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Data Link Switching Client Access Protocol (RFC2114)

IP.com Disclosure Number: IPCOM000002667D
Original Publication Date: 1997-Feb-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 17 page(s) / 47K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

S. Chiang: AUTHOR [+3]

Abstract

This memo describes the Data Link Switching Client Access Protocol that is used between workstations and routers to transport SNA/ NetBIOS traffic over TCP sessions. Any questions or comments should be sent to dcap@cisco.com.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 6% of the total text.

Network Working Group S. Chiang

Request for Comments: 2114 J. Lee

Category: Informational Cisco Systems, Inc.

Obsoletes: 2106 H. Yasuda

Mitsubishi Electric Corp.

February 1997

Data Link Switching Client Access Protocol

Status of this Memo

This memo provides information for the Internet community. This memo

does not specify an Internet standard of any kind. Distribution of

this memo is unlimited.

Abstract

This memo describes the Data Link Switching Client Access Protocol

that is used between workstations and routers to transport SNA/

NetBIOS traffic over TCP sessions. Any questions or comments should

be sent to dcap@cisco.com.

Table of Contents

1. Introduction ............................................ 2

2. Overview ................................................ 2

2.1 DCAP Client/Server Model ............................... 2

2.2 Dynamic Address Resolution ............................. 3

2.3 TCP Connection ......................................... 4

2.4 Multicast and Unicast (UDP) ............................ 4

3. DCAP Format ............................................. 6

3.1 General Frame Format ................................... 6

3.2 Header Format .......................................... 6

3.3 DCAP Messages .......................................... 7

3.4 DCAP Data formats ...................................... 8

3.4.1 CAN_U_REACH, I_CAN_REACH, and I_CANNOT_REACH Frames .. 8

3.4.2 START_DL, DL_STARTED, and START_DL_FAILED Frames ..... 9

3.4.3 HALT_DL, HALT_DL_NOACK, and DL_HALTED Frames ......... 13

3.4.4 XID_FRAME, CONTACT_STN, STN_CONTACTED, INFO_FRAME,

FCM_FRAME, and DGRM_FRAME ............................ 14

3.4.5 DATA_FRAME ........................................... 15

3.4.6 CAP_XCHANGE Frame .................................... 16

3.4.7 CLOSE_PEER_REQ Frames ................................ 19

3.4.8 CLOSE_PEER_RSP, PEER_TEST_REQ, and PEER_TEST_RSP Frames 20

4. Protocol Flow Diagram ................................... 20

5. Acknowledgments ......................................... 22

6. References .............................................. 22

1. Introduction

Since the Data Link Switching Protocol, RFC 1795, was published, some

software vendors have begun implementing DLSw on workstations. The

implementation of DLSw on a large number of workstations raises

several important issues that must be addressed. Scalability is the

major concern. For example, the number of TCP sessions to the DLSw

router increases in direct proportion to the number of workstations

added. Another concern is efficiency. Since DLSw is a switch-to-

switch ...