765 lines
23 KiB
Groff
765 lines
23 KiB
Groff
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.\" Copyright (c) 2002-2005 David Boggs. (boggs@boggs.palo-alto.ca.us)
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" BSD License:
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" GNU General Public License:
|
|
.\"
|
|
.\" This program is free software; you can redistribute it and/or modify it
|
|
.\" under the terms of the GNU General Public License as published by the Free
|
|
.\" Software Foundation; either version 2 of the License, or (at your option)
|
|
.\" any later version.
|
|
.\"
|
|
.\" This program is distributed in the hope that it will be useful, but WITHOUT
|
|
.\" ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
.\" FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
|
|
.\" more details.
|
|
.\"
|
|
.\" You should have received a copy of the GNU General Public License along with
|
|
.\" this program; if not, write to the Free Software Foundation, Inc., 59
|
|
.\" Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
.\"
|
|
.Dd February 8, 2012
|
|
.Dt LMC 4
|
|
.Os
|
|
.\"
|
|
.Sh NAME
|
|
.\"
|
|
.Nm lmc
|
|
.Nd device driver for
|
|
.Tn LMC
|
|
(now
|
|
.Tn SBE )
|
|
wide-area network interface cards
|
|
.\"
|
|
.Sh SYNOPSIS
|
|
.\"
|
|
To wire this driver into your kernel,
|
|
add the following line to your kernel configuration file:
|
|
.Bd -ragged -offset indent
|
|
.Cd "device lmc"
|
|
.Ed
|
|
.Pp
|
|
Alternatively, to load this module at boot time, add
|
|
.Bd -literal -offset indent
|
|
if_lmc_load="YES"
|
|
.Ed
|
|
.Pp
|
|
to
|
|
.Pa /boot/loader.conf ;
|
|
see
|
|
.Xr loader.conf 5 .
|
|
.Pp
|
|
To wire a line protocol into your kernel, add:
|
|
.Bd -ragged -offset indent
|
|
.Cd "options NETGRAPH"
|
|
.Cd "device sppp"
|
|
.Ed
|
|
.Pp
|
|
It is not necessary to wire line protocols into your kernel,
|
|
they can be loaded later with
|
|
.Xr kldload 8 .
|
|
The driver can send and receive raw IP packets even if neither
|
|
SPPP nor Netgraph are configured into the kernel.
|
|
Netgraph and SPPP can both be enabled; Netgraph will be used if the
|
|
.Va rawdata
|
|
hook is connected.
|
|
.\"
|
|
.Sh DESCRIPTION
|
|
.\"
|
|
This is an open-source
|
|
.Ux
|
|
device driver for PCI-bus WAN interface cards.
|
|
It sends and receives packets in HDLC frames over synchronous circuits.
|
|
A generic PC plus
|
|
.Ux
|
|
plus some
|
|
.Tn LMC / SBE
|
|
cards makes an
|
|
.Em open
|
|
router.
|
|
This driver works with
|
|
.Fx ,
|
|
.Nx ,
|
|
.Ox ,
|
|
.Bsx
|
|
and
|
|
.Tn Linux
|
|
OSs.
|
|
It has been tested on i386 (SMP 32-bit little-endian) and Sparc (64-bit big-endian)
|
|
architectures.
|
|
.Pp
|
|
The
|
|
.Nm
|
|
driver works with the following cards:
|
|
.Bl -bullet
|
|
.It
|
|
SBE wanADAPT-HSSI (LMC5200)
|
|
.Pp
|
|
High Speed Serial Interface,
|
|
EIA612/613, 50-pin connector,
|
|
0 to 52 Mb/s, DTE only.
|
|
.It
|
|
SBE wanADAPT-T3 (LMC5245)
|
|
.Pp
|
|
T3: two 75-ohm BNC connectors,
|
|
C-Parity or M13 Framing,
|
|
44.736 Mb/s, up to 950 ft.
|
|
.It
|
|
SBE wanADAPT-SSI (LMC1000)
|
|
.Pp
|
|
Synchronous Serial Interface,
|
|
V.35, X.21, EIA449, EIA530(A), EIA232,
|
|
0 to 10 Mb/s, DTE or DCE.
