README.hdlc
1/*
2 * Copyright (c) University of British Columbia, 1984
3 *
4 * @(#)README.hdlc 8.1 (Berkeley) 06/10/93
5 *
6 * X.25 HDLC DATA LINK LEVEL:
7 *
8 *
9 * This module implements the Link Level of the Open Systems Interconnect
10 * Model. The implementation is based on the ISO High-Level Data Link
11 * Control (HDLC). These procedures subscribe to the principles of the
12 * ISO-Class of Procedures for point-to-point. These procedures implement
13 * two-way asynchronous balanced mode (LAPB) as recommented by the CCITT.
14 *
15 * The HDLC protocol layer interface consists of the following procedures:
16 * Hd_init (pr_init)
17 * Hd_ouput (pr_output)
18 * Hd_input (pr_input)
19 * Hd_timer (pr_slowtimo)
20 *
21 * Note: Supervisory commands RR, RNR and REJ are not transmitted by this
22 * station.
23 *
24 * This station never enters a busy (RNR) condition.
25 *
26 * The "Generate_rr" variable can be set to FALSE. This means that
27 * we NEVER send an RR. This works just fine if the network level
28 * is X.25 packet protocol -- which it is.
29 *
30 * Currently, this is only a DTE implementation.
31 *
32 * Think about:
33 * If the remote is busy, no iframes are sent. The remote sends a RR
34 * to clear this condition. However, this RR may be damaged, causing
35 * a possible deadlock. A solution is to poll with iframe (P(S)==P(R)
36 * of RNR) indefinitly.
37 *
38 *
39 * Date: February 1984
40 *
41 * Author: Gerald W. Neufeld
42 *
43 * Installation: Department of Computer Science
44 * University of British Columbia
45 * Vancouver, BC, CANADA.
46 *
47 * History:
48 *
49 *
50 */
51
README.packet
1/*
2 * @(#)README.packet 8.1 (Berkeley) 06/10/93
3 *
4 * X.25 NETWORK PACKET LEVEL:
5 *
6 * This implementation is based on Recommentation X.25 as agreed at the
7 * March 1976 and the February 1980 meetings of CCITT Study Group VII.
8 * However, not all aspects are implemented. The following is a list of
9 * features which are not yet or may never be implemented:
10 *
11 * 1. D bit
12 * 2. PVC
13 * 3. fast select
14 *
15 *
16 * Note: This implementation is for DTEs only.
17 *
18 * Currently, only the 1976 verison is implemented.
19 *
20 *
21 * Date: February, 1984
22 *
23 * Author: Gerald W. Neufeld
24 *
25 * Installation: Department of Computer Science
26 * University of British Columbia
27 * Vancouver, BC, CANADA
28 *
29 * To Do: Find some reasonable heuristic for piggybacking packet
30 * level acks.
31 *
32 * Bugs: Clear might be sent before data is all out.
33 *
34 * History:
35 *
36 */
37