Nortel Networks 553-3001-211 manual 758 of 894 NTBK22 Misp card

Page 758 of 894 NTBK22 MISP card

Refer to ISDN Basic Rate Interface: Installation and Configuration

(553-3001-218) and ISDN Basic Rate Interface: Features (553-3001-380) for additional information.

Functional description

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 supports only 31 DSLs.

The main functions of the MISP are:

•communicate with the Call Server CPU to report ISDN BRI status and receive downloaded application software and configuration parameters

•manage Layer 2 and Layer 3 signaling that controls call connection and terminal identification

•control terminal initialization and addressing

•assign B-channels for switched voice and data transmission by communicating with the BRI terminal over the D-channel and allocating to it an idle B-channel with appropriate bearer capabilities

•separate D-channel data from signaling information and route the data to the packet handler

•send call control messages to ISDN BRI terminals over the D-channel

Micro Processing Unit (MPU)

The MPU coordinates and controls data transfer and addressing of the peripheral devices and communicates with the CPU using a message channel on the CPU bus. The tasks that the MPU performs depend on the interrupts it receives. The interrupts are prioritized by the importance of the tasks they control.

553-3001-211 Standard 2.00 September 2004