Installation guide

Making External Connections to Cisco 4000 Series Routers 4-63
Network Connection Considerations
Figure 4-14 EIA/TIA-232 Adapter Cable Connectors, Network End
EIA/TIA-449 Connections
EIA/TIA-449, which supports balanced (EIA/TIA-422) and unbalanced (EIA/TIA-423)
transmissions, is a faster (up to 2 Mbps) version of EIA/TIA-232 that provides more
functions and supports transmissions over greater distances.
The EIA/TIA-449 standard was intended to replace the EIA/TIA-232 standard, but it was
not widely adopted primarily because of the large installed base of DB-25 hardware and
because of the larger size of the 37-pin EIA/TIA-449 connectors, which limited the number
of connections possible (fewer than possible with the smaller, 25-pin EIA/TIA-232
connector).
The network end of the EIA/TIA-449 adapter cable provides a standard 37-pin D-shell
connector. (See Figure 4-15.) EIA/TIA-449 cables are available as either DTE (DB-37
plug) or DCE (DB-37 receptacle).
Figure 4-15 EIA/TIA-449 Adapter Cable Connectors, Network End
H1343a
DTE
DCE
H1344a
DTE
DCE