1. Routing Status Terence Tong Alec Woo

2. Introduction Point of the meeting  Two implementations, mh10 and Surge.  In the progress of merging  Issues that need to be discussed  Get the best out of two implementations  Release a version

3. Issues Share knowledge Issues that are unresolved  Interface  Header  Type  Level 2 Ack Useful?  Copying?  Queue vs. Traffic Policy  Evaluation

4. Brief Overview App MHSender App ParentSelectionVirtualComm GenericComm

5. Brief Overview Multihop Application  Create Packet send it to Stack MHSender  Control of originated and forwarding queues  Implements MH interface ParentSelection  Fill out destination field VirtualComm  Retransmission, Resource Sharing  No app can dominate the comm  Provide both interface of ReceiveMsg and Snoop

6. VirtualComm Motivation  Illusion that application have its own comm. Application would not affect each other  Retransmission Send Mechanism  Packet passed to VC, check if it is busy, deposit to queue, post task to send, start resend timer if send return fail  Send Done come back, see ack, start resend timer if fail, otherwise dequeue, send next

7. VirtualComm Difference  Resend Delay. It helps reduce collision  Application controls # retransmissions Control (optional)  Receive Interface Snoop + ReceiveMsg  Concurrency  Header At the end, source, link seqnum (increase with retrans)

8. Brief Overview App MHSender App ParentSelectionVirtualComm GenericComm

9. MHsender Purpose  Control of originated and forwarding queues  Implements MH interface Send Mechanism  Multihop applications deposit packet  Forward packets (after duplicate check and intercept) are deposited  Which packet (originated / forwarding) to send  Send Done, dequeue and signal

10. MHSender Difference  Two queues Control knob. Why? Break cycle, flush forward queue  Duplicate Elimination Remember last X packet in local cache Compare data seqnum + real source  Header Data seqnum, Real Source, (Multihop Type)  Zero Copy Forward packet are copy in Surge Freelist to give back ptr to comm to recycle

11. MHSender Issues  Interface  Header  Type  Level 2 Ack Useful?  Copying?  Queue vs. Traffic Policy  Evaluation

12. Brief Overview App MHSender App ParentSelectionVirtualComm GenericComm

13. ParentSelection Role  Sniff Traffic between MHSender and VC  Fill destination field Components and Role  Algorithm, RouteTable, Estimator Route update  Cycle detected, timer fired  Choose parent, broadcast route packet

14. ParentSelection Parameters  Data rate, route update rate, estimator time window, table size, link failure threshold, parent switching threshold, estimator weight function

15. ParentSelection Difference  Cycle Detection Four Mechanism, addr = local addr (Surge have this), duplicate packet elimination, TTL, isChild Surge does not forward packet from node who has hop <= current node  Choose Parent Algorithm Surge Most Reliable out of all shortest path Declare null if no node is better MinTrans, ShortestPath w/ threshold Threshold to stablize, detect link failure

16. Parent Selection Difference  BaseStation Surge rebroadcast Treat UART as parent, dump it there. Avoid congestion in basestation  Neighbor management Surge uses randomize, evict parent Choice of sent estimate (old) freq (new)  Estimator Bidirectional feedback Same algorithm, but sniff all packet, including retranmsision