|
|
.It
|
|
SBE wanADAPT-T1E1 (LMC1200)
|
|
.Pp
|
|
T1 or E1: RJ45 conn, 100 or 120 ohms,
|
|
T1-ESF-B8ZS, T1-SF-AMI, E1-(many)-HDB3,
|
|
1.544 Mb/s or 2.048 Mb/s, up to 6 Kft.
|
|
.El
|
|
.Pp
|
|
Cards contain a high-performance
|
|
.Sy "PCI"
|
|
interface, an
|
|
.Sy "HDLC"
|
|
function and
|
|
either integrated
|
|
.Sy "modems"
|
|
(T1, T3) or
|
|
.Sy "modem"
|
|
interfaces (HSSI and SSI).
|
|
.Bl -tag -width "Modem"
|
|
.It Sy "PCI"
|
|
The PCI interface is a DEC 21140A "Tulip" Fast Ethernet chip.
|
|
This chip has an efficient PCI implementation with scatter/gather DMA,
|
|
and can run at 100 Mb/s full duplex (twice as fast as needed here).
|
|
.It Sy "HDLC"
|
|
The HDLC functions (ISO-3309: flags, bit-stuffing, CRC) are implemented
|
|
in a Field Programmable Gate Array (FPGA) which talks to the Ethernet
|
|
chip through a Media Independent Interface (MII).
|
|
The hardware in the FPGA translates between Ethernet packets and
|
|
HDLC frames on-the-fly; think it as a WAN PHY chip for Ethernet.
|
|
.It Sy "Modem"
|
|
The modem chips are the main differences between cards.
|
|
HSSI cards use ECL10K chips to implement the EIA-612/613 interface.
|
|
T3 cards use a TranSwitch TXC-03401 framer chip.
|
|
SSI cards use Linear Technology LTC1343 modem interface chips.
|
|
T1 cards use a BrookTree/Conexant/Mindspeed Bt8370 framer
|
|
and line interface chip.
|
|
.El
|
|
.Pp
|
|
Line protocols exist above device drivers and below internet protocols.
|
|
They typically encapsulate packets in HDLC frames and deal with
|
|
higher-level issues like protocol multiplexing and security.
|
|
This driver is compatible with several line protocol packages:
|
|
.Bl -tag -width "Generic HDLC"
|
|
.It Sy "Netgraph"
|
|
.Xr netgraph 4
|
|
implements many basic packet-handling functions as kernel loadable modules.
|
|
They can be interconnected in a graph to implement many protocols.
|
|
Configuration is done from userland without rebuilding the kernel.
|
|
Packets are sent and received through this interface if the driver's
|
|
.Em rawdata
|
|
hook is connected, otherwise the ifnet interface (SPPP and RawIP) is used.
|
|
ASCII configuration control messages are
|
|
.Em not
|
|
currently supported.
|
|
.It Sy "SPPP"
|
|
.Xr sppp 4
|
|
implements Synchronous-PPP, Frame-Relay and Cisco-HDLC in the kernel.
|
|
.It Sy "RawIP"
|
|
This null line protocol, built into the driver, sends and receives
|
|
raw IPv4 and IPv6 packets in HDLC frames (aka IP-in-HDLC) with
|
|
no extra bytes of overhead and no state at the end points.
|
|
.El
|
|
.\"
|
|
.Sh EXAMPLES
|
|
.\"
|
|
.Ss "ifconfig and lmcconfig"
|
|
.\"
|
|
The program
|
|
.Xr lmcconfig 8
|
|
manipulates interface parameters beyond the scope of
|
|
.Xr ifconfig 8 .
|
|
In normal operation only a few arguments are needed:
|
|
.Pp
|
|
.Bl -tag -width ".Fl X" -offset indent -compact
|
|
.It Fl X
|
|
selects the external
|
|
SPPP
|
|
line protocol package.
|
|
.It Fl x
|
|
selects the built-in RawIP line protocol package.
|
|
.It Fl Z
|
|
selects PPP line protocol.
|
|
.It Fl z
|
|
selects Cisco-HDLC line protocol.
|
|
.It Fl F
|
|
selects Frame-Relay line protocol.
