ACC HDLC/LAP-D Protocol User’s Guide Edition 4 HP 9000 EISA Computers Manufacturing Part Number: Z7487-90006 E0400 © Copyright 2000 Hewlett-Packard Company
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Preface The HDLC/LAP-D Protocol Product is used in conjunction with HewlettPackard’s Advanced Communications Controller (ACC) product. Specifically this protocol applies only to the E1/T1 4-port multiplexer cards (Z7300A etc.) This manual applies to the ACC Protocols for Application Developers product. This manual explains installing the HDLC/LAP-D protocol module and configuring it into the ACC product.
Publishing History The Printing History below identifies the edition of this manual and any updates that are included. Periodically, update packages are distributed which contain replacement pages to be merged into the manual, including an updated copy of this printing history page. Also, the update may contain write-in instructions. Each reprinting of this manual will incorporate all past updates; however, no new information will be added.
Organization This manual contains the following chapters and appendices: Chapter 1 Introduction - presents an overview of the features provided by the HDLC/LAP-D Protocol product. Chapter 2 Software Installation and Verification - describes how to install the protocol module software. It describes how to verify that the protocol software is correctly installed and is functional.
Related Documentation The documentation available for the Multiprotocol ACC family of products includes the following hardware and software manuals: Hardware Manuals • 8 Channel HP-PB ACC Multiplexer Hardware Installation and Reference Manual • 8 Channel EISA ACC Multiplexer Hardware Installation and Reference Manual • 8 Channel PCI ACC Multiplexer Hardware Installation and Reference Manual • 2 Channel (HP-PB) ACC Multiplexer Hardware Installation and Reference Manual • 4-Chan.
Contents 1. Overview Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Product Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Supported Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 2.
Contents Received Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Status and Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Terminal Request Status Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Unsolicited Status Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Write Completion Status Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 Overview 11
Overview Introduction Introduction The HDLC/LAP-D Protocol product is the Data Link or Level 2 layer used in conjunction with the Advanced Communications Controller (ACC) product. This manual provides installation and configuration information that is specific to the HDLC/LAP-D protocol. NOTE The ACC HDLC/LAP-D Protocol product currently runs only on the 4-channel E1/T1 Multiprotocol ACC card. Product Features The LAP-D (Link Access Procedure - D Channel) protocol is defined in ITU-T Recommendation Q.
Overview References References For information on installing the ACC product and how to start up the ACC Subsystem, refer to the ACC Installation and Configuration Guide. For information on use of the ZCOM Programmatic Interface, refer to the ACC Programmer’s Reference Guide. For information on using the utilities related to the ACC products, refer to the ACC Utilities Reference Guide. For information on error messages related to the ACC products, refer to the ACC Error Guide.
Overview References 14 Chapter 1
2 Software Installation and Verification 15
Software Installation and Verification Introduction Introduction The HDLC/LAP-D protocol is included in the ACC Developer Software Suite product. This chapter describes how to install the product using the swinstall utility. It also describes how to verify that the protocol has been successfully installed and is functional.
Software Installation and Verification Software Removal Software Removal If a previous version of the HDLC/LAP-D protocol product is already on the HP-UX system, it should first be removed. CAUTION It is very important to follow the instructions provided with the software that is currently installed in the system to shutdown and remove that software. This procedure may change between major releases of the product. Step 1. Log in to the system as superuser. Step 2.
Software Installation and Verification Software Installation Software Installation Running Swinstall The ACC software is read from the HP-UX Application CD-ROM, in superuser mode, using the swinstall utility. The steps are shown below. Step 1. Log in to the system as “root”. Step 2. Place the media in a local or remote CD-ROM drive. Step 3. Run swinstall, which behaves the same in the GUI interface as for the terminal interface.
Software Installation and Verification Product Identification Product Identification The what utility can be run on /opt/acc//lapd.zabs. to show what version of the protocols is installed.
Software Installation and Verification Installation Verification Installation Verification A sample configuration file /opt/acc/cfg/lapd_4ch_sample.answ file is provided with the ACC Developer Software Suite product. This sample file can be used to verify that the HDLC/LAP-D protocol module has been properly installed and is functional. Note that you need to customize this file, to reflect the location of the mux card(s) and to reflect the mux ports to be used. (The lapd_4ch_sample.
