User guide

26 Chapter 1. Router Concepts
MAC Encapsulated Routing: RFC 1483MER (ATM) or RFC 1490MER
(Frame Relay)
MER encapsulation allows IP packets to be carried as bridged frames, but does not prevent bridged frames from
being sent as well, in their normal encapsulation format: RFC 1483 (ATM) or RFC 1490 (Frame Relay).
If IP routing is enabled, then IP packets are prepended with the sequence 0xAAAA0300 0x80c20007 0x0000 and
sent as bridged frames. If IP routing is not enabled, then the packets appear as bridged frames.
The commands for this encapsulation option are:
remote setProtocol RFC1483MER <remoteName> (for ATM)
remote setProtocol MER (for Frame Relay)
FRF8
IP packets have prepended to them the following sequence: 0x03CC.
The command for this encapsulation option is: remote setprotocol FRF8 <remoteName>
Note: This protocol allows sending ATM over Frame Relay.
rawIP
IP packets do not have any protocol headers prepended to them; they appear as IP packets on the wire. Only IP
packets can be transported since there is no possible method to distinguish other types of packets (bridged frames
or IPX).
The command for this encapsulation option is: remote setProtocol rawIP <remoteName>
System Files
The routerÕs file system is a DOS-compatible file system. Its contents are as follows: :
SYSTEM.CNF: These are configuration files containing:
DOD Remote Router Database
SYS System Settings: name, message, authentication method, and passwords
ETH Ethernet LAN configuration settings
DHCP.DAT: DHCP files.
FILTER.DAT: Bridge filters.
KERNEL.F2K: Router system software (KERNEL.FP1 for IDSL routers).
ETH.DEF: File used by the manufacturer to set a default Ethernet configuration.
ASIC.AIC: Firmware for the xDSL modem or ATM interface.
ATM.DAT: ATM configuration file.