HP 200 Series Services And Applications page 70

Bridging Service
Token Ring Solutions
Tunneling Direction:
SRT bridge tunnel packet:
Tunnel Header:
Tunneling Direction:
SRT bridge tunnel packet:
Tunnel Header:
Figure 10. Encapsulation Used to Tunnel Bridge Packets
Limitation
backbone, packets may only traverse HP routers functioning as SRT
bridges. Only HP routers and Wellfleet routers understand the tunneling
encapsulation.
2-18
Ethernet Token Ring
Tunnel Header Ethernet Header
Destination Station Address (48 bits):
Source Station Address (48 bits):
DSAP (8 bits):
SSAP (8 bits):
Control (8 bits):
MSID (24 bits):
Type (16 bits):
Token Ring Ethernet
Tunnel Header Token Ring Header
Destination Station Address (48 bits):
Source Station Address (48 bits):
DSAP (8 bits):
SSAP (8 bits):
Control (8 bits):
MSID (24 bits):
Type (16 bits):
* Note : If destination SRT bridge address in unknown, address
0100A2FFFFFF is used.
Note that when tunneling Ethernet data over a token ring
Ethernet
Data
Destination SRT Bridge *
Source SRT Bridge
AA (SNAP)
AA (SNAP)
03
000000
8103
Token Ring
Data
Destination SRT Bridge *
Source SRT Bridge
AA (SNAP)
AA (SNAP)
03
000000
8101