1$Id: INTERFACE,v 1.1.1.1 2007-08-03 18:51:31 rnuti Exp $ 2 3Description of the Interface between Linklevel and Hardwarelevel 4 of isdn4linux: 5 6 7 The Communication between Linklevel (LL) and Hardwarelevel (HL) 8 is based on the struct isdn_if (defined in isdnif.h). 9 10 An HL-driver can register itself at LL by calling the function 11 register_isdn() with a pointer to that struct. Prior to that, it has 12 to preset some of the fields of isdn_if. The LL sets the rest of 13 the fields. All further communication is done via callbacks using 14 the function-pointers defined in isdn_if. 15 16 Changes/Version numbering: 17 18 During development of the ISDN subsystem, several changes have been 19 made to the interface. Before it went into kernel, the package 20 had a unique version number. The last version, distributed separately 21 was 0.7.4. When the subsystem went into kernel, every functional unit 22 got a separate version number. These numbers are shown at initialization, 23 separated by slashes: 24 25 c.c/t.t/n.n/p.p/a.a/v.v 26 27 where 28 29 c.c is the revision of the common code. 30 t.t is the revision of the tty related code. 31 n.n is the revision of the network related code. 32 p.p is the revision of the ppp related code. 33 a.a is the revision of the audio related code. 34 v.v is the revision of the V.110 related code. 35 36 Changes in this document are marked with '***CHANGEx' where x representing 37 the version number. If that number starts with 0, it refers to the old, 38 separately distributed package. If it starts with one of the letters 39 above, it refers to the revision of the corresponding module. 40 ***CHANGEIx refers to the revision number of the isdnif.h 41 421. Description of the fields of isdn_if: 43 44 int channels; 45 46 This field has to be set by the HL-driver to the number of channels 47 supported prior to calling register_isdn(). Upon return of the call, 48 the LL puts an id there, which has to be used by the HL-driver when 49 invoking the other callbacks. 50 51 int maxbufsize; 52 53 ***CHANGE0.6: New since this version. 54 55 Also to be preset by the HL-driver. With this value the HL-driver 56 tells the LL the maximum size of a data-packet it will accept. 57 58 unsigned long features; 59 60 To be preset by the HL-driver. Using this field, the HL-driver 61 announces the features supported. At the moment this is limited to 62 report the supported layer2 and layer3-protocols. For setting this 63 field the constants ISDN_FEATURE..., declared in isdnif.h have to be 64 used. 65 66 ***CHANGE0.7.1: The line type (1TR6, EDSS1) has to be set. 67 68 unsigned short hl_hdrlen; 69 70 ***CHANGE0.7.4: New field. 71 72 To be preset by the HL-driver, if it supports sk_buff's. The driver 73 should put here the amount of additional space needed in sk_buff's for 74 its internal purposes. Drivers not supporting sk_buff's should 75 initialize this field to 0. 76 77 void (*rcvcallb_skb)(int, int, struct sk_buff *) 78 79 ***CHANGE0.7.4: New field. 80 81 This field will be set by LL. The HL-driver delivers received data- 82 packets by calling this function. Upon calling, the HL-driver must 83 already have its private data pulled off the head of the sk_buff. 84 85 Parameter: 86 int driver-Id 87 int Channel-number locally to the driver. (starting with 0) 88 struct sk_buff * Pointer to sk_buff, containing received data. 89 90 int (*statcallb)(isdn_ctrl*); 91 92 This field will be set by LL. This function has to be called by the 93 HL-driver for signaling status-changes or other events to the LL. 94 95 Parameter: 96 isdn_ctrl* 97 98 The struct isdn_ctrl also defined in isdn_if. The exact meanings of its 99 fields are described together with the descriptions of the possible 100 events. Here is only a short description of the fields: 101 102 driver = driver Id. 103 command = event-type. (one of the constants ISDN_STAT_...) 