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Chapter 1
Overview
Caution
Cisco assumes no responsibility for system operation with other than Cisco-supplied
adapter cables. The customer is responsible for ensuring that any customer-built cables
meet all of the applicable compliance requirements (see the
section on page
T3 systems are designed for cable lengths of 450 feet (137 meters) between the transmitter and the
DSX-3 demarcation point where the standard pulse mask must be met. From the DSX-3 point, another
run of 450 feet (137 meters) is allowed to the receiver, making a total of 900 feet (274 meters) between
transmitter and receiver. This limitation is due to signal attenuation in the cable.
Although the American National Standards Institute (ANSI) standard T1.404-1994 stipulates the
Western Electric or equivalent 728A SMB cable, it has been replaced by the Lucent (formerly AT&T)
734A cable. Cisco tested more than 900 feet (274 meters) of 734A SMB cable from transmitter to
receiver including the SMB-to-BNC adapter cables to verify high signal attenuation.
Table 1-4
attenuation. RG-179 has a much higher attenuation, so take this information into account if you plan long
runs of RG-179 cable.
Table 1-4
Approximate Cable Attenuation, dB
Frequency
1 MHz
10 MHz
50 MHz
100 MHz
1. dB = decibels
Management Information Base
Management Information Base (MIB) attributes are readable and writable across Integrated Local
Management Interface (ILMI) through use of the Simple Network Management Protocol (SNMP).
The 6-port 6T3 line card supports the DS3 interface MIB (RFC 1407).
Line Card Slot Locations on the Supported Platform
This section discusses line card slot locations on the supported platform. The illustration that follows
summarizes slot location conventions on the Cisco 7304 router:
•
OL-3449-02
viii).
lists some approximate attenuation values from the ANSI standard, and shows the RG-179
ANSI Standard Cable-Attenuation Values
100 ft (30 meters)
0.27
0.80
1.82
2.64
Cisco 7304 Router Slot Numbering, page 1-8
"Related Documentation"
1
from ANSI Standard T1.404-1994
Transmitter-to-receiver
DSX-3 Point
distance (max)
450 ft (137 meters)
900 ft (274 meters)
1.2
2.4
3.6
7.2
8.2
16.4
11.9
23.8
Clear Channel 6-Port T3 (DS3) Line Card Installation and Configuration
Management Information Base
RG-179
100 ft (30 meters)
3.0
5.3
8.5
10.0
1-7
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