Digital or Analog Leased-Line Network Interfaces
The digital or analog leased-line network interface is provided by two 50-pin connectors (P21 and P22) on the back of the carrier. Each connector serves eight contiguous slots in the carrier: one for Slots 1± 8 and one for Slots 9 ±16.
Depending upon your configuration, use one of the following schemes for the digital/analog leased-line interfaces (Figure 3-29):
•The 50-pin cable can be attached to a
66A-punchdown block. With this scheme, the circuits must be hard-wired to the block.
•The DDS provider installs the RJ48T-type network interface that the 50-pin cable is plugged into. The RJ48T is specified to allow from 1 to 12 DDS circuits to be placed on a single 50-pin connector. Be sure to specify to the service provider that only the first eight circuit positions are used in each 50-pin connection at the carrier. Note that you cannot use a leased-line modem in this half of the carrier.
•The 50-pin cable can be plugged into a
3600-F2-503 adapter cable. This adapter cable provides 8 keyed modular connectors using Pins 1, 2, 7, and 8. These connect the DSU to a standard DDS network interface (RJ48S) and also provide the new JM8-style leased-line connection for the leased-line modem. This interconnection scheme allows mixing DSUs and leased-line modems only if the analog leased-line network interface is a JM8.
•The 50-pin cable can be attached to the
3000-F1-009 adapter cable. This is a standard DDS/leased-line connection in parts of Canada. It provides eight 6-pin modular plugs. (This interconnection scheme is not recommended for U.S. application.)
To install the digital network or analog leased-line interfaces:
.Procedure
1.Connect the network cables (50-pin mass termination line cable ± feature number
3600-F2-503) to the carrier and use the small screwdriver to engage and tighten the screw. For installation in Canada, a special network interface adapter cable is provided (feature number
3000-F1-009). First, connect the cables to the carrier and use the small screwdriver to engage and tighten the screw.
2.Attach a cable tie to the cable near the hood at the carrier's cable-tie attachment point. (If a ªstraight-inº cable is used, disconnect the cable tie, remove the screw and cable tie mount, and fasten the cable with two screws.)
3.Connect the individual cables with 8-pin modular plugs into the adapter for each DDS line.
Dial Network Interface
The direct distance dialing (DDD) network interface is provided by two optional network interface modules (NIMs) on the back of the carrier (Figure 3-28): an RJ21X (permissive) or an RJ27X (programmable) 50-pin connector. When there are two modules, they can be different types of NIMs independent of one another. Appendix A provides the pin assignments for these connectors.
Additional features available for both programmable and permissive NIMs are Service Line and Make Busy. The Service Line feature permits an extra dial line to be connected to the carrier. NIMs with this feature are identified by two Service Line modular connectors mounted on the NIM. The two Service Line connectors are connected in parallel on the NIM board and can be used in daisy chaining (sharing) a single dial line between the two halves of the carrier (Slots 1 through 8 and Slots 9 through 16) and also between multiple carriers.