104 arg = depends on event-type. 105 num = depends on event-type. 106 107 Returnvalue: 108 0 on success, else -1 109 110 int (*command)(isdn_ctrl*); 111 112 This field has to be preset by the HL-driver. It points to a function, 113 to be called by LL to perform functions like dialing, B-channel 114 setup, etc. The exact meaning of the parameters is described with the 115 descriptions of the possible commands. 116 117 Parameter: 118 isdn_ctrl* 119 driver = driver-Id 120 command = command to perform. (one of the constants ISDN_CMD_...) 121 arg = depends on command. 122 num = depends on command. 123 124 Returnvalue: 125 >=0 on success, else error-code (-ENODEV etc.) 126 127 int (*writebuf_skb)(int, int, int, struct sk_buff *) 128 129 ***CHANGE0.7.4: New field. 130 ***CHANGEI.1.21: New field. 131 132 This field has to be preset by the HL-driver. The given function will 133 be called by the LL for delivering data to be send via B-Channel. 134 135 136 Parameter: 137 int driver-Id ***CHANGE0.7.4: New parameter. 138 int channel-number locally to the HL-driver. (starts with 0) 139 int ack ***ChangeI1.21: New parameter 140 If this is !0, the driver has to signal the delivery 141 by sending an ISDN_STAT_BSENT. If this is 0, the driver 142 MUST NOT send an ISDN_STAT_BSENT. 143 struct sk_buff * Pointer to sk_buff containing data to be send via 144 B-channel. 145 146 Returnvalue: 147 Length of data accepted on success, else error-code (-EINVAL on 148 oversized packets etc.) 149 150 int (*writecmd)(u_char*, int, int, int, int); 151 152 This field has to be preset by the HL-driver. The given function will be 153 called to perform write-requests on /dev/isdnctrl (i.e. sending commands 154 to the card) The data-format is hardware-specific. This function is 155 intended for debugging only. It is not necessary for normal operation 156 and never will be called by the tty-emulation- or network-code. If 157 this function is not supported, the driver has to set NULL here. 158 159 Parameter: 160 u_char* pointer to data. 161 int length of data. 162 int flag: 0 = call from within kernel-space. (HL-driver must use 163 memcpy, may NOT use schedule()) 164 1 = call from user-space. (HL-driver must use 165 memcpy_fromfs, use of schedule() allowed) 166 int driver-Id. 167 int channel-number locally to the HL-driver. (starts with 0) 168 169***CHANGEI1.14: The driver-Id and channel-number are new since this revision. 170 171 Returnvalue: 172 Length of data accepted on success, else error-code (-EINVAL etc.) 173 174 int (*readstat)(u_char*, int, int, int, int); 175 176 This field has to be preset by the HL-driver. The given function will be 177 called to perform read-requests on /dev/isdnctrl (i.e. reading replies 178 from the card) The data-format is hardware-specific. This function is 179 intended for debugging only. It is not necessary for normal operation 180 and never will be called by the tty-emulation- or network-code. If 181 this function is not supported, the driver has to set NULL here. 182 183 Parameter: 184 u_char* pointer to data. 185 int length of data. 186 int flag: 0 = call from within kernel-space. (HL-driver must use 187 memcpy, may NOT use schedule()) 188 1 = call from user-space. (HL-driver must use 189 memcpy_fromfs, use of schedule() allowed) 190 int driver-Id. 191 int channel-number locally to the HL-driver. (starts with 0) 192 193***CHANGEI1.14: The driver-Id and channel-number are new since this revision. 194 195 Returnvalue: 196 Length of data on success, else error-code (-EINVAL etc.) 197 198 char id[20]; 199 ***CHANGE0.7: New since this version. 