Visara FEP-4600 Planning Guide User Manual

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37x5 to FEP-4600 Migration and Planning Guide

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Data Link Switching (DLSw)

DLSw is a protocol described by RFC 1795 (and enhanced through RFC 2166) to provide
a means to encapsulate SNA traffic into an IP packet. Devices compatible to RFC 2166
are typically also backwards compatible to RFC 1795. There are also platforms still in
existence that are compatible to RFC 1434, a predecessor to RFC 1795. The FEP-4600 is
equipped with support for RFC 1795 DLSw which will negotiate compatibility with RFC
2166 platforms and is also directly compatible with RFC 1434 platforms.

DLSw gateway functionality is typically found in some routers. SNA traffic is received
by the router typically in the form of LLC2 packets and is encapsulated into IP packets
that can be transported over the wider IP network. A similar router platform is typically
located on the far side of the IP network to provide the de-encapsulation of the SNA
traffic from the IP packets which is then provided to the SNA platforms located at the far
end of the network. The SNA traffic may be in the form of LLC2 packets or perhaps
SDLC packets.

A typical DLSw network is shown below.

DLSw Router

3745

Mainframe

PU2 PC
Server

PU2 Controller

LLC2

SDLC