User`s guide

1-8

Introduction

With an innovative, multiple RISC processor architecture, the

ATX’s Packet Processing Engine is capable of ﬁltering and

forwarding at full line speed. Further, the ATX’s protocol-

independence and high performance allow for transparent, plug-

and-play network operation. The ATX offers all the beneﬁts of

interconnecting LANs across a backbone with an increase in

performance over existing bridges.

1.6.1 Netbios Name Caching

The ATX provides the capability of transforming certain Netbios

broadcast frames into non-broadcast frames. The speciﬁc frames

handled by Netbios Name Caching are those which seek to locate

another netbios station. These include Datagrams, Name Query,

and Name Recognized frames. For Netbios Name Caching to

function, it must be enabled on all ports for which Netbios trafﬁc

exists.

When the ATX receives any of these frames and Netbios Name

Caching is enabled on the port the frame was received on, the ATX

will identify the frame as a special Netbios Name Caching frame.

Once identiﬁed, a couple of actions takes place. First, the ATX

learns the Source Netbios name, the MAC address of the source

workstation, which port the station lives on and any applicable RIF

information. Second, the ATX determines if the destination

Netbios name has been learned. If the Netbios name is learned,

then the ATX replaces the broadcast address with the learned

unicast address, constructs an appropriate RIF is applicable, and

directs the frame to the appropriate port.

The ATX posseses name caching, the ability to reduce the amount

of broadcasts of certain Netbios session initialization frames.

Name Caching works by using certain frames (Name_Query

request and Name_Recognized response) within the Netbios

architeture to identify workstation names and their respective

hardware MAC address. Once the ATX identiﬁes a workstation

and its hardware MAC address, the workstation no longer needs

to ﬂood broadcasts to locate a particular destination on the

network; the ATX replaces the broadcast address with the learned