200 201 This string has to be preset by the HL-driver. Its purpose is for 202 identification of the driver by the user. Eg.: it is shown in the 203 status-info of /dev/isdninfo. Furthermore it is used as Id for binding 204 net-interfaces to a specific channel. If a string of length zero is 205 given, upon return, isdn4linux will replace it by a generic name. (line0, 206 line1 etc.) It is recommended to make this string configurable during 207 module-load-time. (copy a global variable to this string.) For doing that, 208 modules 1.2.8 or newer are necessary. 209 2102. Description of the commands, a HL-driver has to support: 211 212 All commands will be performed by calling the function command() described 213 above from within the LL. The field command of the struct-parameter will 214 contain the desired command, the field driver is always set to the 215 appropriate driver-Id. 216 217 Until now, the following commands are defined: 218 219***CHANGEI1.34: The parameter "num" has been replaced by a union "parm" containing 220 the old "num" and a new setup_type struct used for ISDN_CMD_DIAL 221 and ISDN_STAT_ICALL callback. 222 223 ISDN_CMD_IOCTL: 224 225 This command is intended for performing ioctl-calls for configuring 226 hardware or similar purposes (setting port-addresses, loading firmware 227 etc.) For this purpose, in the LL all ioctl-calls with an argument 228 >= IIOCDRVCTL (0x100) will be handed transparently to this 229 function after subtracting 0x100 and placing the result in arg. 230 Example: 231 If a userlevel-program calls ioctl(0x101,...) the function gets 232 called with the field command set to 1. 233 234 Parameter: 235 driver = driver-Id. 236 command = ISDN_CMD_IOCTL 237 arg = Original ioctl-cmd - IIOCDRVCTL 238 parm.num = first bytes filled with (unsigned long)arg 239 240 Returnvalue: 241 Depending on driver. 242 243 244 ISDN_CMD_DIAL: 245 246 This command is used to tell the HL-driver it should dial a given 247 number. 248 249 Parameter: 250 driver = driver-Id. 251 command = ISDN_CMD_DIAL 252 arg = channel-number locally to the driver. (starting with 0) 253 254 parm.setup.phone = An ASCII-String containing the number to dial. 255 parm.setup.eazmsn = An ASCII-Sting containing the own EAZ or MSN. 256 parm.setup.si1 = The Service-Indicator. 257 parm.setup.si2 = Additional Service-Indicator. 258 259 If the Line has been designed as SPV (a special german 260 feature, meaning semi-leased-line) the phone has to 261 start with an "S". 262 ***CHANGE0.6: In previous versions the EAZ has been given in the 263 highbyte of arg. 264 ***CHANGE0.7.1: New since this version: ServiceIndicator and AddInfo. 265 266 ISDN_CMD_ACCEPTD: 267 268 With this command, the HL-driver is told to accept a D-Channel-setup. 269 (Response to an incoming call) 270 271 Parameter: 272 driver = driver-Id. 273 command = ISDN_CMD_ACCEPTD 274 arg = channel-number locally to the driver. (starting with 0) 275 parm = unused. 276 277 ISDN_CMD_ACCEPTB: 278 279 With this command, the HL-driver is told to perform a B-Channel-setup. 280 (after establishing D-Channel-Connection) 281 282 Parameter: 283 driver = driver-Id. 284 command = ISDN_CMD_ACCEPTB 285 arg = channel-number locally to the driver. (starting with 0) 286 parm = unused. 287 288 ISDN_CMD_HANGUP: 289 290 With this command, the HL-driver is told to hangup (B-Channel if 291 established first, then D-Channel). This command is also used for 292 actively rejecting an incoming call. 293 294 Parameter: 295 driver = driver-Id. 296 command = ISDN_CMD_HANGUP 297 arg = channel-number locally to the driver. (starting with 0) 298 parm = unused. 299 300 ISDN_CMD_CLREAZ: 301 302 With this command, the HL-driver is told not to signal incoming 303 calls to the LL. 304 305 Parameter: 306 driver = driver-Id. 307 command = ISDN_CMD_CLREAZ 308 arg = channel-number locally to the driver. (starting with 0) 309 parm = unused. 