Link Layer Interface

Link Layer Interface

1 Introduction

UNIX System V Release 3.2 included a Logical Link Interface (LLI) that was later standardized as the Data Link Provider Interface (DLPI) by the Open Group.¹

The Link Layer Interface (LLI) was developed by Spider Systems, Ltd., (now a division of Emerson Power) and is widely available on many platforms. For example, AIX AIXlink/X.25, HP-UX X.25/9000, IRIX IRIS SX.25, PT X.25, RadiSys WAN, SBE X.25, Solaris SunLink X.25 and Solaris Solstice X.25, implement the Link Layer Interface (LLI).²

The Link Layer Interface (LLI) as designed to be used directly with standard STREAMS system calls and does not require the use of a cooperating user space shared library. Applications programs directly use the getmsg(2s), getpmsg(2), putmsg(2s), putpmsg(2) and ioctl(2) system calls.³ Nevertheless, user shared object libraries can easily be constructed using this STREAMS service primitive interface.

The system header files that must be included when compiling user applications, or STREAMS drivers and modules that use the interface, are detailed in LLI Header Files.

A user library, libsx25, is provided, not for interfacing to the message primitive service interface, but for providing various helper functions when using the STREAMS service interface. This library is detailed in LLI Library.

2 Model of the Link Layer

3 LLI Services

3.1 LLI Commands

3.2 LLI Data Structures

4 LLI Message Primitives

Although it perhaps did not at first, the LLI uses the service primitives and message format of the Data Link Provider Interface, DLPI.

5 LLI Input-Output Controls

5.1 Input-Output Control Data Structures

The /usr/include/strx25/sys/snet/ll_control.h header file (<sys/snet/ll_control.h> with proper compile flags) defines a number of structures, pointers to which are used as argumnets to input-output controls. These structures fall into four classes, identified by the value of the first byte of the structure, as follows:

5.1.1 LI_PLAIN - Plain Data Structures

5.1.1.1 ll_hdioc Structure

The ll_hdioc structure is formatted as follows:

     struct ll_hdioc {
         uint8_t lli_type;
         uint8_t lli_spare[3];
         uint32_t lli_snid;
     };

The ll_hdioc structure contains the following members:

lli_type

Always LLI_PLAIN.

lli_spare

Spare bytes for alignment: set to zero by issuer and ignored by responder.

lli_snid

Specifies the subnetwork identifier (link identifier) for the operation.

5.1.2 LI_SNID - Subnetwork Identifier Data Strucures

5.1.2.1 ll_snioc Structure

The ll_snioc structure is used in the L_SETSNID, L_GETSNID, M_SETSNID and M_GETSNID input-output controls.

The ll_snioc structure is formatted as follows:

     struct ll_snioc {
         uint8_t lli_type;
         uint8_t lli_class;
         uint8_t lli_spare[2];
         uint32_t lli_snid;
         uint32_t lli_index;
         uint32_t lli_slp_snid;
         uint16_t lli_slp_pri;
     };

The ll_snioc structure contains the following members:

lli_type

Always LLI_SNID.

lli_class

Specifies the class of the link being registered. This field can be one of the following values:

LC_LLC1	LLC Type 1 link.
LC_LLC2	LLC TYpe 2 link.
LC_LAPBDTE	LAPB DTE.
LC_LAPBXDTE	LAPB DTE with extended addressing.
LC_LAPBDCE	LAPB DCE.
LC_LAPBXDCE	LAPB DCE with extended addressing.
LC_LAPDTE	LAP DTE.
LC_LAPDCE	LAP DCE.
LC_HDLC	HDLC.
LC_HDLCX	HDLC with extended addressing.
LC_MLAPBDTE	LAPB DTE multilink.
LC_MLAPBXDTE	LAPB DTE multilink with extended addressing.
LC_MLAPBDCE	LAPB DCE multilink.
LC_MLAPBXDCE	LAPB DCE multilink with extended addressing.
LC_MLP	MLP link.

lli_spare

Spare bytes for alignment: set to zero by issuer and ignored by responder.

lli_snid

Specifies the subnetwork identifier (link identifier) for the operation.

lli_index

Specifies the lower multiplex identifier of the Stream linked under a multiplexing driver as returned from I_LINK(7).⁴

lli_slp_snid

Specifies the subnetwork (link) identifier for an SLP link within an MLP link.

lli_slp_pri

Specifies the subnetwork (link) priority within an MLP link.

5.1.3 LI_STATUS - Status Data Strucures

5.1.3.1 ll_stnioc Structure

The ll_stnioc structure is formatted as follows:

     struct ll_stnioc {
         uint8_t lli_type;
         uint8_t lli_spare[3];
         uint32_t lli_snid;
     };

The ll_stnioc structure contains the following members:

lli_type

Always LLI_STATUS.

lli_spare

Spare bytes for alignment: set to zero by issuer and ignored by responder.

lli_snid

Specifies the subnetwork identifier (link identifier) for the operation.