|
|
.El
|
|
.Bl -tag -width indent
|
|
.It Li "lmcconfig lmc0"
|
|
displays interface configuration and status.
|
|
.It Li "lmcconfig lmc0 -D"
|
|
enables debugging output from the device driver only.
|
|
.It Li "ifconfig lmc0 debug"
|
|
enables debugging output from the device driver and from
|
|
the line protocol module above it.
|
|
Debugging messages that appear on the console are also
|
|
written to file
|
|
.Pa "/var/log/messages" .
|
|
.Em Caution :
|
|
when things go very wrong, a torrent of debugging messages
|
|
can swamp the console and bring a machine to its knees.
|
|
.El
|
|
.\"
|
|
.Ss Operation
|
|
.\"
|
|
Activate a PPP link using SPPP and Netgraph with:
|
|
.Bd -literal -offset indent
|
|
ngctl mkpeer lmc0: sppp rawdata downstream
|
|
ifconfig sppp0 10.0.0.1 10.0.0.2
|
|
.Ed
|
|
.Pp
|
|
Activate a PPP link using only SPPP with:
|
|
.Bd -literal -offset indent
|
|
lmcconfig lmc0 -XYZ
|
|
ifconfig lmc0 10.0.0.1 10.0.0.2
|
|
.Ed
|
|
.Pp
|
|
Activate a Cisco-HDLC link using SPPP and Netgraph with:
|
|
.Bd -literal -offset indent
|
|
ngctl mkpeer lmc0: sppp rawdata downstream
|
|
ifconfig sppp0 10.0.0.1 10.0.0.2 link2
|
|
.Ed
|
|
.Pp
|
|
Activate a Cisco-HDLC link using only SPPP with:
|
|
.Bd -literal -offset indent
|
|
lmcconfig lmc0 -XYz
|
|
ifconfig lmc0 10.0.0.1 10.0.0.2
|
|
.Ed
|
|
.Pp
|
|
Activate a Cisco-HDLC link using only Netgraph with:
|
|
.Bd -literal -offset indent
|
|
ngctl mkpeer lmc0: cisco rawdata downstream
|
|
ngctl mkpeer lmc0:rawdata iface inet inet
|
|
ifconfig ng0 10.0.0.1 10.0.0.2
|
|
.Ed
|
|
.Pp
|
|
Activate a Frame-Relay DTE link using SPPP with:
|
|
.Bd -literal -offset indent
|
|
lmcconfig lmc0 -XYF
|
|
ifconfig lmc0 10.0.0.1 10.0.0.2
|
|
.Ed
|
|
.Pp
|
|
(SPPP implements the ANSI T1.617 annex D LMI.)
|
|
.Pp
|
|
Activate a Frame-Relay DTE link using Netgraph with:
|
|
.Bd -literal -offset indent
|
|
ngctl mkpeer lmc0: frame_relay rawdata downstream
|
|
ngctl mkpeer lmc0:rawdata lmi dlci0 auto0
|
|
ngctl connect lmc0:rawdata dlci0 dlci1023 auto1023
|
|
ngctl mkpeer lmc0:rawdata rfc1490 dlci500 downstream
|
|
ngctl mkpeer lmc0:rawdata.dlci500 iface inet inet
|
|
ifconfig ng0 10.0.0.1 10.0.0.2
|
|
.Ed
|
|
This is
|
|
.Em ONE
|
|
possible Frame Relay configuration; there are many.
|
|
.Pp
|
|
Activate a RAWIP link using only the driver with:
|
|
.Bd -literal -offset indent
|
|
lmcconfig lmc0 -x
|
|
ifconfig lmc0 10.0.0.1 10.0.0.2
|
|
.Ed
|
|
.Pp
|
|
Activate a RAWIP link using Netgraph with:
|
|
.Bd -literal -offset indent
|
|
ngctl mkpeer lmc0: iface rawdata inet
|
|
ifconfig ng0 10.0.0.1 10.0.0.2
|
|
.Ed
|
|
.Pp
|
|
If the driver is unloaded and then loaded, reconnect hooks by:
|
|
.Pp
|
|
.Dl "ngctl connect lmc0: ng0: rawdata inet"
|
|
.\"
|
|
.Sh TESTING
|
|
.\"
|
|
.Ss Testing with Loopbacks
|
|
.\"
|
|
Testing with loopbacks requires only one card.