310 311 ISDN_CMD_SETEAZ: 312 313 With this command, the HL-driver is told to signal incoming calls for 314 the given EAZs/MSNs to the LL. 315 316 Parameter: 317 driver = driver-Id. 318 command = ISDN_CMD_SETEAZ 319 arg = channel-number locally to the driver. (starting with 0) 320 parm.num = ASCII-String, containing the desired EAZ's/MSN's 321 (comma-separated). If an empty String is given, the 322 HL-driver should respond to ALL incoming calls, 323 regardless of the destination-address. 324 ***CHANGE0.6: New since this version the "empty-string"-feature. 325 326 ISDN_CMD_GETEAZ: (currently unused) 327 328 With this command, the HL-driver is told to report the current setting 329 given with ISDN_CMD_SETEAZ. 330 331 Parameter: 332 driver = driver-Id. 333 command = ISDN_CMD_GETEAZ 334 arg = channel-number locally to the driver. (starting with 0) 335 parm.num = ASCII-String, containing the current EAZ's/MSN's 336 337 ISDN_CMD_SETSIL: (currently unused) 338 339 With this command, the HL-driver is told to signal only incoming 340 calls with the given Service-Indicators. 341 342 Parameter: 343 driver = driver-Id. 344 command = ISDN_CMD_SETSIL 345 arg = channel-number locally to the driver. (starting with 0) 346 parm.num = ASCII-String, containing the desired Service-Indicators. 347 348 ISDN_CMD_GETSIL: (currently unused) 349 350 With this command, the HL-driver is told to return the current 351 Service-Indicators it will respond to. 352 353 Parameter: 354 driver = driver-Id. 355 command = ISDN_CMD_SETSIL 356 arg = channel-number locally to the driver. (starting with 0) 357 parm.num = ASCII-String, containing the current Service-Indicators. 358 359 ISDN_CMD_SETL2: 360 361 With this command, the HL-driver is told to select the given Layer-2- 362 protocol. This command is issued by the LL prior to ISDN_CMD_DIAL or 363 ISDN_CMD_ACCEPTD. 364 365 366 Parameter: 367 driver = driver-Id. 368 command = ISDN_CMD_SETL2 369 arg = channel-number locally to the driver. (starting with 0) 370 logical or'ed with (protocol-Id << 8) 371 protocol-Id is one of the constants ISDN_PROTO_L2... 372 parm = unused. 373 374 ISDN_CMD_GETL2: (currently unused) 375 376 With this command, the HL-driver is told to return the current 377 setting of the Layer-2-protocol. 378 379 Parameter: 380 driver = driver-Id. 381 command = ISDN_CMD_GETL2 382 arg = channel-number locally to the driver. (starting with 0) 383 parm = unused. 384 Returnvalue: 385 current protocol-Id (one of the constants ISDN_L2_PROTO) 386 387 ISDN_CMD_SETL3: 388 389 With this command, the HL-driver is told to select the given Layer-3- 390 protocol. This command is issued by the LL prior to ISDN_CMD_DIAL or 391 ISDN_CMD_ACCEPTD. 392 393 394 Parameter: 395 driver = driver-Id. 396 command = ISDN_CMD_SETL3 397 arg = channel-number locally to the driver. (starting with 0) 398 logical or'ed with (protocol-Id << 8) 399 protocol-Id is one of the constants ISDN_PROTO_L3... 400 parm.fax = Pointer to T30_s fax struct. (fax usage only) 401 402 ISDN_CMD_GETL2: (currently unused) 403 404 With this command, the HL-driver is told to return the current 405 setting of the Layer-3-protocol. 406 407 Parameter: 408 driver = driver-Id. 409 command = ISDN_CMD_GETL3 410 arg = channel-number locally to the driver. (starting with 0) 411 parm = unused. 