5.1.4 LI_STATS - Statistics Data Structures

5.1.4.1 lapb_stioc Structure

The lapb_stioc structure is formatted as follows:

     struct lapb_stioc {
         uint8_t lli_type;
         uint8_t state;
         uint16_t lli_spare;
         uint32_t lli_snid;
         lapbstats_t lli_stats;
     };

The lapb_stioc structure contains the following members:

lli_type

Always LLI_STATS.

state

lli_spare

Spare bytes for alignment: set to zero by issuer and ignored by responder.

lli_snid

Specifies the subnetwork identifier (link identifier) for the operation.

lli_stats

Contains the lapbstats_t structure described in lapbstats_t Structure.

5.1.4.2 lapbstats_t Structure

The lapbstats_t structure is formatted as follows:

     typedef struct lapb_stats {
         uint32_t lapbmonarray[49];
     } lapbstats_t;

The lapbstats_t structure contains the following members:

lapbmonarray

Provides an array of 32-bit unsigned integers containing statistics. The indexes of the elements of the array are as follows:

0	tx_ign	-
1	rx_badlen	-
2	rx_unknown	-
3	t1_exp	-
4	t4_exp	-
5	t4_n2_exp	-
6	RR_rx_cmd	-
7	RR_rx_rsp	-
8	RR_tx_cmd	-
9	RR_tx_rsp	-
10	RR_tx_cmd_p	-
11	RNR_rx_cmd	-
12	RNR_rx_rsp	-
13	RNR_tx_cmd	-
14	RNR_tx_rsp	-
15	RNR_tx_cmd_p	-
16	REJ_rx_cmd	-
17	REJ_rx_rsp	-
18	REJ_tx_cmd	-
19	REJ_tx_rsp	-
20	REJ_tx_cmd_p	-
21	SABME_rx_cmd	-
22	SABME_tx_cmd	-
23	DISC_rx_cmd	-
24	DISC_tx_cmd	-
25	UA_rx_rsp	-
26	UA_tx_rsp	-
27	DM_rx_rsp	-
28	DM_tx_rsp	-
29	I_rx_cmd	-
30	I_tx_cmd	-
31	FRMR_rx_rsp	-
32	FRMR_tx_rsp	-
33	tx_rtr	-
34	rx_bad	-
35	rx_dud	-
36	rx_ign	-
37	XID_rx_cmd	-
38	XID_rx_rsp	-
39	XID_tx_cmd	-
40	XID_tx_rsp	-
41	TEST_rx_cmd	-
42	TEST_rx_rsp	-
43	TEST_tx_cmd	-
44	TEST_tx_rsp	-
45	SABM_rx_cmd	-
46	SABM_tx_cmd	-
47	SARM_rx_cmd	-
48	SARM_tx_cmd	-

5.1.4.3 llc2_stioc Structure

The llc2_stioc structure is formatted as follows:

     struct llc2_stioc {
         uint8_t lli_type;
         uint8_t lli_spare[3];
         uint32_t lli_snid;
         llc2stats_t lli_stats;
     };

The llc2_stioc structure contains the following members:

lli_type

Always LLI_STATS.

lli_spare

Spare bytes for alignment: set to zero by issuer and ignored by responder.

lli_snid

Specifies the subnetwork identifier (link identifier) for the operation.

lli_stats

Contains the llc2stats_t structure containing the statistics described in llc2stats_t Structure.

5.1.4.4 llc2stats_t Structure

The llc2stats_t structure is formatted as follows:

     typedef struct llc2_stats {
         uint32_t llc2monarray[49];
     } llc2stats_t;

The llc2stats_t structure contains the following members:

llc2monarray

Provides an array of 32-bit unsigned integers containing the statistics. The indices of the individual elements are as follows:

