Rfc1294 Multiprotocol Encapsulation - Motorola 110502USM001 - Vanguard 60 Router User Manual

WAN Adapter

RFC1294 Multiprotocol Encapsulation

Overview
How the WAN
Adaptor Handles
RFC 1294
Packet Format
Note: The RFC1204 encapsulation to a
2-8
RFC1294 encapsulation is used for the IP and RIP protocols. RFC1490 extends
RFC1294 to handle SNA protocols. For IP and IPX, however, RFC1294 and
RFC1490 are identical. All protocols are encapsulated using the NLPID format for IP.
The WAN adapter handles RFC1294 encapsulation as follows:
1) The WAN Adapter creates an RFC1294 header and places it in the packet in
front of the data before the packet is passed to the WAN protocol stack.
2) The RFC1294 header is passed as data by the WAN protocol stack and is
processed and stripped from the packet by the receiving WAN Adapter.
3) The packet is passed to the Routing forwarder.
Note
The Vanguard does not support the RFC1294 encapsulation of bridge data.
If a WAN Adapter LAN Connection record has the parameter LAN Forwarder
Type of BRID or BROUT, then the Encapsulation Type must be CODEX
(not RFC1294); otherwise, bridge data will be lost. If bridge traffic will be sent
over an FRI port, then the encapsulated bridge traffic can be sent over an Annex
G station on the port.
Figure 2-3 shows the two main WAN packet formats in use for Frame Relay
connections.
RFC1294 Encapsulation
Bypass Station
Flag
Q9.22
Q9.22
NPLID
Protocol
Packet
CRC
CRC
Flag
Bypass FR station is used for
interoperability with non-Motorola
routers.
Figure 2-3. Packet Formats
Codex Encapsulation
Annex G Station
Flag
Q9.22
Q9.22
OxCC
ADDR
CTL
LGN
LCN
CTL
Protocol
Packet
Type=0
Flags
CRC
CRC
Flag
Note: Motorola to Motorola links are recommended to use
Codex encapsulation over Annex G-type Frame
Relay stations.
LAPB Header
X25 Packet Header
Codex Trailer
Vanguard Routing Model