Nortel DMS-100 Series Maintenance Manual page 131

Nailed-up cross-connections
Nailed-up connections support the following special services features:
maintenance and table control for nailed-up specials on SMS
SMS special services
digital dataphone service (DDS) hairpin
direct inward dial (DID) PBX by hairpin
integrated local specials
One endpoint of the nailed-up connection must terminate on a switch that
supports these special services. This action provides support for
applications like foreign exchange and off-premises extension.
Table control for nailed-up specials on SMS This feature
implements CC code to support nailed-up peripheral-side to peripheral-side
(P-side to P-side) cross-connections on any DS-1 links located on the same
SMS.
Special services feature The special services feature implements
peripheral processor code to support nailed-up P-side to P-side
cross-connections on any DS-1 links located on the same RCS.
This feature also provides and maintains connections between pairs of P-side
channels, lines, or a combination of lines and channels on an SMS. This
action occurs in response to a CC request. These connections remain until
the CC sends a message to disconnect the connections.
Connections for special services are as follows:
line to line
DS-0 to DS-0
line to DS-0 or DS-0 to line
Digital dataphone service (DDS) hairpin feature The Digital
dataphone service (DDS) hairpin feature supports 2.4, 4.8 and 9.6 Kb/s data
cards. These cards, which transfer data over DS-1 links, employ a nailed-up
cross-connection that the DMS switch sets up. A normal data path appears
in the following Dataport cross–connection figure.
The 2.4, 4.8, and 9.6 data cards are used for data transmission only. For an
NT channel bank, these data cards work with an associated card. For
example, the D4DP20 card works with the QPP550 card.
Note: The 56 kilobit/second DDS card (D4DP70) is not supported now.
DMS-100 Family SMS Maintenance Manual XPM10 and up
SMS signaling 3-15