|
|
Packets can be looped back at many points: in the PCI chip,
|
|
in the modem chips, through a loopback plug, in the
|
|
local external equipment, or at the far end of a circuit.
|
|
.Pp
|
|
Activate the card with
|
|
.Xr ifconfig 8 :
|
|
.Pp
|
|
.Dl "ifconfig lmc0 10.0.0.1 10.0.0.1"
|
|
.Pp
|
|
All cards can be looped through the PCI chip.
|
|
Cards with internal modems can be looped through
|
|
the modem framer and the modem line interface.
|
|
Cards for external modems can be looped through
|
|
the driver/receiver chips.
|
|
See
|
|
.Xr lmcconfig 8
|
|
for details.
|
|
.Pp
|
|
Loopback plugs test everything on the card.
|
|
.Bl -tag -width ".Sy T1/E1"
|
|
.It Sy HSSI
|
|
Loopback plugs can be ordered from SBE (and others).
|
|
Transmit clock is normally supplied by the external modem.
|
|
When an HSSI card is operated with a loopback plug, the PCI bus
|
|
clock must be used as the transmit clock, typically 33 MHz.
|
|
When testing an HSSI card with a loopback plug,
|
|
configure it with
|
|
.Xr lmcconfig 8 :
|
|
.Pp
|
|
.Dl "lmcconfig lmc0 -a 2"
|
|
.Pp
|
|
.Dq Fl a Li 2
|
|
selects the PCI bus clock as the transmit clock.
|
|
.It Sy T3
|
|
Connect the two BNC jacks with a short coax cable.
|
|
.It Sy SSI
|
|
Loopback plugs can be ordered from SBE (only).
|
|
Transmit clock is normally supplied by the external modem.
|
|
When an SSI card is operated with a loopback plug,
|
|
the on-board clock synthesizer must be used.
|
|
When testing an SSI card with a loopback plug,
|
|
configure it with
|
|
.Xr lmcconfig 8 :
|
|
.Pp
|
|
.Dl "lmcconfig lmc0 -E -f 10000000"
|
|
.Pp
|
|
.Fl E
|
|
puts the card in DCE mode to source a transmit clock.
|
|
.Dq Fl f Li 10000000
|
|
sets the internal clock source to 10 Mb/s.
|
|
.It Sy T1/E1
|
|
A loopback plug is a modular plug with two wires
|
|
connecting pin 1 to pin 4 and pin 2 to pin 5.
|
|
.El
|
|
.Pp
|
|
One can also test by connecting to a local modem (HSSI and SSI)
|
|
or NI (T1 and T3) configured to loop back.
|
|
Cards can generate signals to loopback remote equipment
|
|
so that complete circuits can be tested; see
|
|
.Xr lmcconfig 8
|
|
for details.
|
|
.\"
|
|
.Ss Testing with a Modem
|
|
.\"
|
|
Testing with a modem requires two cards of different types.
|
|
.Bl -tag -width ".Sy T3/HSSI"
|
|
.It Sy T3/HSSI
|
|
If you have a T3 modem with an HSSI interface
|
|
(made by Digital Link, Larscom, Kentrox etc.\&)
|
|
then use an HSSI card in one machine and a T3 card in the other machine.
|
|
The T3 coax cables must use the null modem configuration (see below).
|
|
.It Sy T1/V.35
|
|
If you have a T1 (or E1) modem with a V.35, X.21 or EIA530 interface,
|
|
then use an SSI card in one machine and a T1 card in the other machine.
|
|
Use a T1 null modem cable (see below).
|
|
.El
|
|
.\"
|
|
.Ss Testing with a Null Modem Cable
|
|
.\"
|
|
Testing with a null modem cable requires two cards of the same type.
|
|
.Bl -tag -width ".Sy T1/E1"
|
|
.It Sy HSSI
|
|
Three-meter HSSI null-modem cables can be ordered from SBE.
|
|
In a pinch, a 50-pin SCSI-II cable up to a few meters will
|
|
work as a straight HSSI cable (not a null modem cable).
