Cisco Systems First to Announce It Will Support DLSw Interoperability Standard
MENLO PARK, Calif., August 2, 1993 -- Consistent with its open standardsand interoperability strategy, Cisco Systems has announced it will supportthe new DLSw interoperability standard -- a method for integrating SNA andNetBIOS over the TCP/IP protocol -- currently being defined by the Data Link SwitchingWorking Group. The new DLSw standard provides interoperability and functionality not currently offered by Informational RFC 1434 or existing DLSw implementations. Cisco expects its IBM internetworking software suite will support the new DLSw standard in mid-1994. Specific ship dates will depend on the availability of the working group's DLSw specification.
In providing full DLSw interoperability, Cisco will retain compatibility with the comprehensive functionality its software currently offers while becoming compliant with the specification under development by the multivendor Data Link Switching Working Group. The Working Group was initiated by Cisco and is now operating as part of the APPN (Advanced Peer-to-Peer Networking) Implementors' Workshop.
"We believe the question is one of interoperability, not functionality, because Cisco and other vendors already ship routers with functionality beyond that currently defined in the Data Link Switching Informational RFC 1434 and existing DLSw implementations", said Michael Zadikian, Cisco SNA product manager. "In its current state, the Informational RFC specifies only a subset of the capabilities already offered by Cisco's IBM phases I through IV internetworking software that started shipping in early 1991. Additionally, the Informational RFC lacks sufficient information to ensure multivendor interoperability."
Features already offered by Cisco -- which the Working Group plans to incorporate into the DLSw interoperability specification -- include SDLCtunneling (STUN), prioritization, Class of Service, SNA Ethernet and flowcontrol. Cisco will retain additional features not expected to be part of the Working Group's specification that maximize the effective integration of legacy SNA and NetBIOS networks with LAN-based internets, including subarea networking functions (PU 4 to PU 4), PU Type 2.1, and inverse SDLLC (host on SDLC, controller onToken Ring).
According to Zadikian, "Since Cisco first introduced solutions for integrating SNA over TCP/IP, other vendors have followed with their own versions. As a result, a multiplicity of incompatible implementations, including Cisco's, IBM's, Proteon's, Wellfleet's, Crosscom's and others', exist in the market today. Now is the right time to introduce multivendor interoperability." Zadikian noted, however, that open issues regarding the operation of the Data Link Switching Working Group still exist. "It has not been resolved whether the working group will be an arm of IBM's AIW, subject to as-yet-undefined AIW rules, or whether it will generate its own operating rules, as ordinarily done in multivendor working groups."
Cisco Systems, inc., is the leading worldwide supplier ofhigh-performance, multimedia and multiprotocol internetworking products, including routers, bridges, communication servers and router management software. Cisco technology is used to build enterprise-wide networks linking an unlimited number of geographically dispersed LANs, WANs and IBM SNA networks. In the United States, Cisco is traded over the counter under NASDAQ symbol CSCO.