0	tx_ign	-
1	rx_badlen	-
2	rx_unknown	-
3	t1_exp	-
4	t4_exp	-
5	t4_n2_exp	-
6	RR_rx_cmd	-
7	RR_rx_rsp	-
8	RR_tx_cmd	-
9	RR_tx_rsp	-
10	RR_tx_cmd_p	-
11	RNR_rx_cmd	-
12	RNR_rx_rsp	-
13	RNR_tx_cmd	-
14	RNR_tx_rsp	-
15	RNR_tx_cmd_p	-
16	REJ_rx_cmd	-
17	REJ_rx_rsp	-
18	REJ_tx_cmd	-
19	REJ_tx_rsp	-
20	REJ_tx_cmd_p	-
21	SABME_rx_cmd	-
22	SABME_tx_cmd	-
23	DISC_rx_cmd	-
24	DISC_tx_cmd	-
25	UA_rx_rsp	-
26	UA_tx_rsp	-
27	DM_rx_rsp	-
28	DM_tx_rsp	-
29	I_rx_cmd	-
30	I_tx_cmd	-
31	FRMR_rx_rsp	-
32	FRMR_tx_rsp	-
33	tx_rtr	-
34	rx_bad	-
35	rx_dud	-
36	rx_ign	-
37	XID_rx_cmd	-
38	XID_rx_rsp	-
39	XID_tx_cmd	-
40	XID_tx_rsp	-
41	TEST_rx_cmd	-
42	TEST_rx_rsp	-
43	TEST_tx_cmd	-
44	TEST_tx_rsp	-
45	I_rx_rsp	-
46	I_tx_rsp	-
47	UI_rx_cmd	-
48	UI_tx_cmd	-

5.1.4.5 mlp_stioc Structure

The mlp_stioc structure is formatted as follows:

     struct mlp_stioc {
         uint8_t lli_type;
         uint8_t state;
         uint16_t lli_spare;
         uint32_t lli_snid;
         mlpstats_t lli_stats;
     };

The mlp_stioc structure contains the following members:

lli_type

Always LLI_STATS.

lli_state

Provides the state of the link.

lli_spare

Spare bytes for alignment: set to zero by issuer and ignored by responder.

lli_snid

Specifies the subnetwork identifier (link identifier) for the operation.

lli_stats

Contains the mlpstats_t structure containing the statistics described in mlpstats_t Structure.

5.1.4.6 mlpstats_t Structure

The mlpstats_t structure is formatted as follows:

     typedef struct mlp_stats {
         uint32_t mlpmonarray[12];
     } mlpstats_t;

The mlpstats_t structure contains the following members:

mlpmonarray

Contains an array of 32-bit unsigned integers containing the statistics. The indices of the individual elements of the array are as follows:

0	MLP_frames_tx	-
1	MLP_frames_rx	-
2	MLP_reset_tx	-
3	MLP_reset_rx	-
4	MLP_confs_tx	-
5	MLP_confs_rx	-
6	MLP_slps	-
7	MLP_num_slps	-
8	MLP_mt1_exp	-
9	MLP_mt2_exp	-
10	MLP_mt3_exp	-
11	MLP_mn1_exp	-

5.1.5 LI_GSTATS - Global Statistics Data Structures

5.1.5.1 lapb_gstioc Structure

The lapb_gstioc structure is formatted as follows:

     struct lapb_gstioc {
         uint8_t lli_type;
         uint8_t lli_spare[3];
         uint32_t lapbgstats[6];
     };

The lapb_gstioc structure contains the following members:

lli_type

Always LLI_GSTATS.

lli_spare

Spare bytes for alignment: set to zero by issuer and ignored by responder.

lapbgstats

Contains an array of 32-bit unsigned integers containing the statistics. The indices of the individual elements of the array are as follows:

0	frames_tx	-
1	frames_rx	-
2	sabm_tx	-
3	sabm_rx	-
4	bytes_tx	-
5	bytes_rx	-

5.1.5.2 llc2_gstioc Structure

The llc2_gstioc structure is formatted as follows:

     struct llc2_gstioc {
         uint8_t lli_type;
         uint8_t lli_spare[3];
         uint32_t llc2gstats[6];
     };

The llc2_gstioc structure contains the following members:

lli_type

Always LLI_GSTATS.

lli_spare

Spare bytes for alignment: set to zero by issuer and ignored by responder.

llc2gstats

Contains an array of 32-bit unsigned integers containing the statistics. The indices of the individual elements of the array are as follows:

0	frames_tx	-
1	frames_rx	-
2	sabme_tx	-
3	sabme_rx	-
4	bytes_tx	-
5	bytes_rx	-

5.1.5.3 mlp_gstioc Structure

The mlp_gstioc structure is formatted as follows:

     struct mlp_gstioc {
         uint8_t lli_type;
         uint8_t lli_spare[3];
         uint32_t mlpgstats[10];
     };

The mlp_gstioc structure contains the following members:

lli_type

Always LLI_GSTATS.

lli_spare

Spare bytes for alignment: set to zero by issuer and ignored by responder.

mlpgstats

Contains an array of 32-bit unsigned integers containing the statistics. The indices of the individual elements of the array are as follows:

0	MLP_frames_tx	-
1	MLP_frames_rx	-
2	MLP_reset_tx	-
3	MLP_reset_rx	-
4	MLP_confs_tx	-
5	MLP_confs_rx	-
6	MLP_slps	-
7	MLP_num_slps	-
8	MLP_bytes_tx	-
9	MLP_bytes_rx	-