|
|
Longer cables should be purpose-built HSSI cables because
|
|
the cable impedance is different.
|
|
Transmit clock is normally supplied by the external modem.
|
|
When an HSSI card is connected by a null modem cable, the PCI bus
|
|
clock can be used as the transmit clock, typically 33 MHz.
|
|
When testing an HSSI card with a null modem cable, configure it
|
|
with
|
|
.Xr lmcconfig 8 :
|
|
.Pp
|
|
.Dl "lmcconfig lmc0 -a 2"
|
|
.Pp
|
|
.Dq Fl a Li 2
|
|
selects the PCI bus clock as the transmit clock.
|
|
.It Sy T3
|
|
T3 null modem cables are just 75-ohm coax cables with BNC connectors.
|
|
TX OUT on one card should be connected to RX IN on the other card.
|
|
In a pinch, 50-ohm thin Ethernet cables
|
|
.Em usually
|
|
work up to a few meters, but they will
|
|
.Em not
|
|
work for longer runs \[em] 75-ohm coax is
|
|
.Em required .
|
|
.It Sy SSI
|
|
Three-meter SSI null modem cables can be ordered from SBE.
|
|
An SSI null modem cable reports a cable type of V.36/EIA449.
|
|
Transmit clock is normally supplied by the external modem.
|
|
When an SSI card is connected by a null modem cable,
|
|
an on-board clock synthesizer is used.
|
|
When testing an SSI card with a null modem cable, configure it
|
|
with
|
|
.Xr lmcconfig 8 :
|
|
.Pp
|
|
.Dl "lmcconfig lmc0 -E -f 10000000"
|
|
.Pp
|
|
.Fl E
|
|
puts the card in DCE mode to source a transmit clock.
|
|
.Dq Fl f Li 10000000
|
|
sets the internal clock source to 10 Mb/s.
|
|
.It Sy T1/E1
|
|
A T1 null modem cable has two twisted pairs that connect
|
|
pins 1 and 2 on one plug to pins 4 and 5 on the other plug.
|
|
Looking into the cable entry hole of a plug,
|
|
with the locking tab oriented down,
|
|
pin 1 is on the left.
|
|
A twisted pair Ethernet cable makes an excellent straight T1 cable.
|
|
Alas, Ethernet cross-over cables do not work as T1 null modem cables.
|
|
.El
|
|
.\"
|
|
.Sh OPERATION NOTES
|
|
.\"
|
|
.Ss Packet Lengths
|
|
Maximum transmit and receive packet length is unlimited.
|
|
Minimum transmit and receive packet length is one byte.
|
|
.Pp
|
|
Cleaning up after one packet and setting up for the next
|
|
packet involves making several DMA references.
|
|
This can take longer than the duration of a short packet,
|
|
causing the adapter to fall behind.
|
|
For typical PCI bus traffic levels and memory system latencies,
|
|
back-to-back packets longer than about 20 bytes will always
|
|
work (53 byte cells work), but a burst of several hundred
|
|
back-to-back packets shorter than 20 bytes will cause packets
|
|
to be dropped.
|
|
This usually is not a problem since an IPv4 packet header is
|
|
at least 20 bytes long.
|
|
.Pp
|
|
This device driver imposes no constraints on packet size.
|
|
Most operating systems set the default Maximum Transmission
|
|
Unit (MTU) to 1500 bytes; the legal range is usually (72..65535).
|
|
This can be changed with
|
|
.Pp
|
|
.Dl "ifconfig lmc0 mtu 2000"
|
|
.Pp
|
|
SPPP enforces an MTU of (128..far-end-MRU) for PPP
|
|
and 1500 bytes for Cisco-HDLC.
|
|
RAWIP sets the default MTU to 4032 bytes,
|
|
but it can be changed to anything.
|
|
.\"
|
|
.Ss BPF - Berkeley Packet Filter
|
|
.\"
|
|
This driver has hooks for
|
|
.Xr bpf 4 ,
|
|
the Berkeley Packet Filter.
|
|
The line protocol header length reported to BPF is four bytes
|
|
for SPPP and P2P line protocols and zero bytes for RawIP.
