A Layer 2 Tunneling Protocol (L2TP) performs a sender initiated recovery algorithm (SIRA) upon receiving, from an L2TP receiver, a predefined number of packets including the same “next received” (Nr) sequence number. The L2TP sender transmits a payload message that includes the “Reset Sr” (R-bit)...http://www.google.de/patents/US7085273?utm_source=gb-gplus-sharePatent US7085273 - Sender-initiated recovery algorithm (SIRA) for the layer 2 tunneling protocol (L2TP)