5.1.6 LI_LAPBTUNE - LAPB Tuning Data Structures

5.1.6.1 lapb_tnioc Structure

The lapb_tnioc structure is formatted as follows:

     struct lapb_tnioc {
         uint8_t lli_type;
         uint8_t lli_spare[3];
         uint32_t lli_snid;
         lapbtune_t lapb_tune;
     };

The lapb_tnioc structure contains the following members:

lli_type

Always LLI_LAPBTUNE.

lli_spare

Spare bytes for alignment: set to zero by issuer and ignored by responder.

lli_snid

Specifies the subnetwork identifier (link identifier) for the operation.

lapb_tune

Contains the lapbtune_t tuning structure containing tuning parameters described in lapbtune_t Structure.

5.1.6.2 lapbtune_t Structure

The labtune_t structure is formatted as follows:

     typedef struct lapbtune {
         uint16_t N2;
         uint16_t T1;
         uint16_t Tpf;
         uint16_t Trej;
         uint16_t Tbusy;
         uint16_t Tidle;
         uint16_t ack_delay;
         uint16_t notack_max;
         uint16_t tx_window;
         uint16_t tx_probe;
         uint16_t max_I_len;
         uint16_t llconform;
         uint16_t sabm_in_x32;
     } lapbtune_t;

The lapbtune_t structure contains the following members:

N2

T1

Tpf

Trej

Tbusy

Tidle

ack_delay

notack_max

tx_window

tx_probe

max_I_len

llconform

sabm_in_x32

5.1.7 LI_LLC2TUNE - LLC2 Tuning Data Structures

5.1.7.1 llc2_tnioc Structure

The llc2_tnioc structure is formatted as follows:

     struct llc2_tnioc {
         uint8_t lli_type;
         uint8_t lli_spare[3];
         uint32_t lli_snid;
         llc2tune_t llc2_tune;
     };

The llc2_tnioc structure contains the following members:

lli_type

Always LLI_LLC2TUNE.

lli_spare

Spare bytes for alignment: set to zero by issuer and ignored by responder.

lli_snid

Specifies the subnetwork identifier (link identifier) for the operation.

llc2_tune

Contains the llc2tune_t tuning structure containing tuning parameters described in llc2tune_t Structure.

5.1.7.2 llc2tune_t Structure

The llc2tune_t structure is formatted as follows:

     typedef struct llc2tune {
         uint16_t N2;
         uint16_t T1;
         uint16_t Tpf;
         uint16_t Trej;
         uint16_t Tbusy;
         uint16_t Tidle;
         uint16_t ack_delay;
         uint16_t notack_max;
         uint16_t tx_window;
         uint16_t tx_probe;
         uint16_t max_I_len;
         uint16_t xid_window;
         uint16_t xid_Ndup;
         uint16_t xid_Tdup;
     } llc2tune_t;

The llc2tune_t structure contains the following members:

N2

T1

Tpf

Trej

Tbusy

Tidle

ack_delay

notack_max

tx_window

tx_probe

max_I_len

xid_window

xid_Ndup

xid_Tdup

5.1.8 LI_MLPTUNE - MLP Tuning Data Structures

5.1.8.1 mlp_tnioc Structure

The mlp_tnioc structure is formatted as follows:

     struct mlp_tnioc {
         uint8_t lli_type;
         uint8_t lli_spare[3];
         uint32_t lli_snid;
         mlptune_t mlp_tune;
     };

The mlp_tnioc structure contains the following members:

lli_type

Always LLI_MLPTUNE.

lli_spare

Spare bytes for alignment: set to zero by issuer and ignored by responder.

lli_snid

Specifies the subnetwork identifier (link identifier) for the operation.

mlp_tune

Contains the mlptune_t tuning structure containing tuning parameters described in mlptune_t Structure.

5.1.8.2 mlptune_t Structure

The mlptune_t structure is formatted as follows:

     typedef struct mlptune {
         uint16_t mw;
         uint16_t mx;
         uint16_t mt1;
         uint16_t mt2;
         uint16_t mt3;
         uint16_t mn1;
     } mlptune_t;

The mlptune_t structure contains the following members:

mw

The size of the MLP window.

mx

The size of the MLP guard region.

mt1

The time interval to wait for MN(S) == MV(R) in deciseconds.

mt2

The time interval to wait for unblock in deciseconds.

mt3

The time interval to wait for reset confirmation.

mn1

The number of SLP transmission retries.

5.2 Input-Output Control Commands

5.2.1 SLP Input-Output Control Commands

5.2.1.1 L_SETSNID

The argument of this input-output control is a pointer to the ll_snioc structure described in ll_snioc Structure.

