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diff --git a/Documentation/networking/generic-hdlc.rst b/Documentation/networking/generic-hdlc.rst new file mode 100644 index 000000000..1c3bb5cb9 --- /dev/null +++ b/Documentation/networking/generic-hdlc.rst @@ -0,0 +1,170 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================== +Generic HDLC layer +================== + +Krzysztof Halasa <khc@pm.waw.pl> + + +Generic HDLC layer currently supports: + +1. Frame Relay (ANSI, CCITT, Cisco and no LMI) + + - Normal (routed) and Ethernet-bridged (Ethernet device emulation) + interfaces can share a single PVC. + - ARP support (no InARP support in the kernel - there is an + experimental InARP user-space daemon available on: + http://www.kernel.org/pub/linux/utils/net/hdlc/). + +2. raw HDLC - either IP (IPv4) interface or Ethernet device emulation +3. Cisco HDLC +4. PPP +5. X.25 (uses X.25 routines). + +Generic HDLC is a protocol driver only - it needs a low-level driver +for your particular hardware. + +Ethernet device emulation (using HDLC or Frame-Relay PVC) is compatible +with IEEE 802.1Q (VLANs) and 802.1D (Ethernet bridging). + + +Make sure the hdlc.o and the hardware driver are loaded. It should +create a number of "hdlc" (hdlc0 etc) network devices, one for each +WAN port. You'll need the "sethdlc" utility, get it from: + + http://www.kernel.org/pub/linux/utils/net/hdlc/ + +Compile sethdlc.c utility:: + + gcc -O2 -Wall -o sethdlc sethdlc.c + +Make sure you're using a correct version of sethdlc for your kernel. + +Use sethdlc to set physical interface, clock rate, HDLC mode used, +and add any required PVCs if using Frame Relay. +Usually you want something like:: + + sethdlc hdlc0 clock int rate 128000 + sethdlc hdlc0 cisco interval 10 timeout 25 + +or:: + + sethdlc hdlc0 rs232 clock ext + sethdlc hdlc0 fr lmi ansi + sethdlc hdlc0 create 99 + ifconfig hdlc0 up + ifconfig pvc0 localIP pointopoint remoteIP + +In Frame Relay mode, ifconfig master hdlc device up (without assigning +any IP address to it) before using pvc devices. + + +Setting interface: + +* v35 | rs232 | x21 | t1 | e1 + - sets physical interface for a given port + if the card has software-selectable interfaces + loopback + - activate hardware loopback (for testing only) +* clock ext + - both RX clock and TX clock external +* clock int + - both RX clock and TX clock internal +* clock txint + - RX clock external, TX clock internal +* clock txfromrx + - RX clock external, TX clock derived from RX clock +* rate + - sets clock rate in bps (for "int" or "txint" clock only) + + +Setting protocol: + +* hdlc - sets raw HDLC (IP-only) mode + + nrz / nrzi / fm-mark / fm-space / manchester - sets transmission code + + no-parity / crc16 / crc16-pr0 (CRC16 with preset zeros) / crc32-itu + + crc16-itu (CRC16 with ITU-T polynomial) / crc16-itu-pr0 - sets parity + +* hdlc-eth - Ethernet device emulation using HDLC. Parity and encoding + as above. + +* cisco - sets Cisco HDLC mode (IP, IPv6 and IPX supported) + + interval - time in seconds between keepalive packets + + timeout - time in seconds after last received keepalive packet before + we assume the link is down + +* ppp - sets synchronous PPP mode + +* x25 - sets X.25 mode + +* fr - Frame Relay mode + + lmi ansi / ccitt / cisco / none - LMI (link management) type + + dce - Frame Relay DCE (network) side LMI instead of default DTE (user). + + It has nothing to do with clocks! + + - t391 - link integrity verification polling timer (in seconds) - user + - t392 - polling verification timer (in seconds) - network + - n391 - full status polling counter - user + - n392 - error threshold - both user and network + - n393 - monitored events count - both user and network + +Frame-Relay only: + +* create n | delete n - adds / deletes PVC interface with DLCI #n. + Newly created interface will be named pvc0, pvc1 etc. + +* create ether n | delete ether n - adds a device for Ethernet-bridged + frames. The device will be named pvceth0, pvceth1 etc. + + + + +Board-specific issues +--------------------- + +n2.o and c101.o need parameters to work:: + + insmod n2 hw=io,irq,ram,ports[:io,irq,...] + +example:: + + insmod n2 hw=0x300,10,0xD0000,01 + +or:: + + insmod c101 hw=irq,ram[:irq,...] + +example:: + + insmod c101 hw=9,0xdc000 + +If built into the kernel, these drivers need kernel (command line) parameters:: + + n2.hw=io,irq,ram,ports:... + +or:: + + c101.hw=irq,ram:... + + + +If you have a problem with N2, C101 or PLX200SYN card, you can issue the +"private" command to see port's packet descriptor rings (in kernel logs):: + + sethdlc hdlc0 private + +The hardware driver has to be build with #define DEBUG_RINGS. +Attaching this info to bug reports would be helpful. Anyway, let me know +if you have problems using this. + +For patches and other info look at: +<http://www.kernel.org/pub/linux/utils/net/hdlc/>. |