171 lines
4.4 KiB
ReStructuredText
171 lines
4.4 KiB
ReStructuredText
.. 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/>.
|