5.2.1.2 L_GETSNID

The argument of this input-output control is a pointer to the ll_snioc structure described in ll_snioc Structure.

5.2.1.3 L_SETTUNE

The argument of this input-output control is a pointer to the lapb_tnioc, llc2_tnioc or mlp_tnioc structure.⁵

5.2.1.4 L_GETTUNE

The argument of this input-output control is a pointer to the lapb_tnioc, llc2_tnioc or mlp_tnioc structure.⁶

5.2.1.5 L_GETSTATS

The argument of this input-output control is a pointer to the lapb_stioc, llc2_stioc or mlp_stioc structure.⁷

5.2.1.6 L_ZEROSTATS

The argument of this input-output control is a pointer to the lapb_stioc, llc2_stioc or mlp_stioc structure.⁸

5.2.1.7 L_TRACEON

The argument of this input-output control is a pointer to the ll_hdioc structure described in ll_hdioc Structure.

5.2.1.8 L_TRACEOFF

The argument of this input-output control is a pointer to the ll_hdioc structure described in ll_hdioc Structure.

5.2.1.9 L_GETGSTATS

The argument of this input-output control is a pointer to the lapb_gstioc, llc2_gstioc or mlp_gstioc structure.⁹

5.2.1.10 L_ZEROGSTATS

The argument of this input-output control is a pointer to the lapb_gstioc, llc2_gstioc or mlp_gstioc structure.¹⁰

5.2.1.11 L_LINKDISABLE

The argument of this input-output control is a pointer to the ll_hdioc structure described in ll_hdioc Structure.

5.2.1.12 L_LINKENABLE

The argument of this input-output control is a pointer to the ll_hdioc structure described in ll_hdioc Structure.

5.2.1.13 L_PUTX32MAP

5.2.1.14 L_GETX32MAP

5.2.2 MLP Input-Output Control Commands

5.2.2.1 M_SETSNID

The argument of this input-output control is a pointer to the ll_snioc structure described in ll_snioc Structure.

5.2.2.2 M_GETSNID

The argument of this input-output control is a pointer to the ll_snioc structure described in ll_snioc Structure.

5.2.2.3 M_SETTUNE

The argument of this input-output control is a pointer to the lapb_tnioc, llc2_tnioc or mlp_tnioc structure.¹¹

5.2.2.4 M_GETTUNE

The argument of this input-output control is a pointer to the lapb_tnioc, llc2_tnioc or mlp_tnioc structure.¹²

5.2.2.5 M_GETSTATS

The argument of this input-output control is a pointer to the lapb_stioc, llc2_stioc or mlp_stioc structure.¹³

5.2.2.6 M_ZEROSTATS

The argument of this input-output control is a pointer to the lapb_stioc, llc2_stioc or mlp_stioc structure.¹⁴

5.2.2.7 M_TRACEON

The argument of this input-output control is a pointer to the ll_hdioc structure described in ll_hdioc Structure.

5.2.2.8 M_TRACEOFF

The argument of this input-output control is a pointer to the ll_hdioc structure described in ll_hdioc Structure.

5.2.2.9 M_GETGSTATS

The argument of this input-output control is a pointer to the lapb_gstioc, llc2_gstioc or mlp_gstioc structure.¹⁵

5.2.2.10 M_ZEROGSTATS

The argument of this input-output control is a pointer to the lapb_gstioc, llc2_gstioc or mlp_gstioc structure.¹⁶

6 LLI Header Files

6.1 ll_control.h Header File

6.2 ll_proto.h Header File

6.3 mlp_control.h Header File

6.4 mlp_proto.h Header File

7 LLI Drivers and Modules

7.1 hdlc Driver

The hdlc driver is a pseudo-device STREAMS driver that provides raw HDLC framing as specified in ISO/IEC 3309 described in reference ISO3309.

The hdlc driver provides a Data Link Provider Interface as its upper multiplex service interface, as described in DLPI.

The hdlc driver is documented in the hdlc(4) manual page.

7.2 lapb Driver

The lapb driver is a pseudo-device STREAMS driver that provides the X.25 compatible LAPB procedures as specified in ISO/IEC 7776 described in reference ISO7776. This driver, in combination with the x25 multiplexing driver, provides X.25 over LAPB as described in reference ISO8208.

The lapb driver provides a Data Link Provider Interface as its upper multiplex service interface, as described in DLPI.

The lapb driver is documented in the lapb(4) manual page.

7.3 llc1 Driver

The llc1 driver is a pseudo-device STREAMS driver that provides the IEEE 802.2 LLC Type 1 (LLC1) procedures as specified in ISO/IEC 8802-2 described in reference ISO8802-2. This driver, in combination with the x25 multiplexing driver, provides X.25 over LLC1 as described in refeference ISO8881.

