Paradyne Jetstream CPX-1000 - Manual (Page 44)

2. CPX-1000 Voice Services Platform Description 1000-A2-GN22-00
2-20 February 2003
PSTN Modules
The CPX provides complete support of the GR-303 protocol,
including full GR-303 line concentration, all CLASS and calling
features, full EOC, TMC, and path protection switching.
The CPX supports eight T1 interface groups (IGs). Each T1 port is
independently assigned to an interface group, and each interface
group supports up to 28 T1 ports. The CPX also supports path
protection switching for the control channels in the GR-303
interface group.
T1 Load Sharing
T1 load sharing is implemented by designing in excess capacity.
Overcapacity protection means the capacity of the T1 interface is
maintained when one of the following failures occurs even at the
busy hour call volume:
T1 module failure—oversize the capacity of the T1
interface for a fully operational system (
Figure 2–9A ) so that
the interface can still handle the busy hour call volume even
when one of the T1 modules has failed (
Figure 2–9B ).
T1 port failure—interface groups comprise T1 ports and
are arranged across T1 modules so that IGs are shared
among T1 modules (
Figure 2–10 ). The shared arrangement
provides a backup T1 port to each T1 module should one of
the IG groups fail.
The illustrations below show how to implement primary and
secondary module pairs, and group the T1 ports in Interface
Groups across the cards, using Octal T1 cards for clarity.
When implementing PSTN using 12-port T1 ECAC modules, you
attach the RJ-21X cable from each 12-port T1 card to a patch panel
to split out each T1 port separately for connection as usual. T1
modules are paired as primary and secondary modules, and group
the T1 ports into Interface Groups across cards in the same manner.
Caution
Do not put primary and secondary DS1 links on the same T1
module. Doing so prevents new calls from being made if
one T1 module fails.