|
|
.Pp
|
|
To include BPF support into your kernel,
|
|
add the following line to
|
|
.Pa conf/YOURKERNEL :
|
|
.Pp
|
|
.Dl "device bpf"
|
|
.Pp
|
|
To test the BPF kernel interface,
|
|
bring up a link between two machines, then run
|
|
.Xr ping 8
|
|
and
|
|
.Xr tcpdump 1 :
|
|
.Pp
|
|
.Dl "ping 10.0.0.1"
|
|
.Pp
|
|
and in a different window:
|
|
.Pp
|
|
.Dl "tcpdump -i lmc0"
|
|
.Pp
|
|
The output from
|
|
.Xr tcpdump 1
|
|
should look like this:
|
|
.Bd -literal -offset indent
|
|
03:54:35.979965 10.0.0.2 > 10.0.0.1: icmp: echo request
|
|
03:54:35.981423 10.0.0.1 > 10.0.0.2: icmp: echo reply
|
|
.Ed
|
|
.Pp
|
|
Line protocol control packets will appear among the
|
|
.Xr ping 8
|
|
packets occasionally.
|
|
.\"
|
|
.Ss Device Polling
|
|
.\"
|
|
A T3 receiver can generate over 100K interrupts per second,
|
|
this can cause a system to
|
|
.Dq live-lock :
|
|
spend all of its
|
|
time servicing interrupts.
|
|
.Fx
|
|
has a polling mechanism to prevent live-lock.
|
|
.Pp
|
|
.Fx Ns 's
|
|
mechanism permanently disables interrupts from the card
|
|
and instead the card's interrupt service routine is called each
|
|
time the kernel is entered (syscall, timer interrupt, etc.\&) and
|
|
from the kernel idle loop; this adds some latency.
|
|
The driver is permitted to process a limited number of packets.
|
|
The percentage of the CPU that can be consumed this way is settable.
|
|
.Pp
|
|
See the
|
|
.Xr polling 4
|
|
manpage for details on how to enable the polling mode.
|
|
.\"
|
|
.Ss SNMP: Simple Network Management Protocol
|
|
.\"
|
|
This driver is aware of what is required to be a Network Interface
|
|
Object managed by an Agent of the Simple Network Management Protocol.
|
|
The driver exports SNMP-formatted configuration and status
|
|
information sufficient for an SNMP Agent to create MIBs for:
|
|
.Pp
|
|
.Bl -item -offset indent -compact
|
|
.It
|
|
.%T "RFC-2233: Interfaces group" ,
|
|
.It
|
|
.%T "RFC-2496: DS3 interfaces" ,
|
|
.It
|
|
.%T "RFC-2495: DS1/E1 interfaces" ,
|
|
.It
|
|
.%T "RFC-1659: RS232-like interfaces" .
|
|
.El
|
|
.Pp
|
|
An SNMP Agent is a user program, not a kernel function.
|
|
Agents can retrieve configuration and status information
|
|
by using
|
|
Netgraph control messages or
|
|
.Xr ioctl 2
|
|
system calls.
|
|
User programs should poll
|
|
.Va sc->cfg.ticks
|
|
which increments once per second after the SNMP state has been updated.
|
|
.\"
|
|
.Ss HSSI and SSI LEDs
|
|
.\"
|
|
The card should be operational if all three green LEDs are on
|
|
(the upper-left one should be blinking) and the red LED is off.
|
|
All four LEDs turn on at power-on and module unload.
|
|
.Pp
|
|
.Bl -column -compact -offset indent "YELLOW" "upper-right" "Software"
|
|
.It "RED" Ta "upper-right" Ta "No Transmit clock"
|
|
.It "GREEN" Ta "upper-left" Ta "Device driver is alive if blinking"
|
|
.It "GREEN" Ta "lower-right" Ta "Modem signals are good"
|
|
.It "GREEN" Ta "lower-left" Ta "Cable is plugged in (SSI only)"
|
|
.El
|
|
.\"
|
|
.Ss T1E1 and T3 LEDs
|
|
.\"
|
|
The card should be operational if the upper-left green LED is blinking
|
|
and all other LEDs are off.
|
|
For the T3 card, if other LEDs are on or
|
|
blinking, try swapping the coax cables!
