+=======+        New frag RuleID received
                 |       |        ~~~~~~~~~~~~~
                 | INIT  +-------+cur_W=0;clear([cur_W,Bmp_n]);
                 +=======+       |sync=0
                                 |
    Not All* & rcv_W==cur_W+---+ | +--+
      ~~~~~~~~~~~~~~~~~~~~ |   | | | (E)
      set[cur_W,Bmp_n(FCN)]|   v v v  |
                          ++===+=+=+==+=+
   +----------------------+             +--+ All-0&Full[cur_W,Bmp_n]
   |           ABORT *<---+  Rcv Window |  | ~~~~~~~~~~
   |  +-------------------+             +<-+ cur_W++;set Inact_timer;
   |  |                +->+=+=+=+=+=+===+    clear [cur_W,Bmp_n]
   |  | All-0 empty(Wn)|    | | | ^ ^
   |  | ~~~~~~~~~~~~~~ +----+ | | | |rcv_W==cur_W & sync==0;
   |  | sendACK([Wn,Bmp_n])   | | | |& Full([cur_W,Bmp_n])
   |  |                       | | | |& All* || last_miss_frag
   |  |                       | | | |~~~~~~~~~~~~~~~~~~~~~~
   |  |    All* & rcv_W==cur_W|(C)| |sendACK([cur_W,Bmp_n]);
   |  |              & sync==0| | | |cur_W++; clear([cur_W,Bmp_n])
   |  |&no_full([cur_W,Bmp_n])| |(E)|
   |  |      ~~~~~~~~~~~~~~~~ | | | |              +========+
   |  | sendACK([cur_W,Bmp_n])| | | |              | Error/ |
   |  |                       | | | |   +----+     | Abort  |
   |  |                       v v | |   |    |     +===+====+
   |  |                   +===+=+=+=+===+=+ (D)        ^
   |  |                +--+    Wait x     |  |         |
   |  | All-0 empty(Wn)+->| Missing Frags |<-+         |
   |  | ~~~~~~~~~~~~~~    +=============+=+            |
   |  | sendACK([Wn,Bmp_n])             +--------------+
   |  |                                       *ABORT
   v  v
  (A)(B)
                                   (D) All* || last_miss_frag
    (C) All* & sync>0                  & rcv_W!=cur_W & sync>0
        ~~~~~~~~~~~~                   & Full([rcv_W,Bmp_n])
        Wn=oldest[not full(W)];        ~~~~~~~~~~~~~~~~~~~~
        sendACK([Wn,Bmp_n])            Wn=oldest[not full(W)];
                                       sendACK([Wn,Bmp_n]);sync--

                             ABORT-->* Uplink Only &
                                       Inact_Timer expires
    (E) Not All* & rcv_W!=cur_W        || Attempts > MAX_ACK_REQUESTS
        ~~~~~~~~~~~~~~~~~~~~           ~~~~~~~~~~~~~~~~~~~~~
        sync++; cur_W=rcv_W;           send Abort
        set[cur_W,Bmp_n(FCN)]