Patton electronic 2710 - Manual (Page 18)

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B8ZS: Bipolar violations occur when consecutive pulses are of the
same polarity. In B8ZS, or Bipolar Eight Zero Substitution, bipolar
violations are introduced deliberately to indicate that eight zeros
have been transmitted. This special encoding is recognized by the
receiver and decoded correctly. See AT&T TR62411 Section 4.2.2
for a detailed description of B8ZS. This enables information to be
sent over a T1 connection without any constraints on the data’s
pulse density. This is the most acceptable way to accomplish 64 kb/s
on each DS0 channel.
B7ZS: This stands for Bipolar Seven Zero Substitution. Instead of
introducing bipolar violations, this method substitutes a one for a
zero in bit 7 (out of 8) of a DS0 channel when the data in that chan-
nel are all zeros. This is a special form of AMI and is compatible only
with special equipment. For most applications, AMI or B8ZS will suf-
Þce..
– DS0 Line Rate: 64kbps (default)
Options: 64kbps, 56kbps.
64kbps: Also known as Clear Channel, this takes full advantage of
the available bandwidth in a DS0 channel. Implementing it usually
requires B8ZS line coding. In certain cases, special equipment may
implement Clear Channel using AMI or B7ZS. Consult the equip-
ment manual for compatibility. Your carrier will advise you on
whether to use 64 or 56 kb/s. Campus applications may not have
such restrictions, enabling you to use 64kbps. In Unframed format,
the 24 DS0s and the framing bits are combined to provide 1.544Mb/
s for your use.
56kbps: This uses only the Þrst seven bits of the DS0, limiting the
data rate per DS0 channel to 56 kb/s. Your carrier will advise you on
whether to use 64 or 56 kb/s. This is not available when using the
Unframed format.