Ntbk22 Multi-Purpose Isdn Signaling Processor; (Misp) Card; Nt6D70Aa/Nt6D70Ba S/T Interface Line Card (Silc) - Nortel Meridian 1 Administration And Maintenance

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NTBK22 Multi-Purpose ISDN Signaling Processor (MISP) card

NT6D70AA/NT6D70BA S/T Interface Line card (SILC)

553-3011-311 Standard 7.0
Chapter 5 — ISDN BRI line and packet data implementation
The MISP card (NTBK22) is an Option 11 specific card (Options 21 through
71 use the NT6D73AA). It performs Data Link (Layer 2) and Network (Layer
3) processing associated with the OSI protocol.
Each MISP can support 4 line cards (UILC or SILC or any combination of the
two). Each line card supports 8 DSLs, therefore each MISP supports 32
DSLs. Since each DSL uses two B-channels and one D-channel the MISP
supports 64 B-channels and 32 D-channels. If the MISP is carrying packet
data, it must dedicate one of its D-channels to communicate with the external
packet handler. In this case the MISP support only 31 DSLs. The MISP
supports the downloading of ISDN applications from the Option 11 software
cartridge. The MISP will be downloaded with the appropriate application
code:
— on the first enabling of the MISP card
— when Option 11 Software is upgraded
— when MISP Applications are added/changed
The applications for the MISP are copied from the software cartridge into
RAM on the MISP card. Only the new/different applications are downloaded.
This information is then copied into the Flash ROM on the MISP for storage.
This process requires approximately 10 minutes to complete and is carried out
while the MISP pack is operational. The next time the system or MISP card
resets, the application is loaded from the MISP Flash ROM provided there are
no new or different applications on the software cartridge.
Use the equation below to calculate the number of MISPs required to control
SILCs and UILCs.
(SILCs + UILCs) ÷ 4 = MISPs
If the result is a fraction, round it off to the next highest number.
The Option 11 SILC cards (NT6D70AA -48V North America, NT6D70BA
-40 V International) are the same circuit cards used by the rest of the Meridian
1 product line. The SILC is a globally accepted standard interface. The SILC
circuit cards support the OSI physical layer (layer 1) protocol.
May 1999