Data-Link Switching

Data-Link Switching (DLSw) is a <a href="/facts/Tunneling_protocol/jKaT1Czc">tunneling protocol</a> designed to tunnel unroutable, non-IP based protocols such as IBM <a href="/facts/Systems_Network_Architecture/NlFaXaBC">Systems Network Architecture</a> (SNA) and <a href="/facts/NetBIOS_Frames/HQG9DoCb">NBF</a> over an IP network.
DLSw was initially documented in IETF RFC 1434 in 1993. In 1995 it was further documented in the IETF RFC 1795. DLSw version 2 was presented in 1997 in IETF RFC 2166 as an improvement to RFC 1795. <a href="/facts/Cisco/ocDgQt6T">Cisco</a> Systems has its own proprietary extensions to DLSw in DLSw+. According to Cisco, DLSw+ is 100% IETF RFC 1795 compliant but includes some proprietary extensions that can be used when both devices are Cisco.
Some organisations are starting to replace DLSw tunneling with the more modern <a href="/facts/Enterprise_Extender/aMN5De6V">Enterprise Extender</a> (EE) protocol which is a feature of IBM APPN on z/OS systems. Microsoft refers to EE as IPDLC. Enterprise Extender uses UDP traffic at the <a href="/facts/Transport_layer/UmIGUCeK">transport layer</a> rather than the <a href="/facts/Network_layer/L2jAtJzQ">network layer</a>.
Cisco deploy Enterprise Extender on their hardware via the IOS feature known as SNAsW (SNA Switch).

Data-Link Switching open-in-new

Data-Link Switching