The timer recovery condition is only cleared if the data link layer entity receives a valid supervisory frame response with the F bit set to "1". If the N(R) of this received supervisory frame is within the range from its current state variable V(A) to its current send state variable V(S) inclusive, it shall set its send state variable V(S) to the value of the received N(R). Timer T200 shall be reset if the received supervisory frame response is an RR or REJ response with F bit set to "1". The data link layer entity shall then resume with I frame transmission or retransmission, as appropriate. Timer T200 shall be set if the received supervisory response is an RNR response, and the data link layer shall proceed with the enquiry process in accordance with subclause 5.5.5.

hi sylvain, you are right. in case of an RR "response" (or an I frame) with the F bit set to "1", there is no clearing of the "timer recovery state". in other cases (RNR, REJ) it is handled. i would like to test this with a prepared frame drop tonight. if this works, i will commit it. regards, andreas