412 Returnvalue: 413 current protocol-Id (one of the constants ISDN_L3_PROTO) 414 415 ISDN_CMD_PROCEED: 416 417 With this command, the HL-driver is told to proceed with a incoming call. 418 419 Parameter: 420 driver = driver-Id. 421 command = ISDN_CMD_PROCEED 422 arg = channel-number locally to the driver. (starting with 0) 423 setup.eazmsn= empty string or string send as uus1 in DSS1 with 424 PROCEED message 425 426 ISDN_CMD_ALERT: 427 428 With this command, the HL-driver is told to alert a proceeding call. 429 430 Parameter: 431 driver = driver-Id. 432 command = ISDN_CMD_ALERT 433 arg = channel-number locally to the driver. (starting with 0) 434 setup.eazmsn= empty string or string send as uus1 in DSS1 with 435 ALERT message 436 437 ISDN_CMD_REDIR: 438 439 With this command, the HL-driver is told to redirect a call in proceeding 440 or alerting state. 441 442 Parameter: 443 driver = driver-Id. 444 command = ISDN_CMD_REDIR 445 arg = channel-number locally to the driver. (starting with 0) 446 setup.eazmsn= empty string or string send as uus1 in DSS1 protocol 447 setup.screen= screening indicator 448 setup.phone = redirected to party number 449 450 ISDN_CMD_PROT_IO: 451 452 With this call, the LL-driver invokes protocol specific features through 453 the LL. 454 The call is not implicitely bound to a connection. 455 456 Parameter: 457 driver = driver-Id 458 command = ISDN_CMD_PROT_IO 459 arg = The lower 8 Bits define the addressed protocol as defined 460 in ISDN_PTYPE..., the upper bits are used to differentiate 461 the protocol specific CMD. 462 463 para = protocol and function specific. See isdnif.h for detail. 464 465 466 ISDN_CMD_FAXCMD: 467 468 With this command the HL-driver receives a fax sub-command. 469 For details refer to INTERFACE.fax 470 471 Parameter: 472 driver = driver-Id. 473 command = ISDN_CMD_FAXCMD 474 arg = channel-number locally to the driver. (starting with 0) 475 parm = unused. 476 477 4783. Description of the events to be signaled by the HL-driver to the LL. 479 480 All status-changes are signaled via calling the previously described 481 function statcallb(). The field command of the struct isdn_cmd has 482 to be set by the HL-driver with the appropriate Status-Id (event-number). 483 The field arg has to be set to the channel-number (locally to the driver, 484 starting with 0) to which this event applies. (Exception: STAVAIL-event) 485 486 Until now, the following Status-Ids are defined: 487 488 ISDN_STAT_AVAIL: 489 490 With this call, the HL-driver signals the availability of new data 491 for readstat(). Used only for debugging-purposes, see description 492 of readstat(). 493 494 Parameter: 495 driver = driver-Id 496 command = ISDN_STAT_STAVAIL 497 arg = length of available data. 498 parm = unused. 499 500 ISDN_STAT_ICALL: 501 ISDN_STAT_ICALLW: 502 503 With this call, the HL-driver signals an incoming call to the LL. 504 If ICALLW is signalled the incoming call is a waiting call without 505 a available B-chan. 506 507 Parameter: 508 driver = driver-Id 509 command = ISDN_STAT_ICALL 510 arg = channel-number, locally to the driver. (starting with 0) 511 para.setup.phone = Callernumber. 512 para.setup.eazmsn = CalledNumber. 513 para.setup.si1 = Service Indicator. 514 para.setup.si2 = Additional Service Indicator. 515 para.setup.plan = octet 3 from Calling party number Information Element. 516 para.setup.screen = octet 3a from Calling party number Information Element. 517 518 Return: 519 0 = No device matching this call. 520 1 = At least one device matching this call (RING on ttyI). 521 HL-driver may send ALERTING on the D-channel in this case. 522 2 = Call will be rejected. 523 3 = Incoming called party number is currently incomplete. 524 Additional digits are required. 525 Used for signalling with PtP connections. 526 4 = Call will be held in a proceeding state 527 (HL driver sends PROCEEDING) 528 Used when a user space prog needs time to interpret a call 529 para.setup.eazmsn may be filled with an uus1 message of 530 30 octets maximum. Empty string if no uus. 531 5 = Call will be actively deflected to another party 532 Only available in DSS1/EURO protocol 533 para.setup.phone must be set to destination party number 534 para.setup.eazmsn may be filled with an uus1 message of 535 30 octets maximum. Empty string if no uus. 536 -1 = An error happened. (Invalid parameters for example.) 