|
|
All four LEDs turn on at power-on and module unload.
|
|
.Pp
|
|
.Bl -column -compact -offset indent "YELLOW" "upper-right" "Received"
|
|
.It "RED" Ta "upper-right" Ta "Received signal is wrong"
|
|
.It "GREEN" Ta "upper-left" Ta "Device driver is alive if blinking"
|
|
.It "BLUE" Ta "lower-right" Ta "Alarm Information Signal (AIS)"
|
|
.It "YELLOW" Ta "lower-left" Ta "Remote Alarm Indication (RAI)"
|
|
.El \" YELLOW
|
|
.Pp
|
|
.Bl -column -compact "The yellow" "LED"
|
|
.It "The green" Ta "LED blinks if the device driver is alive."
|
|
.It "The red" Ta "LED blinks if an outward loopback is active."
|
|
.It "The blue" Ta "LED blinks if sending AIS, on solid if receiving AIS."
|
|
.It "The yellow" Ta "LED blinks if sending RAI, on solid if receiving RAI."
|
|
.El \" LED
|
|
.\"
|
|
.Ss E1 Framing
|
|
.\"
|
|
Phone companies usually insist that customers put a
|
|
.Em Frame Alignment Signal
|
|
(FAS) in time slot 0.
|
|
A Cyclic Redundancy Checksum (CRC) can also ride in time slot 0.
|
|
.Em Channel Associated Signalling
|
|
(CAS) uses Time Slot 16.
|
|
In telco-speak
|
|
.Em signalling
|
|
is on/off hook, ringing, busy, etc.
|
|
Signalling is not needed here and consumes 64 Kb/s.
|
|
Only use E1-CAS formats if the other end insists on it!
|
|
Use E1-FAS+CRC framing format on a public circuit.
|
|
Depending on the equipment installed in a private circuit,
|
|
it may be possible to use all 32 time slots for data (E1-NONE).
|
|
.\"
|
|
.Ss T3 Framing
|
|
.\"
|
|
M13 is a technique for multiplexing 28 T1s into a T3.
|
|
Muxes use the C-bits for speed-matching the tributaries.
|
|
Muxing is not needed here and usurps the FEBE and FEAC bits.
|
|
Only use T3-M13 format if the other end insists on it!
|
|
Use T3-CParity framing format if possible.
|
|
Loop Timing, Fractional T3, and HDLC packets in
|
|
the Facility Data Link are
|
|
.Em not
|
|
supported.
|
|
.\"
|
|
.Ss T1 & T3 Frame Overhead Functions
|
|
.\"
|
|
.Bl -item -compact
|
|
.It
|
|
Performance Report Messages (PRMs) are enabled in T1-ESF.
|
|
.It
|
|
Bit Oriented Protocol (BOP) messages are enabled in T1-ESF.
|
|
.It
|
|
In-band loopback control (framed or not) is enabled in T1-SF.
|
|
.It
|
|
Far End Alarm and Control (FEAC) msgs are enabled in T3-CPar.
|
|
.It
|
|
Far End Block Error (FEBE) reports are enabled in T3-CPar.
|
|
.It
|
|
Remote Alarm Indication (RAI) is enabled in T3-Any.
|
|
.It
|
|
Loopbacks initiated remotely time out after 300 seconds.
|
|
.El
|
|
.\"
|
|
.Ss T1/E1 'Fractional' 64 kb/s Time Slots
|
|
.\"
|
|
T1 uses time slots 24..1; E1 uses time slots 31..0.
|
|
E1 uses TS0 for FAS overhead and TS16 for CAS overhead.
|
|
E1-NONE has
|
|
.Em no
|
|
overhead, so all 32 TSs are available for data.
|
|
Enable/disable time slots by setting 32 1s/0s in a config param.
|
|
Enabling an E1 overhead time slot,
|
|
or enabling TS0 or TS25-TS31 for T1,
|
|
is ignored by the driver, which knows better.
|
|
The default TS param, 0xFFFFFFFF, enables the maximum number
|
|
of time slots for whatever frame format is selected.
|
|
56 Kb/s time slots are
|
|
.Em not
|
|
supported.