The llc1 driver provides a Data Link Provider Interface as its upper multiplex service interface, as described in DLPI.

The llc1 driver is documented in the llc1(4) manual page.

7.4 llc2 Driver

The llc1 driver is a pseudo-device STREAMS driver that provides the IEEE 802.2 LLC Type 2 (LLC2) procedures as specified in ISO/IEC 8802-2 described in reference ISO8802-2. This driver, in combination with the x25 multiplexing driver, provides X.25 over LLC2 as described in refeference ISO8881.

The llc2 driver provides a Data Link Provider Interface as its upper multiplex service interface, as described in DLPI.

The llc2 driver is documented in the llc2(4) manual page.

7.5 s_llic Module

The s_llic module is a pushable STREAMS module that converts between the LLI input-output controls described in this manual and the DLPI input-output controls used by the OpenSS7 Project. This particular module does not convert primitives, as both the LLI and the DLPI use the primitives of the Data Link Provider Interface, Revision 2.0.0 described in reference DLPI.

The s_llic module provides a Data Link Provider Interface as its upper and lower service interface, as described in DLPI.

The s_llic module is documented in the s_llic(4) manual page.

7.6 s_lli Module

The s_lli module is a pushable STREAMS module that converts between the LLI input-output controls described in this manual and the DLPI input-output controls used by the OpenSS7 Project. This particular module converts between the LLI primitives described in this manual and the primitives of the Data Link Provider Interface, described in reference DLPI.

The s_llic module provides a Data Link Provider Interface as its upper and lower service interface, as described in DLPI.

The s_lli module is documented in the s_lli(4) manual page.

8 LLI Utilities

8.1 lltune Utility

The lltune utility is documented in the lltune(8) manual page.

8.2 mlptune Utility

The mlptune utility is documented in the mlptune(8) manual page.

8.3 linkadd Utility

The linkadd utility is documented in the linkadd(8) manual page.

8.4 linkdel Utility

The linkdel utility is documented in the linkdel(8) manual page.

8.5 linklist Utility

The linklist utility is documented in the linklist(8) manual page.

8.6 linkreset Utility

The linkreset utility is documented in the linkreset(8) manual page.

8.7 linkstart Utility

The linkstart utility is documented in the linkstart(8) manual page.

8.8 linkstate Utility

The linkstate utility is documented in the linkstate(8) manual page.

8.9 linkstop Utility

The linkstop utility is documented in the linkstop(8) manual page.

9 LLI File Formats

9.1 lapbtemplate File Format

The lapbtemplate file format is documented in the lapbtemplate(5) manual page.

Name

lapbtemplate — Link Access Protocol (Balanced) File Format

Description

The lapbtemplate describes the file format for input to the lltune(8) command for LAPB class subnetworks. The file format consists of a number of parameter values, one per line, formatted as described below. Each parameter value is described using its line number in the file, a parameter name, and a description of the format of the value. Only the value appears in the file, each value on a line by itself, one value per line.

Each of the LAPB configuration parameters correspons to the member and values of the lapb_tune structure, that is carried in a lapb_tnioc structure by the L_LAPBTUNE input-output control.

These protocol parameters, and the default values that exist when tuning has not been applied to a newly created LAPB subnetwork, correspond directly to the protocol parameters and defaults in ISO/IEC 7776, ITU-T Rec. X.25 and X.75.

Format

The LAPB template consists of 16 to 18 lines containing the following configuration information:

