Nortel Networks Circuit Card - Manual (Page 327)

NT5D97 Dual-port DTI2/PRI2 card Page 327 of 906
Circuit Card Description and Installation
System capacity and performance
Physical capacity
Each NT5D97 DDP2 card occupies one slot on the network shelf. Each card
supports two digital trunk circuits and two network loops. The total number
of DDP2 cards per system is limited by the number of network loops, physical
capacity of the shelf, number of DTI2/PRI2 interfaces allowed by the
software and the range of DCH addresses.
D-Channel capacity
The software configuration for the NTBK51AA DDCH is similar to the
MSDL and only supports D-channel functionality.
The system has a total capacity of 16 addresses (Device Addresses or
DNUM) that can be reserved for DCH card, MSDL card or DDCH card. One
exception is DNUM 0 which is commonly assigned to the TTY terminal.
No two different D-Channel providers can share the same DNUM. Hence, the
combined maximum number of DCH, MSDL and DDCH cards in the system
is 16.
The DCH has one D-Channel unit, the DDCH has two D-Channel units, and
the MSDL has a maximum of four units. Therefore, the total number of
D-Channel is derived by the following formula:
Total_Num_DCH-Units = Num_DCHx1 + Num_DDCHx2 +
Num_MSDLx4
Therefore, Total_Num_DCH-Units in any given system is between 0-63.
CPU capacity
Using a NT5D97 DDP2 card instead of DTI2/PRI2 cards does not increase
the load on the CPU. The DDP2 replaces an ENET card and two DTI2/PRI2
cards. Emulating the ENET card and the overall CPU capacity is not impacted
by using a DDP2 card instead of a DTI2/PRI2 card.