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| | RFC 1549 (rfc1549) |
 | | The Data Link Layer PPP uses the principles, terminology, and frame structure of the International Organization For Standardization's (ISO) 3309-1979 Simpson [Page 4] RFC 1549 HDLC Framing Decvember 1993 High-level Data Link Control (HDLC) frame structure [2], as modified by "Addendum 1: Start/stop transmission" [3], which specifies modifications to allow HDLC use in asynchronous environments. |
 | | Simpson [Page 5] RFC 1549 HDLC Framing Decvember 1993 Flag Sequence The Flag Sequence indicates the beginning or end of a frame, and always consists of the binary sequence 01111110 (hexadecimal 0x7e). |
 | | Simpson [Page 10] RFC 1549 HDLC Framing Decvember 1993 Aborting a Transmission A sequence of more than six "1" bits indicates an invalid frame, which is ignored, and not counted as a FCS error. |
| www.cse.ohio-state.edu /cgi-bin/rfc/rfc1549.html (3985 words) |
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