537 The keypad support now is included in the dial command. 538 539 540 ISDN_STAT_RUN: 541 542 With this call, the HL-driver signals availability of the ISDN-card. 543 (after initializing, loading firmware) 544 545 Parameter: 546 driver = driver-Id 547 command = ISDN_STAT_RUN 548 arg = unused. 549 parm = unused. 550 551 ISDN_STAT_STOP: 552 553 With this call, the HL-driver signals unavailability of the ISDN-card. 554 (before unloading, while resetting/reconfiguring the card) 555 556 Parameter: 557 driver = driver-Id 558 command = ISDN_STAT_STOP 559 arg = unused. 560 parm = unused. 561 562 ISDN_STAT_DCONN: 563 564 With this call, the HL-driver signals the successful establishment of 565 a D-Channel-connection. (Response to ISDN_CMD_ACCEPTD or ISDN_CMD_DIAL) 566 567 Parameter: 568 driver = driver-Id 569 command = ISDN_STAT_DCONN 570 arg = channel-number, locally to the driver. (starting with 0) 571 parm = unused. 572 573 ISDN_STAT_BCONN: 574 575 With this call, the HL-driver signals the successful establishment of 576 a B-Channel-connection. (Response to ISDN_CMD_ACCEPTB or because the 577 remote-station has initiated establishment) 578 579 The HL driver should call this when the logical l2/l3 protocol 580 connection on top of the physical B-channel is established. 581 582 Parameter: 583 driver = driver-Id 584 command = ISDN_STAT_BCONN 585 arg = channel-number, locally to the driver. (starting with 0) 586 parm.num = ASCII-String, containing type of connection (for analog 587 modem only). This will be appended to the CONNECT message 588 e.g. 14400/V.32bis 589 590 ISDN_STAT_DHUP: 591 592 With this call, the HL-driver signals the shutdown of a 593 D-Channel-connection. This could be a response to a prior ISDN_CMD_HANGUP, 594 or caused by a remote-hangup or if the remote-station has actively 595 rejected a call. 596 597 Parameter: 598 driver = driver-Id 599 command = ISDN_STAT_DHUP 600 arg = channel-number, locally to the driver. (starting with 0) 601 parm = unused. 602 603 ISDN_STAT_BHUP: 604 605 With this call, the HL-driver signals the shutdown of a 606 B-Channel-connection. This could be a response to a prior ISDN_CMD_HANGUP, 607 or caused by a remote-hangup. 608 609 The HL driver should call this as soon as the logical l2/l3 protocol 610 connection on top of the physical B-channel is released. 611 612 Parameter: 613 driver = driver-Id 614 command = ISDN_STAT_BHUP 615 arg = channel-number, locally to the driver. (starting with 0) 616 parm = unused. 617 618 ISDN_STAT_CINF: 619 620 With this call, the HL-driver delivers charge-unit information to the 621 LL. 622 623 Parameter: 624 driver = driver-Id 625 command = ISDN_STAT_CINF 626 arg = channel-number, locally to the driver. (starting with 0) 627 parm.num = ASCII string containing charge-units (digits only). 628 629 ISDN_STAT_LOAD: (currently unused) 630 631 ISDN_STAT_UNLOAD: 632 633 With this call, the HL-driver signals that it will be unloaded now. This 634 tells the LL to release all corresponding data-structures. 635 636 Parameter: 637 driver = driver-Id 638 command = ISDN_STAT_UNLOAD 639 arg = unused. 640 parm = unused. 641 642 ISDN_STAT_BSENT: 643 644 With this call the HL-driver signals the delivery of a data-packet. 645 This callback is used by the network-interfaces only, tty-Emulation 646 does not need this call. 647 648 Parameter: 649 driver = driver-Id 650 command = ISDN_STAT_BSENT 651 arg = channel-number, locally to the driver. (starting with 0) 652 parm.length = ***CHANGEI.1.21: New field. 