+The following fields are printed on the input side when the
+.B \-z
+option is not used:
+.TP
+.B IN
+The total number of bytes received by this interface.
+.TP
+.B PACK
+The total number of packets received by this interface.
+.TP
+.B VJCOMP
+The number of header-compressed TCP packets received by this interface.
+.TP
+.B VJUNC
+The number of header-uncompressed TCP packets received by this
+interface. Not reported when the
+.B \-r
+option is specified.
+.TP
+.B VJERR
+The number of corrupted or bogus header-compressed TCP packets
+received by this interface. Not reported when the
+.B \-r
+option is specified.
+.TP
+.B VJTOSS
+The number of VJ header-compressed TCP packets dropped on reception by
+this interface because of preceding errors. Only reported when the
+.B \-v
+option is specified.
+.TP
+.B NON-VJ
+The total number of non-TCP packets received by this interface. Only
+reported when the
+.B \-v
+option is specified.
+.TP
+.B RATIO
+The compression ratio achieved for received packets by the
+packet compression scheme in use, defined as the uncompressed size
+divided by the compressed size.
+Only reported when the
+.B \-r
+option is specified.
+.TP
+.B UBYTE
+The total number of bytes received, after decompression of compressed
+packets. Only reported when the
+.B \-r
+option is specified.
+.PP
+The following fields are printed on the output side:
+.TP
+.B OUT
+The total number of bytes transmitted from this interface.
+.TP
+.B PACK
+The total number of packets transmitted from this interface.
+.TP
+.B VJCOMP
+The number of TCP packets transmitted from this interface with
+VJ-compressed TCP headers.
+.TP
+.B VJUNC
+The number of TCP packets transmitted from this interface with
+VJ-uncompressed TCP headers.
+Not reported when the
+.B \-r
+option is specified.
+.TP
+.B NON-VJ
+The total number of non-TCP packets transmitted from this interface.
+Not reported when the
+.B \-r
+option is specified.
+.TP
+.B VJSRCH
+The number of searches for the cached header entry for a VJ header
+compressed TCP packet. Only reported when the
+.B \-v
+option is specified.
+.TP
+.B VJMISS
+The number of failed searches for the cached header entry for a
+VJ header compressed TCP packet. Only reported when the
+.B \-v
+option is specified.
+.TP
+.B RATIO
+The compression ratio achieved for transmitted packets by the
+packet compression scheme in use, defined as the size
+before compression divided by the compressed size.
+Only reported when the
+.B \-r
+option is specified.
+.TP
+.B UBYTE
+The total number of bytes to be transmitted, before packet compression
+is applied. Only reported when the
+.B \-r
+option is specified.
+.PP
+When the
+.B \-z
+option is specified,