EXP Computer S200 User Manual

Page of 162
Bridging 
17
T0008-16F
Release 5.2M
Bridge Hardware Components in PathBuilder S200 Series Switches
Bridge Hardware Components in PathBuilder S200 Series Switches
Introduction
This section describes bridge hardware configuration and connections for the 
PathBuilder S200 series switch.
Bridge 
Configuration and 
Connections
Figure 12 shows the physical connections of the modules that provide bridging 
functionality for PathBuilder S200 series switch. This figure shows a LAN port 
module and supporting WAN Adapter module within a PathBuilder S200 series 
switch. The LAN port module is broken out into a driver and a forwarder to show the 
concept of bridge links. 
At each end node, the bridge has connections referred to as bridge links. Bridge links 
that connect to the LAN are referred to as LAN bridge links. Bridge links that 
connect to remote bridges across the WAN are referred to as WAN bridge links.
Figure 12.  LAN Port Module and WAN Adapter Module (Logical View)
The LAN port consists of low level drivers and the bridge forwarder. This can be 
viewed as the functioning bridge. The WAN Adapter is closely associated with the 
bridge. The WAN Adapter provides the network services that the bridge requires in 
order to function over the WAN network. The principal service is establishing and 
maintaining SVC (PVC for Frame Relay) connections to remote LAN bridge 
forwarders so that virtual circuits can be formed between the forwarders.
The bridge sees the LAN and the WAN (by means of the WAN Adapter) as networks 
it is attached to by links. There are a total of 36 links: four LAN links and 32 WAN 
links.
LAN Interface 
Support
The PathBuilder S200 series switch supports only one LAN per node, so only one 
link is needed for the LAN port connection: link number 1. The PathBuilder S24x, 
26x, and 27x switch supports up to two Ethernet LANs per node. See “Dual LAN 
Ethernet” section on page 117 f
or more details on this functionality.
On the PathBuilder S200 series switch links numbered 2 to 4 are not used and are 
reserved for future configurations. WAN links are numbered 5 to 36 and provide up 
to 32 WAN connection links which correspond to potential bridges. 
Token
Ring
LAN
LAN
Driver
Up to 32 WAN links can be defined
(numbered 5 to 36), one for each
bridge connection over an SVC
(PVC for Frame Relay).
LAN
Bridge
Forwarder
WAN
Adaptor
5
.
.
.
.
32
1
LAN Link Numbers range from 1 to 
4: up to two LAN connections are 
supported for Ethernet.
X.25 SVCs connected to 
SVCs on network ports
(PVCs for Frame Relay)
LAN Port Module