653 the driver has to set this to the original length 654 of the skb at the time of receiving it from the linklevel. 655 656 ISDN_STAT_NODCH: 657 658 With this call, the driver has to respond to a prior ISDN_CMD_DIAL, if 659 no D-Channel is available. 660 661 Parameter: 662 driver = driver-Id 663 command = ISDN_STAT_NODCH 664 arg = channel-number, locally to the driver. (starting with 0) 665 parm = unused. 666 667 ISDN_STAT_ADDCH: 668 669 This call is for HL-drivers, which are unable to check card-type 670 or numbers of supported channels before they have loaded any firmware 671 using ioctl. Those HL-driver simply set the channel-parameter to a 672 minimum channel-number when registering, and later if they know 673 the real amount, perform this call, allocating additional channels. 674 675 Parameter: 676 driver = driver-Id 677 command = ISDN_STAT_ADDCH 678 arg = number of channels to be added. 679 parm = unused. 680 681 ISDN_STAT_CAUSE: 682 683 With this call, the HL-driver delivers CAUSE-messages to the LL. 684 Currently the LL does not use this messages. Their contents is simply 685 logged via kernel-messages. Therefore, currently the format of the 686 messages is completely free. However they should be printable. 687 688 Parameter: 689 driver = driver-Id 690 command = ISDN_STAT_NODCH 691 arg = channel-number, locally to the driver. (starting with 0) 692 parm.num = ASCII string containing CAUSE-message. 693 694 ISDN_STAT_DISPLAY: 695 696 With this call, the HL-driver delivers DISPLAY-messages to the LL. 697 Currently the LL does not use this messages. 698 699 Parameter: 700 driver = driver-Id 701 command = ISDN_STAT_DISPLAY 702 arg = channel-number, locally to the driver. (starting with 0) 703 para.display= string containing DISPLAY-message. 704 705 ISDN_STAT_PROT: 706 707 With this call, the HL-driver delivers protocol specific infos to the LL. 708 The call is not implicitely bound to a connection. 709 710 Parameter: 711 driver = driver-Id 712 command = ISDN_STAT_PROT 713 arg = The lower 8 Bits define the addressed protocol as defined 714 in ISDN_PTYPE..., the upper bits are used to differentiate 715 the protocol specific STAT. 716 717 para = protocol and function specific. See isdnif.h for detail. 718 719 ISDN_STAT_DISCH: 720 721 With this call, the HL-driver signals the LL to disable or enable the 722 use of supplied channel and driver. 723 The call may be used to reduce the available number of B-channels after 724 loading the driver. The LL has to ignore a disabled channel when searching 725 for free channels. The HL driver itself never delivers STAT callbacks for 726 disabled channels. 727 The LL returns a nonzero code if the operation was not successful or the 728 selected channel is actually regarded as busy. 729 730 Parameter: 731 driver = driver-Id 732 command = ISDN_STAT_DISCH 733 arg = channel-number, locally to the driver. (starting with 0) 734 parm.num[0] = 0 if channel shall be disabled, else enabled. 735 736 ISDN_STAT_L1ERR: 737 738 ***CHANGEI1.21 new status message. 739 A signal can be sent to the linklevel if an Layer1-error results in 740 packet-loss on receive or send. The field errcode of the cmd.parm 741 union describes the error more precisely. 742 743 Parameter: 744 driver = driver-Id 745 command = ISDN_STAT_L1ERR 746 arg = channel-number, locally to the driver. (starting with 0) 747 parm.errcode= ISDN_STAT_L1ERR_SEND: Packet lost while sending. 748 ISDN_STAT_L1ERR_RECV: Packet lost while receiving. 749 ISDN_STAT_FAXIND: 750 751 With this call the HL-driver signals a fax sub-command to the LL. 752 For details refer to INTERFACE.fax 753 754 Parameter: 755 driver = driver-Id. 756 command = ISDN_STAT_FAXIND 757 arg = channel-number, locally to the driver. (starting with 0) 758 parm = unused. 759 760