1. N2_VAL is the maximum number of times that a protocol data unit (PDU) is set following the expiry of the acknowlegement timer, the P-bit timer, or the reject timer. It also limits the number of times an RR with the P-bit set is sent when remote busy is true and the busy timer expires.
2. T1_VAL is the time during which the LAPB expects to receive an acknowledgement to an outstanding I-PDU or an expected response to a sent UI-PDU. The value is in units of 0.1 seconds (deciseconds).
3. TPF_VAL is the time during which the LAPB expectes to receive a PDU with the F-bit set to 1 in response to a command with the P-bit set to 1. The value should be less than the acknowledgement timer. The value is in units of 0.1 seconds (deciseconds).
4. TREJ_VAL is the time interval during which the LAPB expects to receive a reply to a sent REJ DPU. The value is in units of 0.1 seconds (deciseconds).
5. TBUSY_VAL is the time interval during which the LAPB waits for an indication of the clearance of a busy condition at the other LAPB. The value is in units of 0.1 seconds (deciseconds).
6. IDLE_VAL is the time interval during which the LAPB expects to receive a PDU from the other LAPB. If it expires then the P/F cycle is intiated which may result in link disconnection. The value is in units of 0.1 seconds (decicseconds).
7. ACK_DELAY is the maximum delay in 0.1 second units before transmitting a delayed RR. This must be considerably less that the acknowledgement timer value, T1_VAL.
8. NOTACK_MAX is the maximuum number of unacknowledged receive I PDUs before the RR acknowledging them all must be sent.
9. LOC_WIND is the number of unacknowledged I PDUs that may be sent.
10. LOC_PROBE is the position before the window is closed at which an I PDU is sent with the P-bit set to solicit an acknowledgement from the receiver.
11. MAX_I_LEN is the maximum isze of a LAPB I-frame. LAPB requires all incoming I-frames above a certain size to be rejected by a FRMR. This parameter specifies the maximum size. It is constructured as the sum of the maximum X.25 data size, the X.25 protocol length and the LAPB protocol length.
12. IGN_UA_ERROR define whether or not to ignore any UA frams received, when the connection is in ERROR state. The value is ‘1’ for true and ‘0’ for false. The defalt value is false.
13. FRMR_FRMR_ERROR defines whether or not to re-transmit a frame reject if a frame reject is received, when the connection is in ERROR state. The value is ‘1’ for true and ‘0’ for false. The default value is false.
14. FRMR_INVRSP_ERROR defines whether or not to transmit a frame reject if an invalid frame response is received, when the connection is in ERROR state. The value is ‘1’ for true and ‘0’ for false. The default value is false.
15. SFRAME_PBIT defines whether or not to send a frame reject if an S-frame is received without the P-bit set. The value is ‘1’ for truea nd ‘0’ for false. The default value is false.
16. NO_DM_ADM defines whether or not to send a DM on entry to ADM state after an N2 count expiry. The value is ‘1’ for true and ‘0’ for false. The default value is false.

The following two fields are optional extensions:

17. IGN_DM_ERROR defines whether or not to ignore DM frames received, when the connection is in ERROR state. The value is ‘1’ for true and ‘0’ for false. The default value is false.
18. SABM_IN_X32 defines the action to take when a SABM is received in X.32 setup. The value is ‘1’ for true and ‘0’ for false. The default value is false.

The last two fields (‘17’ and ‘18’) are enhancements.

Files

Files following this format are normally kept in the /etc/sysconfig/strx25/template/ directory.¹⁷

See Also

• lltune(8)
• lapb(4)
• x25netd(8)

Compatibility

The lapbtemplate file format is compatible with Spider X.25, and implementations based on Spider X.25, such as AIXlink/X.25, HP-UX, IRIS SX.25, Solstice X.25, PT X.25, SBE X.25, with the following compatibility considerations:

• Most implementations only define the first 16 lines. This implementation defines 18 lines, where the first 16 lines are compatible with other implementations and the last additional two lines are optional.
• PT X.25 documents the SABM_IN_X32 LAPB template field but not the IGN_DM_ERROR LAPB template field. Solstice X.25 and IRIS SX.25 do not document either the IGN_DM_ERROR nor SABM_IN_X32 LAPB template fields.

For additional compatiblity infromation see, lapb(4), and STREAMS(9).

Conformance

AIXlink/X.25, HP-UX, IRIS SX.25, Solstice X.25, PT X.25, SBE X.25, documentation.

History

The lapbtemplate file format first appeared in Spider X.25.

9.2 llc2template File Format

The llc2template file format is documented in the llc2template(5) manual page.

Name

llc2template — Logical Link Control Type 2 File Format

Description

The llc2template describes the file format for input to the lltune(8) command for LLC2 class subnetworks. The file format consists of a number of parameter values, one per line, formatted as described below. Each parameter value is described using its line number in the file, a parameter name, and a description of the format of the value. Only the value appears in the file, each value on a line by itself, one value per line.

Each of the LLC2 configuration parameters corresponds to the member and values of the llc2_tune structure, that is carried in a llc2_tnioc structure by the L_LLC2TUNE input-output control.

These protocol parameters, and the default values that exist when tuning has not been applied to a newly created LLC2 subnetwork, correspond directly to the protocol parameters and defaults in ISO/IEC 8802-2:1998.

Format

The LLC2 template consists of 14 lines containing the following configuration information.

