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Frame Addressing and Forwarding in a Mesh. General Frame Format. Example of a Multihop Path Through a Mesh Network. Use of Mesh Address Extension Field. Processing at an MP. If an MP receives frame and it is not the Mesh DA, then
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Processing at an MP • If an MP receives frame and it is not the Mesh DA, then • If Mesh DA is known, MP forwards the frame to next MP based on forwarding information • If Mesh DA is not known, the MP may • Discard the frame, or • Trigger a path discovery
Processing at an MP • If an MP receives frame and it is the Mesh DA, and AE=00 or 01, then • It is the final destination and the frame is sent to the upper layer
Processing at an MP • If an MP receives frame and it is the Mesh DA, and AE=10 or 11, then • If it is the final destination (Mesh DA=DA), the frame is sent to the upper layer • If it is a proxy MP, the MP first checks whether DA is one of its proxied entities. If yes, it forwards the frame to the proxied DA • Otherwise…
Processing at an MP • If it is a root MP, then it checks whether the DA is one of its known addresses • Note: a known address is an address that corresponds to either an MP for which there is active forwarding information, or a non-mesh proxied STA that is known to the root MP • If DA corresponds to an MP, then it forwards it on the path from the root MP to the destination MP • Note: If Mesh SA = SA, frame is reformatted as a 4-address frame • If DA corresponds to a non-mesh entity proxied by an MP for which there is active forwarding information, then it is forwarded to the proxy MP
Detecting Duplicate Frames • Using Mesh SA and Mesh Sequence Number, duplicate frames may be detected and may be discarded