NOTE: BITS input is a T1/E1 line interface unit (LIU), with AMI (alternate mark
inversion) encoding enabled and B8ZS/HDB3 (Zero Suppression) disabled.
The equalization is set for a 0-133 feet cable. An internal 100 ohm termination
is present, although it might need to be externally augmented based on the
type of cabling used. Any valid AMI signal works properly and it is not restricted
to only the "all 1" BITS signal but the ones density must be sufficient to prevent
LOS (according to the ITU G.775 recommendation). The TTL input has a slice
point of 3.3V/2 = 1.65V relative to chassis ground (GND). Therefore, any signal
on the coaxial center conductor that transitions through that voltage registers
a transition. There are many signals, besides TTL, that satisfy this criteria. An
external termination must be provided that matches the impedance of the
cable that goes to the BNC connector.
If you can configure the rate in CTP menu, then the TTL supports a frequency
of 2048 KHz for the TTL clock input, provided the signal is good and noise-free
(terminated properly). TTL is rate-agile, while BITS is restricted to T1/E1
frequencies.
The TTL input is high-impedance (no on-board termination provided) because
a variety of cable types might exist that you can use to drive signal to this
connector, such as RG-58 coax (50 ohm), RG-59 coax (75 ohm), or twisted
pair (100-120 ohm). Instead of applying a particular impedance termination
on the board and have it incorrectly done, we recommend that you configure
the impedance termination based on your network environment. For example,
a 50 ohm termination is needed if you are using RG-58/U coax cable, which
has 50 ohm impedance.
Table 28: CTP Bundle T1/E1 Port Parameter Settings in the CTP Menu
Your ActionFunctionField
Enter a description of up to 64
alphanumeric characters. Do not use the
following characters:
( ; ' " ) ]
Specifies a description for the port.Port descriptor
Select one:
•
T1
•
E1
•
Fractional T1
•
Fractional E1
Specifies the type of interface.Type
Select one:
•
B8ZS
•
AMI
Specifies the T1 encoding method used
on this bundle.
Option (for T1)
Copyright © 2018, Juniper Networks, Inc.70
Using Bundles to Create Logical Configurations for Physical Interfaces, CTP Release 7.3, CTPView Release 7.3
To Next Page
Loading...
Need help?
General
