Codex Proprietary Encapsulation - Motorola 110502USM001 - Vanguard 60 Router User Manual

Codex Proprietary Encapsulation

Overview
Two-Byte Message
Trailer
Vanguard Routing Model
T0100-01, Revision B
The WAN Adapter handles Codex Proprietary encapsulation as follows:
• The WAN Adapter places a 2-byte message trailer in the packet before the
packet is passed to the WAN protocol stack.
• This 2-byte trailer is passed as data by the WAN Adapter stack and is
processed and stripped from the packet by the receiving WAN Adapter.
• The packet is passed to the router or bridge forwarder.
This 2-byte field is used as follows:
• Byte 1: Indicates the protocol type of the LAN forwarder, such as SR, STPE,
and IP. The key Protocol IDs are: IP=00, IPX = 07, Motorola Codex SR=64,
Motorola Codex STPE=65, and Motorola Codex TB=66.
• Byte 2: Indicates other packet-specific information. This byte contains
information that is copied from the Control field portion of the Application
field of the packet header. For example, bits in this field indicate whether the
frame's CRC is present.
WAN Adapter
2-7
Release 5.4