pppdump - convert PPP record file to readable format
pppdump [ -h | -p [ -d ]] [ -r ] [ -a
  ] [ -m mru ] [ file ... ]
The pppdump utility converts the files written using the record
  option of pppd into a human-readable format. If one or more filenames
  are specified, pppdump will read each in turn; otherwise it will read
  its standard input. In each case the result is written to standard output.
The options are as follows:
  - -h
- Prints the bytes sent and received in hexadecimal. If neither this option
      nor the -p option is specified, the bytes are printed as the
      characters themselves, with non-printing and non-ASCII characters printed
      as escape sequences.
- -p
- Collects the bytes sent and received into PPP packets, interpreting the
      async HDLC framing and escape characters and checking the FCS (frame check
      sequence) of each packet. The packets are printed as hex values and as
      characters (non-printable characters are printed as `.').
- -d
- With the -p option, this option causes pppdump to decompress
      packets which have been compressed with the BSD-Compress or Deflate
      methods.
- -r
- Reverses the direction indicators, so that `sent' is printed for bytes or
      packets received, and `rcvd' is printed for bytes or packets sent.
- -a
- Prints absolute times.
- -m mru
- Use mru as the MRU (maximum receive unit) for both directions of
      the link when checking for over-length PPP packets (with the -p
      option).