Nortel 5782 用户指南
Using the Model 5782 ATM Virtual Network Router
1-16
119557-A Rev. 00
Figure 1-7.
Reset Button on the Model 5782 VNR
Virtual Buffer Memory
One megabyte (MB) of virtual buffer memory (VBM) resides on the Model 5782
baseboard. The VBM module provides buffer memory in the form of static
random access memory (SRAM) to the router. A standard 5 MB VBM module
provides a total of 6 MB for the device. The VBM module attaches to the router
baseboard.
baseboard. The VBM module provides buffer memory in the form of static
random access memory (SRAM) to the router. A standard 5 MB VBM module
provides a total of 6 MB for the device. The VBM module attaches to the router
baseboard.
Segmentation and Reassembly of Packet Data
Segmentation and reassembly operate at the ATM adaptation layer (AAL) by
mapping user information into cell payloads (48 bytes of a 53-byte cell).
mapping user information into cell payloads (48 bytes of a 53-byte cell).
When the Model 5782 VNR is installed in the Model 5000BH chassis, the VNR
handles segmentation and reassembly of incoming packets to ATM cells and
outgoing ATM cells to packets.
handles segmentation and reassembly of incoming packets to ATM cells and
outgoing ATM cells to packets.
Caution:
Pressing the Reset button on a router module resets the chassis slot
in which the router is installed and temporarily suspends routing activities.
Reset button
6785
Reset