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Diffstat (limited to 'Documentation/networking/generic-hdlc.txt')
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diff --git a/Documentation/networking/generic-hdlc.txt b/Documentation/networking/generic-hdlc.txt new file mode 100644 index 000000000000..7d1dc6b884f3 --- /dev/null +++ b/Documentation/networking/generic-hdlc.txt @@ -0,0 +1,131 @@ +Generic HDLC layer +Krzysztof Halasa <khc@pm.waw.pl> +January, 2003 + + +Generic HDLC layer currently supports: +- Frame Relay (ANSI, CCITT and no LMI), with ARP support (no InARP). + Normal (routed) and Ethernet-bridged (Ethernet device emulation) + interfaces can share a single PVC. +- raw HDLC - either IP (IPv4) interface or Ethernet device emulation. +- Cisco HDLC, +- PPP (uses syncppp.c), +- X.25 (uses X.25 routines). + +There are hardware drivers for the following cards: +- C101 by Moxa Technologies Co., Ltd. +- RISCom/N2 by SDL Communications Inc. +- and others, some not in the official kernel. + +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://hq.pm.waw.pl/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 - external clock (uses DTE RX and TX clock) +* clock int - internal clock (provides clock signal on DCE clock output) +* clock txint - TX internal, RX external (provides TX clock on DCE output) +* clock txfromrx - TX clock derived from RX clock (TX clock on DCE output) +* rate - sets clock rate in bps (not required for external clock or + for txfromrx) + +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 / 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 or C101 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 CONFIG_HDLC_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://hq.pm.waw.pl/hdlc/ |