3Com CoreBuilder 7000, Operation Manual

Page: 211 / 264

Version 4.5 Features 211
Protocol Stack
A UDP/IP protocol stack is implemented as a simulated Ethernet network
over the communication channel described above. The small size of the
messages transmitted necessitates fragmentation and reassembly.
Fragmentation is performed on a full Ethernet frame prior to sending
over the ICP. Message information including number, length and offset is
added to each ICP message to enable reassembly.
Routing of IP packets from one Epilogue interface to another is disabled
to allow free choice of IP addresses.
Since each TFTP message must be acknowledged, use of a TFTP protocol
over the UDP/IP protocol stack ensures these two advantages:
Only one message is being reassembled at any given time.
Performance impact on the active switch is minimized.
Switching Module
Configuration
Database
Full configuration stored in the active switching module’s flash is
replicated to the redundant switching module’s flash. Configuration is
automatically synchronized either upon detection of a redundant
switching module or upon any change in the configuration.
LES and LECS in One
CoreBuilder 7000
Each switching module has a unique MAC address. When a switch-over
takes place, the new active switching module generates an ARP response
message in order to update the management station’s ARP table with its
MAC address.
Alias Names Alias names are automatically mirrored to the redundant switching
module. Manual configuration is not required.
Management
Operations
The redundant switching module is viewed by the NMS station. The NMS
is updated with the status of the redundant switching module from time
to time. Both the active and redundant switching modules can be reset
via LMA and NMS.
Upgrading the
Software
The software is downloaded to the active switch and from the active to
the redundant switch. There is no need to reset the CoreBuilder 7000 in
order to load the software to the redundant switch.