Software Installation and Verification Installation Verification For the test described here, the ports that will be logically connected together must have one port configured as DTE, and the other as DCE. NOTE Run ttgen on the .answ file. % ttgen -o lapd_4ch_sample.answ lapd_4ch_sample.tmem ttgen: END$ 0 Disasters, 0 Errors, 0 Warnings % Step 3. Bring up the ZCOM subsystem: % zmasterd cold /opt/acc/cfg/lapd_4ch_sample.tmem Step 4.
Software Installation and Verification Installation Verification Step 6. The link can now be enabled and brought up using the zterm utility: % zterm 11:34:46 ZCOM Interactive command utility 11:34:46 Primary ZLU is 1001 ZTERM> rc 600 601 ZTERM> cn 600 601 en ZTERM> cn 600 601 ac ZTERM> ex % Step 7. The zmntr utility can be used to observe the state of the link: % zmntr ZMNTR> tt 600 601 ZLU# Mx p:sc Terminal Description...
Software Installation and Verification Installation Verification Step 9. The received data can now be displayed: ZTERM> rx list 11:49:49 Msg from tmnl ZLU#00601(00123) Lcn .00. .01. .02. .03. .04. .05. .06. 000 5A74 3031 3739 3800 206D 6573 7361 010 2030 3030 3031 206C 656E 6774 6820 020 6F70 7172 7374 7576 7758 len 50 No error detected .07. .08. .09. ASCII.....ASCII..... 6765 206E 6F2E Zt01798 message no. 2020 2035 3024 00001 length 50$ opqrstuvwX 11:49:49 Msg from tmnl ZLU#00601(00123) Lcn .00. .01. .
Software Installation and Verification Installation Verification 24 Chapter 2
3 Using HDLC/LAP-D Protocol 25
Using HDLC/LAP-D Protocol Introduction Introduction For a complete description of the communication formats the reader is referred to the standards documents mentioned at the start of this manual. Each unit transmitted over an HDLC/LAP-D link is a “frame”. A frame has a header and a trailing CRC, is preceded and followed by a flag byte (binary 01111110), and may include an “I” (information) field as well. Frames may be information transfer, supervisory or unnumbered.
Using HDLC/LAP-D Protocol General Protocol Processing General Protocol Processing Application Message Headers All application data is transmitted (or received) as the I-field of either an information transfer frame or an unnumbered information frame. All headers and/or trailers are supplied by the protocol for outgoing messages and removed by the protocol for incoming messages.
Using HDLC/LAP-D Protocol General Protocol Processing Timeout Processing Frame timeouts are set in the Select configuration word. The T200 timer defines the period within which a response to a Command frame must be received across the HDLC/LAP-D link. Should this timer expire before the expected response is received, then the Command frame will be re-transmitted up to a pre-determined maximum number of times. The maximum number of re-transmissions (N200) is also set by the Select configuration word.
Using HDLC/LAP-D Protocol Request Specific Processing Request Specific Processing Terminal Enable/Disable Requests Enabling a non-UI terminal causes the protocol to attempt to enter multiple frame acknowledged operation (the state that allows Information frames to be exchanged). Disabling a terminal causes the non-UI terminal to exit multiple frame acknowledged operation. A newly created terminal is initially disabled.
Using HDLC/LAP-D Protocol Request Specific Processing Control Requests All control writes to this protocol share a common format. The first four bytes are defined as a header: 15 14 13 12 Control Code 11 10 9 8 7 6 5 4 3 2 1 0 Control Length Packet Length Control Code Defines the action to be taken by this request. Control Length The length of the data for this control request. This data immediately follows the header.
Using HDLC/LAP-D Protocol Request Specific Processing 7 CW_TIMERS Set timers This request is only allowed for non-UI terminals. The protocol’s timers may be changed from their configured values using this control write. This request should be used with caution because the values configured with this request will not be restored if the card is reset by ZCOM. The control request data consists of three pairs of bytes. Each pair of bytes consists of a Resolution and a Value.
Using HDLC/LAP-D Protocol Status and Error Messages Status and Error Messages HDLC/LAP-D produces a range of buffer status codes and unsolicited status messages, apart from the standard communications statuses described elsewhere in the ACC documentation. In the following descriptions, the statuses marked with a dagger (†) are not generated by UI terminals. The defines for these status codes are located in /usr/include/zcom/zcomstatus.h and /usr/include/zcom/zx25status.h.