|
|
.\"
|
|
.Ss T1 Raw Mode
|
|
.\"
|
|
Special gate array microcode exists for the T1/E1 card.
|
|
Each T1 frame of 24 bytes is treated as a packet.
|
|
A raw T1 byte stream can be delivered to main memory
|
|
and transmitted from main memory.
|
|
The T1 card adds or deletes framing bits but does not
|
|
touch the data.
|
|
ATM cells can be transmitted and received this way, with
|
|
the software doing all the work.
|
|
But that is not hard; after all it is only 1.5 Mb/s second!
|
|
.\"
|
|
.Ss T3 Circuit Emulation Mode
|
|
.\"
|
|
Special gate array microcode exists for the T3 card.
|
|
Each T3 frame of 595 bytes is treated as a packet.
|
|
A raw T3 signal can be
|
|
.Em packetized ,
|
|
transported through a
|
|
packet network (using some protocol) and then
|
|
.Em reconstituted
|
|
as a T3 signal at the far end.
|
|
The output transmitter's
|
|
bit rate can be controlled from software so that it can be
|
|
.Em frequency locked
|
|
to the distant input signal.
|
|
.\"
|
|
.Ss HSSI and SSI Transmit Clocks
|
|
.\"
|
|
Synchronous interfaces use two transmit clocks to eliminate
|
|
.Em skew
|
|
caused by speed-of-light delays in the modem cable.
|
|
DCEs (modems) drive ST, Send Timing, the first transmit clock.
|
|
DTEs (hosts) receive ST and use it to clock transmit data, TD,
|
|
onto the modem cable.
|
|
DTEs also drive a copy of ST back towards the DCE and call it TT,
|
|
Transmit Timing, the second transmit clock.
|
|
DCEs receive TT and TD and use TT to clock TD into a flip flop.
|
|
TT experiences the same delay as (and has no
|
|
.Em skew
|
|
relative to) TD.
|
|
Thus, cable length does not affect data/clock timing.
|
|
.\"
|
|
.Sh SEE ALSO
|
|
.\"
|
|
.Xr tcpdump 1 ,
|
|
.Xr ioctl 2 ,
|
|
.Xr bpf 4 ,
|
|
.Xr kld 4 ,
|
|
.Xr netgraph 4 ,
|
|
.Xr polling 4 ,
|
|
.Xr sppp 4 ,
|
|
.Xr loader.conf 5 ,
|
|
.Xr ifconfig 8 ,
|
|
.Xr lmcconfig 8 ,
|
|
.Xr mpd 8 Pq Pa ports/net/mpd ,
|
|
.Xr ngctl 8 ,
|
|
.Xr ping 8 ,
|
|
.Xr ifnet 9
|
|
.\"
|
|
.Sh HISTORY
|
|
.\"
|
|
.An Ron Crane
|
|
had the idea to use a Fast Ethernet chip as a PCI interface
|
|
and add an Ethernet-to-HDLC gate array to make a WAN card.
|
|
.An David Boggs
|
|
designed the Ethernet-to-HDLC gate array and PC cards.
|
|
We did this at our company, LAN Media Corporation
|
|
.Tn (LMC) .
|
|
.Tn SBE
|
|
Corp.\& acquired
|
|
.Tn LMC
|
|
and continues to make the cards.
|
|
.Pp
|
|
Since the cards use Tulip Ethernet chips, we started with
|
|
.An Matt Thomas Ns '
|
|
ubiquitous
|
|
.Xr de 4
|
|
driver.
|
|
.An Michael Graff
|
|
stripped out the Ethernet stuff and added HSSI stuff.
|
|
.An Basil Gunn
|
|
ported it to
|
|
.Tn Solaris
|
|
(lost) and
|
|
.Tn Rob Braun
|
|
ported it to
|
|
.Tn Linux .
|
|
.An Andrew Stanley-Jones
|
|
added support
|
|
for three more cards and wrote the first version of
|
|
.Xr lmcconfig 8 .
|
|
.An David Boggs
|
|
rewrote everything and now feels responsible for it.
|
|
.\"
|
|
.Sh AUTHORS
|
|
.\"
|
|
.An "David Boggs" Aq boggs@boggs.palo-alto.ca.us
|