on the mesh path to the destination MP, and Address 2 set to the root MP’s address. The MP shall then queue the frame for transmission. If the DA in Address 5 corresponds to a non-mesh entity proxied by one of its known MPs, the MP shall update the Address 3 field to the address of the proxy MP, the Address 1 field to the next-hop MP on the mesh path to the proxy MP, and Address 2 to the root MP’s address. The MP shall then queue the frame for transmission. Updated Intermediate/Destination MP Forwarding L.Chu Etc.

  14. Frame forwarding Using Updated forwarding procedure Wired L2 Network New Frames Forwarding At Root with DA being a MP STA1 MAP1 MP2 Root (MPP1)Root Mesh Network MPP2 MPP2 Root uses 6-address scheme since Address 4 is not the same as Address 6. No source MP information (i.e. source MP address and source MP sequence number) is lost. MP2 MP4 MAP1 MAP3 MAP2 STA1 L.Chu Etc.

  15. Frame forwarding Using Updated forwarding procedure Wired L2 Network New Frames Forwarding At Root with DA being a MP MPP3 MP2 Root (MPP1)Root Mesh Network MPP2 MPP2 Root uses 4-address scheme since Address 4 is the same as Address 6. No source MP information is lost, because the mesh SA = SA. MP2 MP4 MAP1 MAP3 MAP2 L.Chu Etc.

  16. Backup Slides L.Chu Etc.

  17. Valid Address Fields for Mesh Data and Multihop Action Frames RA=Receiver’s Address TA=Transmitter’s Address DA =Destination Address SA=Source Address Mesh Header Sequence Number Mesh TTL Mesh Flag Mesh Address Extension DATA Reserved Address Extension Mode B2 B1 B7 B0 L.Chu Etc.

  18. Current Forwarding of Unicast Frames At Intermediate and Destination MP in .11s Draft • If the Address Extension Mode is set to 00, indicating this MP is the final destination of the frame, the MP shall process and send it to an upper layer. By the pair of source MP Address (identified by Address 4 field) and Mesh Sequence Number, the destination MP may detect duplicate frames. Duplicate frames may be discarded. • If the Address Extension Mode is set to 10: • If the current MP is a proxy MP for non-mesh, proxied entities, the MP shall first check whether or not the destination address (DA) in Address 5 field is one of the addresses of its proxied entities. If the destination address is the address of one of its proxied entities, the MP shall translate the frame to the corresponding format and queue it for transmission to the final destination. • If the current MP is a root MP (in HWMP proactive tree building mode), the MP shall check whether the DA in Address 5 field is one of its known addresses or not: • If the DA in Address 5 corresponds to an MP, the MP shall reformat the frame as a 4- address frame with Address 3 field set to the DA, Address 4 set to the source end-point address, Address 1 set to the next-hop MP on the mesh path to the destination MP, and Address 2 set to the root MP’s address. The MP shall then queue the frame for transmission. • If the DA in Address 5 corresponds to a non-mesh entity proxied by one of its known MPs, the MP shall update the Address 3 field to the address of the proxy MP, the Address 1 field to the next-hop MP on the mesh path to the proxy MP, and Address 2 to the root MP’s address. The MP shall then queue the frame for transmission. L.Chu Etc.

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