Using HDLC/LAP-D Protocol Status and Error Messages 14 TM_TABLE_SIZE Protocol table sizes too small The configured terminal table size is too small to allow LAP-D to run. This status is returned in response to a terminal creation request. Unsolicited Status Messages This section describe the unsolicited status messages which may be received on the ZLU which is set as the receiver for a terminal using this protocol. The status codes received may or may not have bit 7 set.
Using HDLC/LAP-D Protocol Status and Error Messages 64 ST25ENBL† Link NOT established on ENABLE This status message is generated in response to a terminal enable request after it is determined that multiple frame acknowledged operation can not be established. The down bit will always be set. 65 ST25DSBL Link disconnected on DISABLE This status message is generated in response to a terminal disable request after multiple frame acknowledged operation has terminated. The down bit will always be set.
Using HDLC/LAP-D Protocol Status and Error Messages 69 ST25TXFR† Reset/Disc. due to transmitted FRMR An unrecognized frame was received by the protocol; this causes LAP-D to reset the link by sending a SABME. For consistent error handling between LAP-D and LAP-B (which sends a FRMR instead of a SABME), the protocol sends this status message. The data buffer contains the information field of the FRMR that LAP-B would send. 70 ST25RXFR† Reset/Disc.
Using HDLC/LAP-D Protocol Status and Error Messages 89 ST25REVCD Revision code upload This message is sent in response to a CW_REVCODE control write. The data buffer contains a single byte which is the current protocol version. Currently, this is 11. Write Completion Status Codes The following statuses are returned in response to write requests. Although these are a part of the standard status set, they are not used by all protocols, and have a particular significance within this protocol.
Using HDLC/LAP-D Protocol Status and Error Messages 1 IO_DSBL Terminal disabled The terminal must be enabled before it will accept write or control write requests. 11 IO_LONG_MSG Message too long Indicates one of the following errors: • • • 12 IO_SHRT_MSG The packet length in the header is not zero. The control length in the header is not zero for a CW_STATS or CW_REVCODE request. The control length in the header is greater than six for a CW_TIMERS request.
Using HDLC/LAP-D Protocol Status and Error Messages 38 Chapter 3
4 Protocol Specific Configuration 39
Protocol Specific Configuration Introduction Introduction This section provides specific information on preparing the network configuration file when HDLC/LAP-D is to be used.The parts of the network configuration answer file relevant to HDLC/LAP-D are: • Interface-Definition • Port-Definition • Subchannel-Definition • Terminal-Definition Interface-Definition An ACC Interface-Definition line appears in the configuration file for each ACC card that will have LAP-D connections configured on it.
Protocol Specific Configuration Subchannel-Definition Subchannel-Definition This field is for cards that support subchannels. A sample Subchannel-Definition for the 4-channel T1/E1 card using eight timeslots is as follows: Subch 01:4:01 HDLC INV=off ITBS=2 ts:01:FFh ts:02:FFh ~ ts:03:FFh ts:04:FFh ts:05:FFh ts:06:FFh ts:07:FFh ts:08:FFh Refer to the ACC Utilities Reference Guide section on ttgen for details.
Protocol Specific Configuration Terminal-Definition Terminal-Definition Each HDLC/LAP-D Mux channel requires one (and only one) Terminal-Definition for the HDLC/LAP-D point-to-point link. The LAP-D terminal is defined by a Terminal-Definition line in the ZCOM network answer file (-.answ). Some sample HDLC/LAP-D Terminal-Definition lines for the Z7300A card follow: Term 120 Option 0000h Term 120 Option 0000h 1:6:3 LAPD.DLE 0008h 1:6:3 LAPD.
Protocol Specific Configuration Terminal-Definition mux:port:subc The port assigned must be configured as above and the ACC card must have the appropriate HDLC/LAP-D firmware configured. You must also have defined the subchannel number in the Subchannel definition section. dtype The device type of the HDLC/LAP-D terminal must be LAPD.DLE. poll/select This supplies the “POLL” and “SELECT” parameters for the ZCOM Terminal-Definition.
