Chapter3 Create Connection Wiza rds
Configure Clock Settings
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Cisco Router and Security Device Manager Version 2.2 User’s Guide
OL-4015-08
T1 Framing
This field configures the T1 or E1 link for operation with D4 Super Frame (sf) or
Extended Superframe (esf). The default is esf.
Line Code
This field configures the router for operation on binary 8-zeroes substitution
(B8ZS) or alternate mark inversion (AMI) T1 lines. The b8zs setting ensures
density on a T1 or E1 line by substituting intentional bipolar violations in bit
positions 4 and 7 for a sequence of eight zero bits. When the router is configured
with the ami setting, you must guarantee density in your router c onfiguration with
the data-coding inverted setting. The default is b8zs.
Data Coding
Click inverted if you know that user data is inverted on this link, or if Line Code
is set to AMI. Otherwise leave this set to the default value normal. Data inversion
is used with bit-oriented protocols such as HDLC, PPP, and Link Access
Procedure, Balanced (LAPB) to ensure density on a T1 line with AMI encoding.
These bit-oriented protocols perform zero insertions after every five “one” bits in
the data stream. This has the effect of ensuring at least one zero in every eight bits.
If the data stream is then inverted, it ensures that at least one out of every eight
bits is a one.
If you do not want to use inverted data coding with the AMI line code, you must
use the CLI to configure all time slots to 56 kbps. SDM will set data coding to
inverted if the line code is AMI and there are no time slots configured for 56 kbps.
Facilities Data Link (FDL)
This field configures the router behavior on the Facilities Data Link (FDL) of the
Extended Superframe. When configured with att, the router implements AT&T
TR 54016. When configured with ansi, it implements ANSI T1.403. When you
choose both, the router implements both att and ansi choices.When you choose
none, the router ignores the FDL. The default is none. If T1 or E1 framing is set
to sf, SDM will set FDL to none and make this field read-only.