1. N2_VAL is the maximum number of times that a Protocol Data Unit (PDU) is sent following the expiry of the acknowledgement timer, the P-bit timer, or the reject timer. This parameter also limits the number of times an RR is sent with the P-bit set when remote busy is true and the busy timer expires.
2. T1_VAL is the time interval during which the LLC2 expects to receive an acknowledgement to an outstanding I-PDU or an expected response to a sent UI-PDU. The value is in units of 0.1 seconds.
3. TPF_VAL is the time during which the LLC2 expects to receive a PDU with the F-bit set to 1 in response to a command with the P-bit set to 1. The value should be less than that specified for the akcnowledgement timer. The value is in units of 0.1 seconds.
4. TREJ_VAL is the time interval during which the LLC2 expects to receive a reply to a sent REJ PDU. The value is in units of 0.1 seconds.
5. TBUSY_VAL is the timer interval during which the LLC2 waits for an indication of the clearance of busy condition at the other LLC2. The value is in units of 0.1 seconds.
6. TIDLE_VAL is the time interval during which the LLC2 expects to receive a PDU from the other LLC2. The value is in units of 0.1 seconds.
7. ACK_DELAY is the RR delay time. This is the time interval for which the LLC2 will withhold acknowledgements of unacknowledged received I-PDUs. The value is in units of 0.1 seconds.
8. NOTACK_MAX is the maximum number of unacknowledged received I-frames.
9. TX_WINDOW is the transmit window (if no XID received).
10. TX_PROBE is the position before the window is closed at which an I-PDU is sent with the P-bit set to solicit an acknowledgement from the receiver.
11. MAX_I_LEN is the maximum size of an LLC2 I-frame. LLC2 requires all incoming I-frames above a certain size to be rejected by a FRMR. This parameter specifies the maximum size of data that may bereceived starint from the LLC2 protocol header.

    In an X.25 network, it is constructed as (maximum X.25 data length + X.25 protool header length + LLC2 protocol header length). In an SNA network, it is constructed as (maximum SNA data length + SNA request header length + SNA transmission header length + LLC2 protocol header length).

12. XID_WINDOW is the XID window size (receive window), when the remote window size is unknown or zero.
13. XID_NDUP is the duplicate MAC XID count (0 means no test).
14. XID_TDUP is the duplicate MAC XID time. The value is in units of 0.1 seconds.

Files

Files following this format are normally kept in the /etc/sysconfig/strx25/template/ directory.¹⁸

See Also

• lltune(8)
• llc2(4)
• x25netd(8)

Compatibility

The llc2template file format is compatible with Spider X.25, and implementations based on Spider X.25, such as AIXlink/X.25, HP-UX, IRIS SX.25, Solstice X.25, PT X.25, SBE X.25, with the following compatibility considerations:

• PT X.25 does not support LLC2. OpenSS7 X.25 Networking supports LLC2 in support of XOL and porting applications from AIXlink/X.25, Solstice X.25, HP-UX, IRIS SX.25, VxWorks, pSOS, SpiderX, and many other implementations based on SpiderX.25 support LLC2. Portable X.25 and XOL applications will use OpenSS7 X.25 Networking instead of PT X.25.

Conformance

AIXlink/X.25, HP-UX, IRIS SX.25, Solstice X.25, PT X.25, SBE X.25, documentation.

History

The llc2template file format first appeared in Spider X.25.

9.3 mlptemplate File Format

The mlptemplate file format is documented in the mlptemplate(5) manual page.

Appendix A LLI Compatibility and Porting

A.1 Compatibility with AIXlink/X.25

A.2 Compatibility with HP X.25/9000

A.3 Compatibility with IRIS SX.25

A.4 Compatibility with PT X.25

A.5 Compatibility with RadiSys WAN

A.6 Compatibility with SBE X.25

A.7 Compatibility with Solstice X.25

Glossary of LLI Terms and Acronyms

References

Index

• dpkg(1): Footnotes
• dpkg(1): Footnotes
• getmsg(2s): Footnotes
• getpmsg(2): Footnotes
• hdlc(4): hdlc Driver
• I_LINK(7): Footnotes
• ioctl(2): Footnotes
• lapb(4): lapbtemplate File Format
• lapb(4): lapb Driver
• lapbtemplate(5): lapbtemplate File Format
• linkadd(8): linkadd Utility
• linkdel(8): linkdel Utility
• linklist(8): linklist Utility
• linkreset(8): linkreset Utility
• linkstart(8): linkstart Utility
• linkstate(8): linkstate Utility
• linkstop(8): linkstop Utility
• llc1(4): llc1 Driver
• llc2(4): llc2template File Format
• llc2(4): llc2 Driver
• llc2template(5): llc2template File Format
• lltune(8): llc2template File Format
• lltune(8): lapbtemplate File Format
• lltune(8): lltune Utility
• mlptemplate(5): mlptemplate File Format
• mlptune(8): mlptune Utility
• putmsg(2s): Footnotes
• putpmsg(2): Footnotes
• rpm(1): Footnotes
• rpm(1): Footnotes
• s_lli(4): s_lli Module
• s_llic(4): s_llic Module
• STREAMS(9): llc2template File Format
• STREAMS(9): lapbtemplate File Format
• x25netd(8): llc2template File Format
• x25netd(8): lapbtemplate File Format