Protocol Specific Configuration Terminal-Definition application and can be set to any value desired. They can be accessed by the application from the Logical Terminal Table using ZINFO(). name Choose a meaningful description of the LAP-D link, preferably including a reference to the location of the remote end of the link. This field will be used in some ZMNTR displays. It may also be accessed programmatically using the ZINFO call.
Protocol Specific Configuration Predefined Configuration Values Predefined Configuration Values The following configuration values are currently defined for use in HDLC/LAP-D configuration as a replacement for the POLL and SELECT address fields. These values are used (for example HDLC_DTE_3.0) as a symbolic way of configuring the associated two 16-bit hexadecimal values.
Protocol Specific Configuration Poll/Select/Option Configuration Values Poll/Select/Option Configuration Values The following parameters for configurable for HDLC/LAP-D links: SAPI The Service Access Point Identifier TEI The Terminal Endpoint Identifier U/N Operating mode - User or Network side K Number of outstanding I frames N200 Number of retransmissions allowed N201 Largest I-field allowed (in bytes) T200 Acknowledgment Timer T203 Idle line Timer UI Unnumbered Information terminal T20
Protocol Specific Configuration Poll/Select/Option Configuration Values Val Res Minimum Timeout Maximum Timeout 1 2 31 1 4 31 1 8 31 1 16 31 10 msec 10 msec 10 msec 100 msec 100 msec 100 msec 1 sec 1 sec 1 sec 10 sec 10 sec 10 sec 10 msec 30 msec 610 msec 100 msec 300 msec 6100 msec 1 sec 15 sec 61 sec 10 sec 310 sec 610 sec 20 msec 40 msec 620 msec 200 msec 400 msec 6200 msec 2 sec 16 sec 62 sec 20 sec 320 sec 620 sec When choosing values for timers, it is preferable to choose the resolution that
Protocol Specific Configuration Poll/Select/Option Configuration Values Select Word 15 14 T200 Res 13 12 11 10 T200 Val (I-63) 9 8 7 6 K (0-7) 5 4 3 2 1 0 N200 (1-31) T200 Val This is the value of the T200 Acknowledgment timer divided by two. The valid range for this field is 1 to 63 which translates to T200 timer values of 2 to 126. 0 is not allowed and is an error. The units of this timer are given by the T200 Res (resolution) field (see below).
Protocol Specific Configuration Poll/Select/Option Configuration Values First Option Word 15 14 13 12 11 10 9 T203 Res T203/2 Val (0-63) 8 7 6 5 4 3 IUF LargeK (0-127) 2 1 0 T203 Val This is the value of the T203 Idle line timer divided by two. Setting this field from 1 to 63 translates to T203 timer values of 2 to 126. The units of this timer are given by the T203 Res (resolution) field (see below).
Protocol Specific Configuration Poll/Select/Option Configuration Values Second Option Word 15 0 14 13 SAPI 12 11 10 9 8 7 6 0 TEI 5 4 3 2 1 0 Unused - should always be zero. SAPI The Service Access Point Identifier. TEI This value is used as the Terminal Endpoint Identifier.
A Sample Configuration Files 51
Sample Configuration Files Sample Network Configuration File Sample Network Configuration File The file shown below is the sample network configuration file that is provided with the HDLC/LAP-D protocol product.
Sample Configuration Files Sample Network Configuration File ts:18:FFh ts:19:FFh ts:20:FFh ts:21:FFh ts:22:FFh ~ ts:23:FFh ts:24:FFh ts:25:FFh ts:26:FFh ts:27:FFh ~ ts:28:FFh ts:29:FFh ts:30:FFh ts:31:FFh * Mux 0, port 1, subchan 01, timeslot 1 Subch 0:1:01 HDLC INV=off ITBS=2 ~ ts:01:FFh * Mux 0, port 1, subchan 02, timeslot 2 to 7 Subch 0:1:02 HDLC INV=off ITBS=12 ~ ts:02:FFh ts:03:FFh ts:04:FFh ts:05:FFh ts:06:FFh ts:07:FFh * Mux 0, port 1, subchan 03, timeslot 8 to 31 Subch 0:1:03 HDLC INV=off ITBS
Sample Configuration Files Sample Network Configuration File 54 Appendix A
